River Systems of West Bengal: Water and Environments (Springer Water) 3031534794, 9783031534799

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Springer Water

Gautam Kumar Das

River Systems of West Bengal Water and Environments

Springer Water

The book series Springer Water comprises a broad portfolio of multi- and interdisciplinary scientific books, aiming at researchers, students, and everyone interested in water-related science. The series includes peer-reviewed monographs, edited volumes, textbooks, and conference proceedings. Its volumes combine all kinds of water-related research areas, such as: the movement, distribution and quality of freshwater; water resources; the quality and pollution of water and its influence on health; the water industry including drinking water, wastewater, and desalination services and technologies; water history; as well as water management and the governmental, political, developmental, and ethical aspects of water.

Gautam Kumar Das

River Systems of West Bengal Water and Environments

Gautam Kumar Das Independent Researcher Kolkata, West Bengal, India

ISSN 2364-6934 ISSN 2364-8198 (electronic) Springer Water ISBN 978-3-031-53479-9 ISBN 978-3-031-53480-5 (eBook) https://doi.org/10.1007/978-3-031-53480-5 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Paper in this product is recyclable.

On the slope of the desolate river among tall grasses I asked her, ‘Maiden, where do you go shading your lamp with your mantle? My house is all dark and lonesome—lend me your light!’ She raised her dark eyes for a moment and looked at my face through the dusk. ‘I have come to the river,’ she said, ‘to float my lamp on the stream when the daylight wanes in the west’. I stood alone among tall grasses and watched the timid flame of her lamp uselessly drifting in the tide. Rabindranath Tagore Gitanjali, Poem No. LXIV

Dedicated to the people living riverside in the Bengal Basin

Preface

West Bengal in India is a diverse state with numerous river networks. Most of these rivers have no flow except during the rainy season. Wastewater discharged from towns or municipalities located along these non-flowing rivers increases the level of water pollution by entering the river water. The water chemistry of some of these rivers has been determined to measure the level of pollution in the river course section. Even if there are no towns or municipalities along the tributaries or distributaries of relatively large rivers, the river water is still contaminated due to the presence of fecal coliform bacteria which is caused by the discharge of waste materials from non-point sources. This type of river water is unfit for consumption and even for outdoor bathing. The water quality index is computed by applying statistical formulas, and the impact of those indices for polluted stretches of the rivers is included in this book. Apart from water quality rating, the issue of inter-basin transfer of water resources with respect to some rivers of West Bengal is discussed in the book chapters. Although West Bengal is not an earthquake-prone region, land subsidence occurs over time as it belongs to the Gangetic Delta region and that is why the river often changes direction of its course and starts flowing from the old course to the new river channel. Abandoned riverbeds remain in the form of canals, lakes, and waterbodies where human activity continues. Local people cultivate fish there, plant trees along the riversides to create social forests, or float boats on the water to develop tourism centers in the area and thus begin the amalgamation of man, society, and nature from which the concept of river commons originated. As most of the rivers in West Bengal flood during the monsoons, dams and reservoirs have been built over the rivers to prevent flooding. Crop production in the river catchment areas has been doubled through irrigation from these reservoirs. The use of river water resources has been successful through the application of science and by the initiatives of the state government. Most of the rivers in West Bengal are unique for their nature and characteristics. Therefore, apart from the nature and characteristics of the rivers in general, the water of about ten rivers is sampled and analyzed and has been discussed in separate chapters in this book. Scientific management of river basins is required to get the benefits of river systems. Flooding cannot always be prevented by damming the course of the river. On ix

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the other hand, flooding is seen due to the release of excess water during the monsoon for the construction of reservoirs by damming the river. Floods make life miserable even after river planning. It causes loss of life and property. But hundreds of years ago, there were not so many dense settlements on both sides of the river. Rather, there were dense forests on the riversides. During the monsoons, floods occurred in most of them annually. That flood did not create fear or terror in people’s minds, or people’s houses were not always destroyed by that flood, or that flood did not displace people. Rather, that flood caused by the water bursting from both sides of the river was a joy and celebration for a good hope of more crops in the ensuing years. Dense population and unplanned urbanization along the river course are the causes of floods in the present day. Scientific planning of river management was initiated to prevent these floods. But most of the river management in West Bengal is hampered due to geographical reasons because the origin or confluence of rivers is in different states or in the neighboring countries. A small state like West Bengal has to bear the brunt of excess rainfall, landslides, soil erosion, and natural calamities of other countries or states. Excavation of several reservoirs to retain rainwater across river basins could be a solution, but land for digging reservoirs in a small state like West Bengal is almost scarce. In spite of all this, the occurrence of severe floods in many rivers has been greatly reduced by the construction of river dams, barrages, and reservoirs. Reservoir-derived irrigation water has led to a green revolution in crop yields in some places. It is becoming possible to generate hydroelectric power even if it is small in quantity. Reservoir water is being supplied to the thermal power plant in necessity. In short, river management has become a part of human resources that can be called ‘river commons’ with the application and implementation of science, technology, and engineering. This book is a testament to this shared interdependence of social, anthropogenic, and science of the river systems of West Bengal. The book may be purported to be the window of expression of day-to-day love for rivers experienced by the author in living by the riverside since his childhood where he is a part of the rivers as the river becomes a part of the author. In consequence, a vast experience for years related to drainage systems, inland waterways, transport and communications, flood control, aquaculture, agriculture, and irrigation including water resources are gathered directly from the nature that helps the author in performing rigorous survey and analysis of the river systems of West Bengal. Though the tidal and fluvial arteries of numerous rivers are a very vast platform for research works with different magnitudes and dimensions, the present book is restricted on the water and environment of some selected rivers with a glimpse of societal aspects in a broad spectrum in the state of West Bengal. Kolkata, India August 2023

Gautam Kumar Das

Acknowledgements

It is impossible to name all those who contributed to this book based on my fieldwork and laboratory analysis for several decades. I owe an immeasurable amount of gratitude to Manjari Bhattacharya, Professor, Visva-Bharati University who supported me in countless ways throughout the duration of my research. This research would have been much poorer without her deep insightful comments and corrections. I am profoundly indebted to S. Rakshit, Former Director, Geological Survey of India for his constant encouragement and incredible generosity, and particularly for his rigorous review of the draft manuscript for several times. The author acknowledges the help rendered by the Director General, India Meteorological Department (IMD), the Directors of River Research Institute (RRI), River Rejuvenation Committee, Geological Survey of India (GSI), and Zoological Survey of India (ZSI) and Secretaries, Central Pollution Control Board and West Bengal Pollution Control Board, including the various helps and laboratory facilities provided by the Head, Department of Chemical Engineering, Jadavpur University. I express my deep sense of gratitude to Prof. Siddhartha Datta, Former Pro-Vice Chancellor, Jadavpur University as he offered many fruitful suggestions for its improvement. I gratefully acknowledge the constant support and encouragement received from Margaret Deignan, Senior Editor, Springer Nature during the entire period of manuscript preparation. The book would have been impossible to complete without her inspiration and support.

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1

River Systems of West Bengal: Water Quality and Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 River Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1.1 Ganga Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Mahananda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Damodar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Ajoy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 Rasulpur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 Brahmaputra Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6.1 Torsa–Kaljani Subbasin . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 Teesta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 Raidak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 Jaldhaka . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.10 Sankosh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.11 Subarnarekha Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.12 Rivers of Sunderbans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.13 Shifting of River Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.14 River Commons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.15 Interbasin Transfer of Water Resources . . . . . . . . . . . . . . . . . . . . . 1.16 River Pollution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.17 Water Quality Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.18 Abandoned Channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.18.1 Kal Dighi and Dhal Dighi . . . . . . . . . . . . . . . . . . . . . . . . . 1.19 Riverine Civilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.19.1 Tulaipanji—A Brand Produce from Kulik-Nagar Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.20 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 1 2 8 9 10 10 10 11 11 11 12 12 12 12 13 14 15 16 17 19 23 24 24 25 26

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2

Shilabati River and Its Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Shilabati River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Myths and Local Belief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Environmental Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.1 Gangani . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Riverine Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 River Water Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.1 Water Quality Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29 29 30 31 32 33 34 36 36 37

3

Environmental Deterioration of Churni River . . . . . . . . . . . . . . . . . . . . 3.1 River Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Churni River Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Anjana River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4 Mathabhanga River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 Fish and Fishing Community . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6 Water Quality Determinants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6.1 Biochemical Oxygen Demand . . . . . . . . . . . . . . . . . . . . . 3.6.2 pH and Biochemical Oxygen Demand . . . . . . . . . . . . . . 3.6.3 Nutrients and Biochemical Oxygen Demand . . . . . . . . . 3.6.4 Microbial Organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6.5 Chemical Oxygen Demand . . . . . . . . . . . . . . . . . . . . . . . . 3.7 River Water Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7.1 Water Quality Index (WQI) . . . . . . . . . . . . . . . . . . . . . . . 3.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

39 39 40 42 42 45 45 45 46 47 47 48 49 50 52 53

4

Mayurakshi River—Water Resources and Environments . . . . . . . . . 4.1 Mayurakshi River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Riverine Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Mayurakshi–Babla River Systems . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.1 Kopai . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.2 Kuiya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3.3 Dwaraka . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Catchment Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Flood Situations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 Shifting of River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 River Commons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 River Water Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8.1 Total Suspended Solids . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8.2 Total Alkalinity and Hardness . . . . . . . . . . . . . . . . . . . . . 4.9 Water Quality Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

55 55 56 57 57 58 58 58 59 59 61 62 62 63 63 64 65

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Water Quality Rating of Damodar River . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Damodar River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Shifting of River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 Damodar River System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Barakar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Damodar Valley Corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 Impact of Dams and Barrages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7 Natural Vegetation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7.1 Mahua and Its Products . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7.2 Susunia Hill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7.3 Eucalyptus Plantation in Badlands . . . . . . . . . . . . . . . . . 5.7.4 Environmental Feasibility Test for Eucalyptus . . . . . . . 5.7.5 Statistical Computation . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8 Water Quality Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.9 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67 67 68 70 70 70 72 75 75 77 80 82 83 86 87 87

6

Changing Water Quality of Jalangi River . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Jalangi River Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 River Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Clay Dolls of Krishnanagar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 River Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5 Physicochemical Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5.1 Turbidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5.2 Ammonium Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6 Water Quality Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6.1 Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

91 91 93 93 94 95 96 96 97 99 99 99

7

Environmental Morphodynamics of Rupnarayan River . . . . . . . . . . . 7.1 Rupnarayan River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 River Morphodynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Riverbank Erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 Riverbank Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 River Water Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6 Changing Water Characteristics for Climate Change . . . . . . . . . . 7.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

103 103 105 106 108 109 110 112 113

8

Water and Environments of Kangsabati River . . . . . . . . . . . . . . . . . . . 8.1 Kangsabati River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Kangsabati River System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2.1 Saharjhora . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2.2 Bandu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2.3 Kumari . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

115 115 117 117 117 118

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8.2.4 Bhairabbanki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2.5 Keleghai–Kapaleshwari . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3 The Myth and Keleghai . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4 Illegal Soil Mining and Selling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5 Haldi River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.6 Shifting of River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7 Kangsabati Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8 River Commons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8.1 Khirai—A Flowery Village . . . . . . . . . . . . . . . . . . . . . . . 8.9 River Water Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.9.1 pH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.9.2 Dissolved Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.10 Physicochemical Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.11 Faecal Coliform Bacteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.12 Water Quality Indices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.13 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

118 118 118 119 119 120 120 120 121 123 123 123 124 124 125 126 126

Water Quality Determinants of Mathabhanga, Churni and Jalangi Rivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 Churni–Mathabhanga–Ichhamati River Systems . . . . . . . . . . . . . 9.1.1 Churni and Jalangi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1.2 Anjana . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1.3 Mathabhanga . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1.4 Ichhamati . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 Commons of Riverside Countries . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 Physicochemical Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4 River Water Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5 Water Quality Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

129 129 129 132 132 134 135 135 135 137 138 138

10 River Environments of North Bengal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1 North Bengal Rivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2 River Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.1 Karala . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.2 Jaldhaka . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.3 Raidak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.4 Sankosh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.5 Torsa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.6 Kulik . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.7 Nagar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.8 Mahananda and Kalindi . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.9 Atreyi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3 Shifting of River Courses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4 River Commons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

141 142 142 142 143 143 143 144 144 144 145 146 146 147

9

Contents

xvii

10.5 Teesta Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.6 Traditional River Fishes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.7 Water Quality Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

147 149 150 151 152

11 Bidyadhari—A Sewage-Fed Tidal River . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Bidyadhari River Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Bidyadhari River Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2.1 Sakha Bidyadhari . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2.2 Piyali . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2.3 Adi Ganga . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 Riverside Vegetation of Adi Ganga . . . . . . . . . . . . . . . . . . . . . . . . 11.4 Drainage Canals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.5 River Environment and Water Quality . . . . . . . . . . . . . . . . . . . . . . 11.6 Natural Remedy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.7 River Commons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.8 Ethnological Diversity in Sunderbans . . . . . . . . . . . . . . . . . . . . . . 11.9 Tribal Recreations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.10 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

155 155 156 157 158 158 159 160 161 162 163 164 165 167 167

12 Water Quality Rating of Kolkata Waterbodies . . . . . . . . . . . . . . . . . . . 12.1 Urban Wetlands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2 Wetland Vegetation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3 Physicochemical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.4 Surface Water Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.5 Water Quality Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.6 Remedial Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.7 Wetland Commons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

171 171 174 175 175 177 177 178 179 179

About the Author

Gautam Kumar Das is a researcher, well known in the field of environmental assessment, monitoring, and modeling of the rivers, coasts, forests, estuaries, and Sundarbans.

xix

Abbreviations

BOD COD CPCB DBH DO DOM DVC DWFC EC ETPs FAS FC GPI IMD MHaM MPN MW NH ppt RRI SPI SWFC TA TC TDS TFS TH TKN TOC

Biochemical Oxygen Demand Chemical Oxygen Demand Central Pollution Control Board Diameter at Breast Height Dissolved Oxygen Dissolved Organic Matter Damodar Valley Corporation Dry Weather Flow Channel Electrical Conductivity Effluent Treatment Plants Ferrous Ammonium Sulfate Fecal Coliform Grossly Polluting Industries India Meteorological Department Million Hectare Meters Most Probable Number Megawatts National Highways Parts Per Thousand River Research Institute Seriously Polluting Industries Storm Weather Flow Channel Total Alkalinity Total Coliform Total Dissolved Solids Total Fixed Solids Total Hardness Total Kjeldahl Nitrogen Total Organic Carbon

xxi

xxii

TSS WBPCB WQI

Abbreviations

Total Suspended Solids West Bengal Pollution Control Board Water Quality Index

List of Figures

Fig. 1.1 Fig. 1.2

Fig. 2.1 Fig. 2.2 Fig. 3.1 Fig. 3.2 Fig. 3.3 Fig. 4.1

Fig. 5.1

Fig. 5.2

Fig. 6.1 Fig. 7.1

Map showing the geographical locations of the rivers of West Bengal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Confluence of Kulik (right) and Nagar (left) near Raiganj in Uttar Dinajpur district and both the rivers are connected with the temporary bamboo-made bridge during the lean period for easy movement of the locals . . . . . . . . . . . . . . . . . . . . . Shilabati River at Gangani near Garbeta of Paschim Medinipur district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shilabati River with huge turbid water at its downstream of Ghatal, Paschim Medinipur . . . . . . . . . . . . . . . . . . . . . . . . . . . . Churni River at Aranghata in Nadia district . . . . . . . . . . . . . . . . . Anjana River covered with water hyacinth at Badkulla of Nadia district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mathabhanga River at Majdia in Nadia district . . . . . . . . . . . . . . . Construction of revetments by using boulders for remedial measures of bank erosion and temporary road across Mayurakshi River for easing transport and communication facilities almost blocked the river course near Sainthia town in Birbhum district . . . . . . . . . . . . . . . Durgapur Barrage over Damodar River in Paschim Bardhaman district. Note the reservoir water is almost covered with the water hyacinth . . . . . . . . . . . . . . . . . . . . . . . . . . . Eucalyptus plantation site in the recorded forest areas standing nearby Ausgram Forest Beat under Guskara Range of Bardhaman Forest Division in West Bengal . . . . . . . . . Seasonal jute processing activities by the locals in Jalangi River at the outskirt of Krishnanagar municipal areas . . . . . . . . . Confluence of Rupnarayan and Hooghly rivers at Geonkhali of Purba Medinipur district (top) and Gadiara of Howrah district (below) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

9 33 35 41 43 44

56

71

84 92

104

xxiii

xxiv

Fig. 7.2

Fig. 7.3

Fig. 7.4

Fig. 8.1 Fig. 8.2 Fig. 9.1 Fig. 9.2

Fig. 9.3 Fig. 9.4 Fig. 10.1 Fig. 10.2 Fig. 11.1 Fig. 11.2

Fig. 12.1 Fig. 12.2

List of Figures

Origin of Rupnarayan River (right) from the union of Dwarakeswar (mid-stream) and Shilabati (left) rivers at Bandar near Ghatal of Paschim Medinipur district . . . . . . . . . . Location map of Rupnarayan-Hooghly River confluence surrounded by Purba Medinipur, Howrah and South 24 Parganas districts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Graphical representation of laminar sublayer thickness against roughness height of Rupnarayan River at Natshal of Purba Medinipur district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kangsabati River course near Moyna in Purba Medinipur district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kangsabati reservoir at Mukutmanipur in Bankura district . . . . . Blackish water flow along the course of Churni River at Aranghata of Nadia district, West Bengal . . . . . . . . . . . . . . . . . Jute processing by the local farmers in the river waters of Jalangi at Krishnanagar downstream in Nadia district of West Bengal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anjana River at Badkulla of Nadia district covered with water hyacinths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water quality indices of the surface water samples of Churni, Mathabhanga and Jalangi rivers . . . . . . . . . . . . . . . . . . Kulik River—the habitat for the traditional local fishes near Raiganj town in Uttar Dinajpur district . . . . . . . . . . . . . . . . . The newly constructed Teesta Canal now functioning at Gajoldoba in Jalpaiguri district . . . . . . . . . . . . . . . . . . . . . . . . . Bidyadhari River near its source of origin at Ashoknagar in North 24 Parganas district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bidyadhari River at its downstream stretch near Malancha of North 24 Parganas. Note the series of brick kiln along the riverside areas of Bidyadhari . . . . . . . . . . . . . . . . . . . . . Rabindra Sarovar Waterbody in the heart of the city of joy . . . . . The waterbody of Rabindra Sarovar, also known as Dhakuria Lake, where all types of anthropogenic activities like washing of cloths and cooking utensils, outdoor bathing, throwing of solid wastes like polyethene, plastic packets, papers, rotten foods including flowers and fruits for the activities for religious rituals or festivals are completely prohibited by the Kolkata Metropolitan Development Authority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

105

107

108 116 117 130

131 133 137 145 148 157

163 173

174

List of Tables

Table 1.1 Table 1.2 Table 1.3 Table 2.1 Table 3.1 Table 3.2 Table 4.1 Table 5.1

Table 5.2 Table 6.1 Table 6.2 Table 6.3

Table 7.1 Table 8.1

River basins, Sub-basins, and tributaries of the river systems of West Bengal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Comparative studies on the polluted stretches of the rivers in West Bengal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Computation of Water Quality Index (WQI) for water quality rating of the river waters of West Bengal . . . . . . . . . . . . Water quality index of river water of Shilabati River at Ghatal downstream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Computed water quality index of river waters at different locations of Churni . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Computed water quality index of river waters at downstream stretch of Mathabhanga . . . . . . . . . . . . . . . . . . . . Water quality indices of the surface water samples of Mayurakshi-Dwaraka river systems . . . . . . . . . . . . . . . . . . . . Number of trees observed in the Eucalyptus plantation site in 2022 at Ausgram Forest Beat of Bardhaman Forest Division . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water quality indices of the surface water samples of Damodar and Barakar rivers . . . . . . . . . . . . . . . . . . . . . . . . . . Modified standard values of individual parameters for the computation of water quality index (WQI) . . . . . . . . . . . Water Quality Index (WQI) of water samples of Jalangi River at Krishnanagar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water quality index of river waters of Jalangi at downstream of Krishnanagar for the period from January to May 2020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water Quality Index (WQI) of samples collected at different locations of Rupnarayan River . . . . . . . . . . . . . . . . . Water quality indices of the river water of Kangsabati at Gandhi Ghat area in the Midnapore town . . . . . . . . . . . . . . . .

4 18 20 36 51 51 64

85 86 97 98

99 110 125

xxv

xxvi

Table 10.1 Table 11.1 Table 11.2 Table 12.1 Table 12.2 Table 12.3

List of Tables

Water quality indices of the surface water samples of the rivers of North Bengal . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wetland plants, phytoplankton, and zooplanktons from the wetland environments of Adi Ganga . . . . . . . . . . . . . . Water quality index (WQI) of the surface water samples of Bidyadhari River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Medicinal plant species surrounding waterbodies in and around Kolkata metropolis . . . . . . . . . . . . . . . . . . . . . . . . Analysis of surface water samples of the waterbodies in and around Kolkata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Water quality index values of the water bodies in and around Kolkata metropolis . . . . . . . . . . . . . . . . . . . . . . . .

151 160 163 175 176 177

Chapter 1

River Systems of West Bengal: Water Quality and Environment

Abstract Numerous rivers flow across the state of West Bengal forming a river network with the tributaries and distributaries of these rivers across the state. The principal river basins in the state are Ganga, Brahmaputra, and Subarnarekha which form a number of subbasins in the land of Bengal. Rivers in majority change their courses in all directions and such shifting of river courses cause the changing scenario of the direction of flow with space and time. Interbasin transfer of river water helps in irrigation and flood control and was introduced in the state of West Bengal in the British era. River commons happen to be a social contract which is closely related with the common properties’ resources of the riverside people. Among these rivers, which have water throughout the year, problems like water pollution are relatively less. During the dry season, pollution levels are high for factories or municipalities located along rivers with knee-dip water. Recently, thirteen river stretches in West Bengal have reached such levels of water pollution that they are not even suitable for outdoor bathing. Using the physicochemical parameters obtained from these stretches of the rivers, water quality indices were computed and after that the water quality rating was determined. From the obtained values of water quality rating, it is observed that the water quality of most of the river stretches in West Bengal is quite poor and often below the permissible limit. Keywords River basins · River systems · River commons · Shifting of river courses · Inter-basin water transfer · River pollution · Water quality indices

1.1 River Systems West Bengal, characterized with the topographical diversity, is one of the states of India crowned by the Himalayan range in the north and ends its territorial extension on the lap of the Bay of Bengal in the south. Along with such geography of the north–south elongated state, a series of small mountains are scattered in the Chhotonagpur plateau in the west. The entire topographical feature of West Bengal favours the drainage systems to flow from the north and northwest to south and southeast

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_1

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1 River Systems of West Bengal: Water Quality and Environment

direction with a network of fluvial arteries in the form of streams, tributaries, distributaries, rivulets, creeks, channels, tidal courses and inlets (Fig. 1.1). The state of West Bengal is crisscrossed with innumerable major and minor drainage systems having several river basins and sub-basins including the river catchment areas. From the western and north-eastern side, Ganga and Brahmaputra, two biggest rivers of the Indian subcontinent flow along the state of West Bengal and Bangladesh and meet in Bangladesh. A large number of tributaries and distributaries of the central, southern and southwestern parts of the state is mainly catered through Ganga or into Bhagirathi-Hooghly, its distributary and the drainage of the northern Brahmaputra revealing demarcation of the state of West Bengal under two river basins i.e., Ganga and Brahmaputra. Both the major drainage systems Ganga and Brahmaputra have a dense network of fluvial arteries being crisscrossed by the numerous tributaries and distributaries. Apart from the Ganga and Brahmaputra, the Subarnarekha basin is included in the drainage systems, and it occupies a small area in the state of West Bengal. Further, the tidal rivers of the Sunderbans, once the distributaries of Hooghly River deserve special attention as a separate basin of the state of West Bengal [11]. The tidal river networks of the Sunderbans within the Hooghly–Matla estuarine complex have no headwater discharge as they were disconnected about a century back from the Hooghly River due to the regional geological changes of the Bengal Basin for plate tectonics [16, 17]. Above all, the Ganga, Brahmaputra, Subarnarekha, and Sunderbans tidal river systems are the principal river basins and are characterized with different sub-basins along with the specific catchment areas (Table 1.1). Among tributaries, distributaries, inlets, and river courses, water quality and environmental scenario of only eleven rivers are considered for the study on the basis of the magnitude of pollution level, vulnerability of environmental degradation, and standing municipalities and industries on the riverside along the river courses across the state of West Bengal.

1.1.1 Ganga Basin A number of fluvial and tidal arteries of Ganga River crisscrossed the state in the form of tributaries, distributaries, and tidal inlets constitute the Ganga Basin in the state of West Bengal. A total catchment area of 73,833 km2 under different rivers within the Ganga systems comprises a tidal and fluvial artery from the north to south in the state of West Bengal.

1.1.1.1

Mayurakshi–Babla Subbasin

Mayurakshi, also known as Mor River, is about 250 km in length and originates from Trikut Hill of Jharkhand. The river, including most of its tributaries rises in the Santhal Parganas of Jharkhand and outfalls into Bhagirathi River near Bharatpur in Murshidabad district taking the name of Babla. The river system contains Mayurakshi,

1.1 River Systems

Fig. 1.1 Map showing the geographical locations of the rivers of West Bengal

3

4

1 River Systems of West Bengal: Water Quality and Environment

Table 1.1 River basins, Sub-basins, and tributaries of the river systems of West Bengal Basins

Areas in West Bengal (km2 )

Sub-basins

Tributaries

Brahmaputra Basin

11,860

Teesta

Great Rangit, Raman, Rangpo, Relli, Lish, Ghish, Chel, Neora, Karala

Torsa–Kaljani

Kaljani, Sil Torsa, Char Torsa, Sanjai, Holong, Ghargharia, Garam, Dima, Pana, Jayanti, Gabur-Basra

Jaldhaka

Mujnai, Murti, Diana, Sutanga, Dolong, Dharala, Ghatia, Kumlai, Gilandi, Duduya

Raidak

Raidak-I, Raidak-II, Turturi

Sankosh

Chiklajhara

Mahananda

Mechi, Balason, Dauk, Nagar, Kulik, Gamar, Chiramati, Tangon, Kalindi

Atrai–Punarbhaba

Sahu Nim, Talma, Chaoai, Panga, Karatowa, Dhepa

Pagla–Bansloi

Pagla Bansloi, Bagmari

Brahmani–Dwaraka

Brahmani, Dwaraka

Jalangi–Bhairab

Jalangi, Anjana, Sialmari, Bhairab, Sati, Kharia

Churni – Ichhamati

Mathabhanga, Churni, Ichhamati

Mayurakshi–Babla

Mayurakshi, Babla, Noon Beel, Siddheswari, Kuiya, Bakreswar, Kopai, Sal, Manikarnika, Daoki, Kana Mor, Gambhir

Ajoy

Ajoy, Hinglow, Kunnor

Khari–Gangur–Ghea

Khari, Brahmani, Banka, Gangur, Ghea, Behula, Kana

Damodar

Damodar, Barakar, Sali

Dwarakeswar

Gandheswari, Arkasha, Berai

Rupnarayan–Silabati

Mundeswari, Dwarakeswar, Gandheswari, Amodar, Tarajuli, Silabati, Jayapanda, Kulbai or Kubai, Tamal and Parang

Kangsabati–Keleghai–Haldi

Haldi, Kangsabati, Kumari, Bhairal, Banki, Tarafeni, Keleghai, Baghai, Chandia, Kapaleswari

Ganga Basin

73,833

(continued)

1.1 River Systems

5

Table 1.1 (continued) Basins

Areas in West Bengal (km2 )

Rivers of Sunderbans

Subarnarekha Basin

11,320

2160

Sub-basins

Tributaries

Bhagirathi–Hooghly

Mayurakshi, Ajoy, Damodar, Churni, Jalangi, Rupnarayan, Haldi, Rasulpur

Rasulpur

Bagada, Sarpai, Madhakhali, Rasulpur

Hooghly–Matla

Thakuran, Matla, Saptamukhi, Muri Ganga, Piali, Raidighi, Kalindi, Haribhanga, Kalagachia, Hogol, Gumdi, Bidya, Ichhamati, Raimangal, Dansa, Kulti Gung, Bidyadhari, Keorapukur, Adi Ganga, Gosaba, Moni, Durga Doani, Chinai, Hatania Doania, Mridanga Bhanga, Kalchera, Jagadal, Hana, Gobadia, Kalnagini

Subarnarekha

Subarnarekha, Dulung

Bakreswar, Kopai, Kuiya, Manikarnika, Brahmani, Gambhira, Dwaraka, Khuskarni, Siddheswari, Noonbali, and Babla rivers and streams that constitute the river network in Birbhum and part of the Murshidabad district. Along the river course, below 7 km of Massanjore dam, Mayurakshi meets Siddheswari–Noonbali, the combined flow of its tributaries. Again, at the upstream of Tilpara barrage, Khuskarni, a small stream outfalls into Mayurakshi River. In the mid-stretch, Mayurakshi River joins the Kuiya River. Kuiya River is a resultant flow of the union of Bakreswar and Kopai rivers. Kopai is also known as Sal River in Birbhum district. At the downstream stretch, Dwarka outfalls into Mayurakshi River at Hijal Beel and the combined flow meets Bhagirathi at their confluence taking the name of Babla.

1.1.1.2

Jalangi–Bhairab Subbasin

Jalangi, also known as Kharia at its lowest reaches, originates from the right bank of Padma River at Hasanpur in Murshidabad district. Hasanpur, the source of Jalangi River is about 165 km away from Farakka. Jalangi now almost deserted at its mouth for lacking headwater discharge, has had a full swing of glorious past with surface water ripples when a huge quantum of discharge flows into Jalangi from Padma River. The river regains its life only for a few days when water flows from Padma to Jalangi during heavy rainfall in monsoon. The situation of the confluence of Jalangi and Bhairab remains a desert-like look covered with white sands as they are lacking

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1 River Systems of West Bengal: Water Quality and Environment

water flow from the upstream. Bhairab, Sialmari, Gobra-Suti Nala, Kalma Khal, Saraswati Khal, Bhairab Khal, Kesto-Raier Khal and Anjana are the tributaries of Jalangi River. Jalangi outfalls into Bhagirathi River at Swarupganj near Mayapur, opposite to Nabadwip of Nadia district and the river course of Bhagirathi flows taking the name of Hooghly after the confluence of Jalangi–Bhagirathi that demarcates the borderline of Hooghly and North 24 Parganas districts. Bhairab, a tributary of Jalangi River, originates from Ganga River near Lalbagh of Murshidabad district. The source of Bhairab River and the confluence of Mahananda– Ganga is on the opposite side i.e., right, and left bank of the Ganga respectively. Most part of the river Bhairab is presently deserted, and the rest is in dying condition. Some parts of the paleochannel of Bhairab is visible in Bangladesh which is considered to be older in age than the existing one. Bhairab, almost a dead river, looks like a river only when water flows from Padma River and enters Bhairab River.

1.1.1.3

Mathabhanga–Churni–Ichamati Subbasin

Mathabhanga River bifurcates to form Churni and Ichamati river systems at Majdia in Nadia district of West Bengal. A distributary as well as the western branch of Mathabhanga River after its bifurcation, Churni River flows across the Nadia district in the southwest direction and ultimately outfalls in Hooghly River at Shibpur in Nadia district, opposite to Gosair Char of Hooghly district. On the contrary, the eastern branch Ichamati River after the bifurcation of Mathabhanga River flows opposite to the river course of Churni lacking headwater discharge from the Mathabhanga River due to some geographical reasons. Ichamati River, by far a transboundary river, is a tidal river at its downstream stretch. The upstream flow of the river is almost stagnant, covered mostly with water hyacinth and the riverbed is filled only with water from the rainfall during the rainy days. The source of origin of both Churni and Ichamati is Mathabhanga which rises from the river Padma near Kushtia in Bangladesh. Mathabhanga enters India near Darshana-Gede international border and flows only a few kilometers in Nadia district before its bifurcation to form Churni and Ichamati, its two distributaries.

1.1.1.4

Pagla–Bansloi–Brahmani Subbasin

Brahmani, a tributary of Dwarka River, originates from Rajmahal Hills in Jharkhand state of northeastern India. The Brahmani River flows in the eastern direction and enters Birbhum district of West Bengal bisecting Rampurhat Subdivision and joins Dwarka River. Bansloi River rises from Bans Hill in Sahibganj district of Santhal Parganas, is a tributary of Bhagirathi. Pagla River, a tributary of Ganga River, is separated from Ganga for the construction of an embankment that changes the nature of the river from a perennial to a monsoon rainfall dependent river.

1.1 River Systems

1.1.1.5

7

Dwarakeswar–Shilabati–Rupnarayan Subbasin

Several rivers like Gandheswari, Dwarakeswar, Amodar, Tarajuli, Adhusa, Borai, Silabati, Joypanda, Kulbai or Kubai, Tamal, Parang, Mundeswari, Old Kansai or Palaspai Khal, and Rupnarayan constitute the Dwarakeswar–Silabati–Rupnarayan System. In this river system, Silabati originates at Puncha of Purulia district which has a number of tributaries like Joypanda, Kulbai or Kubai, Tamal and Parang. Apart from Silabati, Dwarakeswar originating from Purulia district is the main river of Bankura district and the river Gandheswari meets with Dwarakeswar just below Bankura town. Gandheswari originates at Saltora in Bankura. After receiving the discharge from the stream like Adhusa and Borai the combined flow of Gandheswari and Dwarakeswar flow along the Hooghly district taking the name of Dwarakeswar and ultimately it meets with Shilabati River at Bandar near Ghatal of Paschim Medinipur district. Rupnarayan River originates from the confluence of Dwarakeswar and Silabati rivers i.e., the lower stretch of the union of Dwarakeswar and Shilabati is known as Rupnarayan River. Along its course, Rupnarayan receives the major share of discharge of Damodar River through its main channel Mundeswari after the bifurcation of the latter at Pansuli. Then Old Kansai or Palaspai Khal, a branch of Kangsabati River meets Rupnarayan River and makes it a rather wide one. Rupnarayan River, considered as the biggest River of Purba Medinipur district outfalls into Hooghly River at Geonkhali of Purba Medinipur that demarcates the boundaries of Howrah, South 24 Parganas, and Purba Medinipur districts.

1.1.1.6

Kangsabati–Keleghai–Haldi Subbasin

Kangsabati originates from Purulia district and joins Kumari River, its tributary at Mukutmanipur in Bankura district. The Kangsabati (also known as Kansai) meets the combined flow of Tarafeni and Bhairab–Banki and flows in the Paschim Medinipur district thereafter. The river is divided at Kapastikri and further down, the upper branch of Kangsabati, known as Old Kansai or Palaspai Khal joins Rupnarayan River near Gopiganj whereas the other branch of Kangsabati, known as New Kansai, meets Keleghai, the combined flow of Kapaleshwari, Baghai, and Chandia and form Haldi River. Kaliaghai rises from Jhargram district and flows along Paschim Medinipur and Purba Medinipur districts before its union with New Kansai to form Haldi River at Tangrakhali of Purba Medinipur district. The Haldi River, a combined flow of Kaliaghai or Keleghai, Kapaleshwari, and New Kansai rivers, is an important drainage system in Purba Medinipur district which ultimately meets Hooghly River estuary at Haldia. Haldia is named after Haldi River.

1.1.1.7

Atrai–Punarbhaba Subbasin

River Atrai is known as Karatowa in Jalpaiguri at its upper reach and Karatowa is a combined flow of Talma, Panga, Sahu Nim, and Chaoai originating from the

8

1 River Systems of West Bengal: Water Quality and Environment

foothills of the Himalayan Range. Then Karatowa enters Bangladesh and takes the name of Atrai. Atrai River bifurcates into Dhepa and Atrai. Atrai again bifurcates in West Bengal near Kumarganj in Dakshin Dinajpur district. Balurghat town, the headquarter of Dakshin Dinajpur district is situated on the bank of Atrai River. The river is known for its traditional Raikar fish. Atrai drains into Brahmaputra in Bangladesh after passing by about 40 km across Dakshin Dinajpur district. Punarbhaba, known as Dhepa at its source, is the western channel of Atrai after bifurcation and flows in the southwest direction across Gangarampur town, the second largest town of Dakshin Dinajpur district. Punarbhaba joins Mahananda in Bangladesh after crossing about 40 km in Malda district in West Bengal.

1.1.1.8

Kulik–Nagar–Kalindi Subbasin

Mahananda has a number of tributaries like Kulik, Nagar, Gamar, Chiramati, Kalindi and Tangan rivers and all these tributaries flow in two districts of Malda and Uttar Dinajpur sometimes assuming as transboundary river between West Bengal and Bangladesh or occasionally as the boundary between West Bengal and Bihar. All the tributaries drain ultimately in Mahananda River. Among all these tributaries, Kulik, a small river, crosses Raiganj town of Uttar Dinajpur and after passing by a few kms with a crisscrossed pattern it meets Nagar in Raiganj Block of Uttar Dinajpur (Fig. 1.2). The combined flow takes the name of Nagar that joins Mahananda after a little distance from the confluence of Kulik and Nagar. Apart from Kulik and Nagar, other tributaries like Chiramati and Gamar traverse a few km in Uttar Dinajpur district and ultimately meets the combined flow of Nagar and Mahananda. Tangan, a major tributary of Mahananda originates in Bangladesh and after flowing a several km distances enters Malda district of West Bengal. Tangan River outfalls in Mahananda in the international boundary line of Bangladesh and India. River Kalindi rising from the foothills of the Himalaya flows through the Purnea district of Jharkhand and after flowing a meandering course of several kms meets Mahananda near Old Malda town of West Bengal.

1.2 Mahananda The river Mahananda rises from the Mahalidram Hills near Kurseong of North Bengal. From its mid-stretch, Mahananda flows with its two arms spreading in two states after its bifurcation into two channels—Phulhar flow and Barsoi flow. The Phulhar branch enters Jharkhand and the Barsoi branch flows through West Bengal. Mahananda River has a number of tributaries like Kulik, Nagar, Kalindi, Tangan, and Punarbhaba. Kulik joins Nagar near Raiganj of Uttar Dinajpur, and the combined flow joins Mahananda in the same block of Uttar Dinajpur after a few kms taking the name of Mahananda in its downstream. After the union with the other tributaries like

1.3 Damodar

9

Fig. 1.2 Confluence of Kulik (right) and Nagar (left) near Raiganj in Uttar Dinajpur district and both the rivers are connected with the temporary bamboo-made bridge during the lean period for easy movement of the locals

Kalindi, Tangan and Punarbhaba, Mahananda River drains into Ganga in Bangladesh after crossing the international boundary between India and Bangladesh.

1.3 Damodar Damodar River, once known as the sorrow of Bengal, originates in the Palamau Hills in Jharkhand. The river length is about 592 km from its source of origin to its confluence with Hooghly River at Garchumuk in Howrah district in West Bengal. The river crossed six districts viz. Manbhum, Hazaribagh, Paschim Bardhaman, Purba Bardhaman, Hooghly, and Howrah along its course. The river is divided into two channels at Baguhana and after its bifurcation, the main channel Mundeswari outfalls into Rupnarayan River sharing its major quantum of discharge from Damodar. The other one, namely Amta channel traverses almost all over the Howrah district in West Bengal. Panchet Dam, Durgapur Barrage and Atanna Gate (58 Sluice Gates) at Garchumuk have been constructed in the sixties of the last century and handed over to the Government of West Bengal to combat floods often occurring in the Damodar valley. Earlier the flood of river Damodar used to bring a kind of blessing when there were dense forests on both sides of this river [21]. The floodplains of the river were covered with silt due to the flood and produced abundant crops for several years. After the forest disappeared, dense human settlements developed. Now floods damage human settlements and cultivated crops in agricultural lands. By constructing dams and barrages it has been possible to control the flood of Damodar River from time to time.

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1 River Systems of West Bengal: Water Quality and Environment

1.4 Ajoy The Ajoy River is an important tributary of the river Bhagirathi. This river originates from a small hill near Deoghar in Jharkhand. It flows about 142 km in West Bengal out of its total length of 288 km from its origin to the confluence with Bhagirathi River near Katwa of Purba Bardhaman district. Ajoy has a number of tributaries, and the major tributaries are Kunnor, Jainti, Darua and Hinglow. The catchment area of this river is long and narrow and is about 5960 km2 in Bihar, Jharkhand, and West Bengal. Out of its vast catchment areas, the total catchment area in West Bengal is only about 2450 km2 . Renowned towns like Deoghar, Jamtara, Bolpur, and Katwa are situated on the bank of Ajoy River.

1.5 Rasulpur Rasulpur River is formed as a tidal river near Hooghly estuary after the contribution of discharge from its three tributaries Bagada, Sarpai, and Madhakhali. The river flows in the Contai subdivision of Purba Medinipur district that outfalls in the Hooghly estuary near Dariapur of Purba Medinipur district. The historic Kapalkundala temple is located at the confluence of Rasulpur and Hooghly rivers near Dariapur under Contai subdivision in Purba Medinipur.

1.6 Brahmaputra Basin The northern part of the state of West Bengal constitutes the Brahmaputra basin comprising its river systems. The Brahmaputra, a large basin, contains a total area of only 11,860 km2 in the state of West Bengal because the river Brahmaputra itself does not exist in West Bengal though its river systems flow within the state. Most of the river systems under Brahmaputra basin are characterized with their perpetual snow-line origins containing snow-bound catchments only except Jaldhaka River. These rivers, typically flashy in mountainous and sub-mountainous regions, cause devastating flood situations off and on particularly in the plains during monsoon period due to heavy rainfall in the hills. The total catchment areas of Brahmaputra comprising 11,860 km2 within the state of West Bengal is comparatively small in comparison to the catchment areas of Ganga basin which is about 73,833 km2 .

1.8 Raidak

11

1.6.1 Torsa–Kaljani Subbasin Torsa River, flowing through Tibet, Bhutan, West Bengal, and Bangladesh, originates at an altitude of 7065 m from Chumbi valley of South Tibet. Sil Torsa and Char Torsa are the main tributaries of river Torsa that originated after the bifurcation of the main channel below Hasimara area though both of the tributaries meet once again near the forest of Patlakhawa. Torsa flows across the Cooch Behar district headquarter and unites with Kaljani followed by Raidak-1 after a few km. The river along with the combined flow of Raidak-1 and Kaljani joins Brahmaputra at Nageswari in Rangpur district of Bangladesh.

1.7 Teesta The river Teesta begins to flow from the junction of the two rivers Lachen and Lachung at Chungthang in the glaciers of North Sikkim at an altitude of 6400 m. The river forms the boundary between the states of Sikkim and West Bengal at Rangpo and enters the state of West Bengal. Teesta River ultimately flows in the plains at Sevoke after crossing through the narrow gorges for several kms in the hilly areas. Teesta is known for its enriched history of Debi Chowdhurani who liked the water route of Teesta with her boat for her voyage from Rangpur (presently in Bangladesh) to Jalpaiguri and vice versa. The Teesta River systems, comprising its tributaries, has a catchment area of about 12,650 km2 up to its confluence with Brahmaputra at Rangpur district in Bangladesh.

1.8 Raidak The river Raidak of the Brahmaputra basin rises from Bhutan and flows into West Bengal after its bifurcation at India-Bhutan boundary area. The two streams Raidak1 and Raidak-2 joins other tributaries of the same systems after bifurcation where Raidak-1 meets the combined flow of Torsa-Kaljani and Raidak-2 joins Sankosh at downstream that ultimately unites with Brahmaputra River in Bangladesh taking the name of Gadadhar at Assam-West Bengal boundary.

12

1 River Systems of West Bengal: Water Quality and Environment

1.9 Jaldhaka The river Jaldhaka, a transboundary river flowing through Bhutan, Bangladesh, Sikkim, and West Bengal, originates from Bitang Lake in Sikkim at an altitude of 4400 m. Jaldhaka River joins the Dharala River after flowing through mountainous, sub-mountainous, and plain regions. The combined flow enters Bangladesh and meets the river Brahmaputra in the south direction downstream.

1.10 Sankosh The river Sankosh of Brahmaputra River systems (also known as Gadadhar at the confluence), a natural boundary between West Bengal and Assam originates in Bhutan. The river meets Brahmaputra in Bangladesh after its union with Raidak-2 taking the name of Gadadhar.

1.11 Subarnarekha Basin The river Subarnarekha outfalls into the Bay of Bengal directly and so, Surarnarekha is to be considered as a separate basin though it has a very small catchment area in the state of West Bengal. Subarnarekha River rises from the Chota Nagpur Hills of Jharkhand. The river drains about 13,950 km2 in Jharkhand, 2160 km2 in West Bengal and 3201 km2 in Odisha. Dulung is the only tributary of Subarnarekha in West Bengal though it has a number of tributaries like Kunchi and Kharkai in Jharkhand and Kakari in Odisha.

1.12 Rivers of Sunderbans About 33 rivers, creeks, and tidal inlets of Sundarbans are connected to everyone. Almost all the large and small, wide and narrow tidal courses of the Sundarbans flow parallel to the sea. One can easily travel from one river to another in this world-famous mangrove forest land. Two opposite currents are seen in the Sundarbans rivers during monsoon, which are swollen by tidal water rising from the sea [23]. Tidal currents from the Bay of Bengal flow from south to north but monsoon water flows from north to south. During the rainy season, when the wind starts blowing, the water in the river swells. The flow of water generated due to strong winds and current hits the river embankment and breaks it. In consequence, floods damage human settlements and land crops. It takes about 3–6 years for the salt water inundated area to return to normal. The rivers of the Sundarbans depend on the movement of tides. Here the ebb

1.13 Shifting of River Courses

13

tide lasts longer than the flood tide and the current velocity is very low in the rivers of the Sunderbans. As a result, the sediments carried by the tide start accumulating in the riverbed and floodplains. Rivers of Sundarbans find their way to meet the sea at confluence but sometimes it finds a way, sometimes it doesn’t [14]. These rivers are lost in the deposits of accreted soil [15]. Mangroves grow in the floodplains of the Sundarbans rivers. The tidal vegetation, adapted in the estuarine brackish water, copes with natural disasters in the Sundarbans region, and it maintains ecological balance [21]. Mangroves protect Sundarbans rivers from pollution by absorbing metals from urban sewage effluents [12, 13, 19].

1.13 Shifting of River Courses No one has recorded any past history of the shifting of the course of the rivers in the land of Bengal. There is no evidence that any continuous practice of the metamorphosis of the rivers in the Bengal Basin ever took place in the past. Several travelers, writers, and historians of the past, such as Pliny (116 AD), Ptolemy (150 AD), Fa-Hien (405–411 AD), Hiuen Tsang (640 AD), Barnier, Abul Fazal (1590 AD), and Buchanan Hamilton (1808 AD) described the various rivers of the country but did not record the behaviour of the shifting of the river courses. Apart from these historians, writers or travelers and some surveyors drew several maps showing the course of the rivers of the Gangetic Delta. Notable among these surveyors are Ptolemy (150 AD), Jao de Barros (1540 AD), Gastald (1561 AD), Caesar Frederick, Handi Ves (1614 AD), Mercator (1620 AD), Blaev (1690 AD), Van Den Brouke (1660 AD), Valentine (1670 AD), Cantelli da Vignola (1683 AD), Major Rennel (1764– 1777 AD), and Major Lang (1781 AD). Although the sketches or maps drawn by them showed the direction of the rivers flowing through the Bengal basin in the past, but the acceptability of these maps or sketches is questionable. Because the subject of cartography was not introduced in those days. Cartography, an advanced section of Geography particularly for the preparation of maps, became known in the nineteenth century. Moreover, the lack of modern equipment leaves doubts as to how scientifically the maps were drawn at that time. Therefore, due to faulty data and not being a perfect map, these maps or sketches could not accurately depict other important information including the shifting of the river courses. Among the many maps by such surveyors, Major Renell’s map is regarded as the first scientific map of the Bengal basin. Major Renell surveyed the entire Ganga–Brahmaputra delta from 1764 to 1777. A comparison of the rivers mentioned in Major Renell’s map with the rivers in the current map shows the changes in the river courses in West Bengal. A notable example of lateral migration of the river is the Teesta River which was probably once a tributary of the Ganges River as shown in the maps of Major James Reynold. But later on, the direction of the river flow changed and gradually shifted eastward due to neotectonics. As the Teesta River is situated on the tectonic plate like the shape of a whale back in North Bengal, in just 300 years, the Teesta moved eastward due to neotectonic movement, and it joins the Jamuna River in Bangladesh

14

1 River Systems of West Bengal: Water Quality and Environment

which is the current location of the Teesta River. The records in maps by Major James Reynolds for shifting of Teesta course towards the east was earlier supported by Milligan, a surveyor who surveyed in the floodplain of river Teesta in 1811 and Buchanan Hamilton who wrote about the changing of river course during his travel for the period from 1830 to 1833 across North Bengal. Apart from Teesta, the main artery of flow of Ganga and its major channel Bhagirathi-Hooghly have been changing the river courses with space and time. The Bhagirathi-Hooghly, the main course of flow of the river Ganga in West Bengal before the twelfth century was shifted to the east which is river Padma at present. Then the quantity of discharge was divided by Padma and Bhagirathi-Hooghly with a major share alternatively for some years for Padma and for some years for Bhagirathi–Hooghly during the period from twelfth to sixteenth century. The situation became dramatically changed from the sixteenth century from when Padma used to flow as main channel taking major share of discharge of the river Ganga deserting the other channel Bhagirathi-Hooghly as a mere spill channel that receives a portion of flow of the river Ganga only for a few months of a year particularly during the monsoon period. The Bhagirathi-Hooghly receives a huge quantum of discharge in its downstream stretch from its tributaries from both east and west sides [23]. Bhagirathi-Hooghly bears the name of a same river where Bhagirathi is named at its upstream stretch whereas the river is named Hooghly in its downstream stretch just after the confluence of Bhagirathi and Jalangi near Mayapur of Nadia district in West Bengal. Like the Teesta and Bhagirathi–Hooghly, there are evidence that the Damodar, Kangsabati, Rupnarayan, and other rivers have moved sideways indicating lateral migration many times in their floodplains over time.

1.14 River Commons The concept of river commons is very old although the concept has not yet known much till date. River commons are closely related to the daily life of the people living on both sides of the river. The riverside people of two villages from two opposite banks of a river generally come to capture fish from the same river and introduce them to each other, from which the social contact between the two families gradually begins. Again, from a long distance, the ferry boat from the upstream to the confluence of the rivers takes passengers from villages along the river course every day and before the afternoon, the ferry boat went back to its homeland on the way back upstream from the estuary. The interaction between boatmen and passengers during the ferry services has a great societal impact. The river, the river water, the river course, or the silver crops of the river belong to all, never to anyone. In a word, whatever river is used for the welfare of the common people is river commons. Since the river is public, all communities around the rivers, all common people including people associated with all professions get an opportunity to use it so that river can be used equally, and in such a nature-people monitoring of the government with the assistance of the members of the village bodies is very important in this regard. On the contrary,

1.15 Interbasin Transfer of Water Resources

15

residents living on the banks of the river should take care of the riverine environments so that the river cannot be used arbitrarily by the government or political parties. For example, local people should monitor the discharge of untreated sewage effluents into the river without treatment by the municipal officials of a municipality located on the banks of rivers. Not only river watersheds but riverside forests, pastures, historical sites etc. should be included in river commons. Rivers usable from different dimensions are common, so river commons are not measurable by any unit. The once rich forest along the banks of the river in the land of Bengal has disappeared, but thanks to the government forest department for the initiatives of the afforestation programme. The social forest is now a place for everyone to feast on the banks of the river, particularly during the winter. Rivers are common public resources, so their pollution is not desirable in any way. Moreover, rivers have no country or state-wise identity as most rivers have their source or confluence in different countries or states.

1.15 Interbasin Transfer of Water Resources The subbasin transfer of water resources for a variety of purposes has been a topic of debate in India since the nineties of the last century. The then Government of India proposed to interlink both fluvial and tidal channels of the river systems like Ganga, Brahmaputra, and Subarnarekha for the multipurpose uses like irrigation, power generation, control of flood, and specifically the transfer of surplus water into the rivers suffering from waterlessness. Usually, Brahmaputra River carries surplus water than that of Ganga and so, if both the rivers are interlinked, then the extra quantum of discharge into Ganga from Brahmaputra may be compensated as the river Brahmaputra has huge water resources. Thus, regional water imbalances may be removed by such interbasin transfer of water resources. The concept of interbasin transfer of water resources is not new to the state of West Bengal. For example, construction of Teesta Barrage in the Teesta subbasin and diversion of water thereon by excavation of Teesta Canal for agricultural purposes in and around Jalpaiguri district is the purpose of the project. The Teesta Canal is connected to the river system of Mahananda subbasin which is a great example of interbasin transfer of water resources from the Brahmaputra basin to Ganga basin via Mahananda subbasin. Another classic example of interlinking rivers is the Odisha Coast Canal which was excavated in the time span of 1870– 1880 during the British period where the Subarnarekha, Brahmani, Burhibullum, Rasulpur, Haldi, and Hooghly rivers are interlinked that serve several purposes like irrigation, flood control, recession of excess water from the agricultural land etc. during the harvesting time particularly in Contai subdivision of Purba Medinipur district. The Odisha Coast Canal depicting the interbasin transfer of water resources and its utilization and development is not an unknown aspect in the state of West Bengal. The Odisha Coast Canal, the interbasin link canal, not only provides water for irrigation in Contai subdivision but also served as an inland waterway to the inhabitants

16

1 River Systems of West Bengal: Water Quality and Environment

of Purba Medinipur district. Apart from the interlink canal or Teesta canal, the diversion of water movement from Ganga to Bhagirathi is another example of interlink water resources by the construction of Farakka Barrage for saving Kolkata Port that is lacking enough water for navigation in the downstream of Hooghly River. The reason for such diversion of water flow from Ganga to Bhagirathi-Hooghly River system is only due to the dearth of water in the lean period in the upstream that can drain to the downstream for the maintenance of the flow of the river. But Farakka alone cannot fulfill the requirements of quantum of discharge to keep up the navigability of the Kolkata Port due to the bipartite commitment related to water release between the two nations India and Bangladesh. Apart from the construction of dams, barrages or large sluice gates for diversion of waterways, the local socioeconomic conditions, ecological and environmental factors are to be exercised before implementation of such interbasin transfer of water resources. It is to be noted that interlink transfer of water resources never achieves a final shape as the river course of any river system under a river basin always tends to change its course. Again, the water requirements for irrigation, power generation, navigation, forestry, ecology and environment, and domestic purposes including other sectors in the state of West Bengal is about 10.85 MHaM (Million Hectare Meters) but the available utilizable water resources for the state is about 6.77 MHaM that shows the shortfall of water resources about 38% for the state of West Bengal. The shortfall of water resources must be rather a better picture of the basin wise water shortage in the state of West Bengal.

1.16 River Pollution West Bengal is known for its intricate pattern of river networks. The land of rivers West Bengal is characterized with the three principal river basins like Ganga, Brahmaputra, and Subarnarekha basins comprising numerous fluvial and tidal river networks that drain the state generally from the north to the south directions. The river basins of the river systems of West Bengal are mostly populated and the number of inhabitants has gradually been increasing in the riverside region which is generally enriched with biodiversity and dynamic ecosystems [5, 7]. As the riverside areas are befitted for the development of the industry, so most of the industries are established on the riverbanks, that results in enhancing the population surrounding the industrial belt. As a consequence, industrial wastewater effluent simultaneously with domestic sewage and solid wastes are received by the river released from the industries and human habitation zone. Surface water quality of the rivers deteriorated mainly for the industrial effluent, municipal and domestic wastewater discharge including discharge from the non-point sources. Industrial effluents are released from the 48 grossly polluting industries (GPI) and about 400 seriously polluting industries (SPI) in the state of West Bengal [3]. These industries usually release effluents after the treatment through effluent treatment plants (ETP) which are installed within the premises of these industries. The treated discharge is then drained either directly into rivers, lakes, tanks or ponds, or

1.17 Water Quality Rating

17

channelized to municipal sewer or wetlands through canals. Apart from the industrial effluents or municipal wastewater, the riverside habitation and their activities drain a huge amount of solid waste materials in the river as runoffs during the rainy season on a regular basis [6]. Such runoff discharge, generally the solid wastes dumped on the riverside habitation, are added from the non-point sources [9]. Declining determinants for river pollution generally become heavily concentrated in the nonperennial rivers during pre-monsoon and post-monsoon time i.e., during lean period. In addition to the pollutants from the non-point sources, runoffs from the cultivating lands mix with the river water either directly or channelized through canals though the pollutants from non-point sources and that of the agricultural runoffs from the farming land are not considered as the agents of river water pollution by the West Bengal Pollution Control Board in their consecutive reports whenever they are published. The stretches of 17 (seventeen) rivers in West Bengal are identified as polluted in the report of Central Pollution Control Board published in 2018 which is reduced to 13 (thirteen) in the report published by the same organizations recently in 2022 [4]. Though the number of rivers stretches reduced to 13 from 17 in the CPCB Report 2022, the length of the polluted stretches of some rivers like Rupnarayan increased in comparison to the CPCB Report 2018 (Table 1.2). The polluted river stretches are categorized with five priority classes like Priority I, II, III, IV, and V based on the concentration of the biochemical oxygen demand obtained from the analysis. The West Bengal Pollution Control Board is directed by the National Green Tribunal to monitor the water of such river stretches by installing effluent treatment plants by which the water quality should be good changing the values of biochemical oxygen demand less than 3 mg/l and number of faecal coliform bacteria less than 500 MPN/ 100 ml of surface water samples which will standardize river water at least for outdoor bathing [2, 24].

1.17 Water Quality Rating Uses and utilization of river waters are generally determined by some selected physicochemical and biological parameters like pH, conductivity, DO, BOD, COD, TDS, TSS. TFS, TA, TH, calcium, magnesium, faecal coliform bacteria etc., and water quality index are computed averaging weight of some of the selected water parameters like pH, conductivity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, total fixed solids, total alkalinity, and total hardness according to their significance and importance in a particular environment [25]. In the present study, water quality index (WQI) is calculated using the standard statistical formula considering the minimum and maximum values of individual physicochemical parameters of the rivers in the state of West Bengal based on Database on environment and forestry statistics of West Bengal [1]. After computation of water quality index, water quality rating is graded using the obtained values of WQI (Table 1.3). The water quality rating shows that the river water of Bidyadhari of the Sunderbans are extremely poor because domestic

18

1 River Systems of West Bengal: Water Quality and Environment

Table 1.2 Comparative studies on the polluted stretches of the rivers in West Bengal Sl. Name of the Rivers No.

2018 Polluted stretch

BOD (mg/l)

1

Churni

Majdia to Ranaghat

10.3–11.3 III

2

Jalangi

Laldighi to 8.3 Krishnanagar

IV

Along 6.2 Krishnanagar

IV

3

Mathabhanga

Madhupur to 8.5 Gobindapur

IV

Along Gobindapur

15.3

III

4

Bhagirathi–Hooghly Tribeni to Diamond Harbour

5–12.2

III

Baharampur to Haldia

8.0

IV

5

Rupnarayan

Kolaghat to Benapur

3.1–5.8

V

Kolaghat to Geonkhali

3.7

V

6

Dwarakeswar

Bankura to Kushtia

1–5.6

V

Along Bankura town

3.8

V

7

Barakar

Kulti to Asansol

5.7

V

Along Asansol

3.1

V

8

Dwarka

Tarapith to Sadhak Bamdeb Ghat

5.6–17

III

Along Tarapith

5.7

V

9

Kangsabati

Midnapur to Ramnagar

9.9

IV

Along Midnapore

6.3

IV

10

Mahananda

Siliguri to Binnaguri

6.5–25

II

Along Siliguri

31.0

I

11

Damodar

Durgachak to 4.4–8.2 Dishergarh

IV

Dishergarh to 5.2 Bardhaman

V

12

Teesta

Siliguri to Paharpur

3.3

V

Along Sevoke

3.8

V

13

Bidyadhari

Haroa to Malancha

26.7–45

I

Haroa to Malancha

29.6

II

14

Karola

Jalpaiguri to Thakurer Kamat

3.9

V

15

Kaljani

Bitala to Alipur Duar

6.0

V

16

Mayurakshi

Suri to Durgapur

5.2

V

17

Silabati

Ghatal to 3.8 Nischindipur

V

Modified after CPCB Report [4]

2022 Priority Polluted stretch Bijoypur to Ranaghat

BOD Priority (mg/ l) 20.8

II

1.18 Abandoned Channel

19

sewage canals from the Kolkata megacity drains all the wastewater into the river along with the industrial effluents from East Kolkata [8]. So, the Bidyadhari River water is completely unusable along its entire tidal stretch from Haroa to Dhamakhali in the district of North 24 Parganas under Sunderbans region. Apart from Bidyadhari River, the water of downstream stretch of Rupnarayan from Kolaghat to Geonkhali is in extremely poor conditions for high values/concentrations of total dissolved solids, electrical conductivity, and total alkalinity in the river water samples due to mixing of industrial effluents of Kolaghat and Haldia industrial belt [10]. River water of Churni becomes unusable for 5 to 6 times a year from its source to confluence due to release of wastewater effluents into Mathabhanga River from the sugar manufacturing factory standing at Darshana in Bangladesh without any treatment which ultimately mix with the river water of Churni. Churni originates from Mathabhanga River at Majdia in Nadia district of West Bengal. In the context of river pollution, the water condition of Damodar River is relatively fair. Although there are many heavy industrial areas on the banks of the Damodar River, the effluents of the factories are first treated and then released into the river water. So, the water of Damodar River is still now usable for agriculture and industry. Due to taking appropriate measures, the Shilabati flowing through Ghatal municipality has been exempted from the list of polluted rivers published in the Central Pollution Control Board (CPCB) Report 2022. Along with the Shilabati River, three other rivers that have been excluded by the CPCB in 2022 as polluted rivers and they are Karola of Jalpaiguri, Kaljani of Alipurduar and Mayurakshi of Birbhum [4].

1.18 Abandoned Channel Due to the sudden change in land slope and increase in river load due to coming from mountain stream to relatively flat land, in the middle and lower reaches of the river, the accretional work increases as compared to erosion work of the river. That is why accretional landforms tend to form in the middle and lower stretches of the river. In the middle and lower reaches, the river velocity is reduced due to the reduction in land mass. The course of the river becomes extremely meandering as a result of continuous erosion of the outer slopes and excessive accumulation of the inner slopes. Consequently, the river flows in a meander shape. When two such bends of a river come too close together and the narrow land between the bends erodes, the two bends merge. As a result, the river no longer follows the bends and starts flowing straight. Over time, sand, mud and silt accumulated on both sides of the abandoned bend and became separated from the main river. The course of that abandoned river creates the lake. Almost all the rivers in West Bengal have more or less lakes which are formed from abandoned river channels. Such geographical changes of the river course and the formation of lakes also have some historical facts with the perspective of societal scenarios with space and time.

Jalpaiguri

Alipurduar

Siliguri

Karola

Kaljani

Mahananda

Gobindapur

Krishnanagar

Jalangi

Ranaghat

Majdia

Mathabhanga

Churni

Siliguri

Teesta

Ramghat

Sampling Station

Name of the Rivers

38.35 40.77

2014–15

63.03

2013–14

66.04

2014–15

57.41

2014–15 2013–14

65.29

60.06

2014–15 2013–14

53.41

34.73

2013–14

42.9

2014–15

32.71

2014–15 2013–14

39.59

39.22

2014–15 2013–14

36.38

34.04

2013–14

29.13

2014–15

19.5

2013–14

21.12

58.07

58.35

74.33

83.85

80.62

74.24

73.37

73.34

69.84

86.79

41.51

38.75

33.81

33.53

36.95

27.58

29.93

25.45

28.92

31.33

32.16

37.16

31.11

37.13

30.92

31

26.35

28.53

25.21

27.58

28.32

26.18

18.11

16.33

17.29

16.42

Min

2014–15

Monsoon

Min

Max

Pre-monsoon

2013–14

Year

Table 1.3 Computation of Water Quality Index (WQI) for water quality rating of the river waters of West Bengal

48.07

39.37

74.42

62.59

69.14

64.18

54.5

58.46

46.87

63.28

45.89

48.14

32.26

193.52

21.58

21.69

31.1

74.1

Max

35.81

33.4

60.6

34

61.92

34.75

60.45

43.89

45.13

31.23

34.49

40.35

34.72

30.49

28.14

23.43

21.5

21.93

Min

(continued)

67.31

57.21

74.27

71.26

75.32

76.19

73.47

72.74

66.51

51.79

32.72

30.8

33.28

32.41

30.37

26.22

24.99

22.63

Max

Post-monsoon

20 1 River Systems of West Bengal: Water Quality and Environment

Ghatal

Gandhi Ghat, Midnapore

Kolaghat

Shilabati

Kangsabati

Rupnarayan

Satighat, Tarapith

Dwaraka

Damodar

Asansol

Barakar

Durgapur

Andal

Sadhak Bamdeb Ghat, Tarapith

Suri

Mayurakshi

Geonkhali

Sampling Station

Name of the Rivers

Table 1.3 (continued)

–

53.02

2014–15 2013–14

–

38.15

2013–14

38.36

2014–15

38.24

2014–15 2013–14

35.01

44.12

2014–15 2013–14

43.36

33.65

2013–14

36.32

2014–15

60.22

2014–15 2013–14

110.39

54.16

2014–15 2013–14

88.28

45.49

2013–14

36.02

2014–15

40.42

2013–14

42.2

–

60.12

–

114.18

81.11

83.78

67.08

47.06

45.98

40.93

41.14

289.99

242.59

92.24

161.73

55.36

54.81

64.16

39.41

–

45.74

–

32.36

30.53

28.08

31.35

30.59

32.98

28.27

28.35

52.48

44.26

33.84

40.41

43.24

23.37

22.22

8.74

Min

2014–15

Monsoon

Min

Max

Pre-monsoon

2013–14

Year

–

50.52

–

41.56

53.84

37.45

90.1

44.9

52.71

33.52

35.99

204.07

118.85

98.78

65.52

62.77

44.88

46.37

38.87

Max

50.38

45.53

51.02

53.95

31.62

50.68

47.87

42.29

39.6

32.24

25.87

44.72

51.67

29.11

42.33

35.12

30.91

34.73

28.4

Min

(continued)

60.18

72.08

65.81

108.94

50.94

59.53

49.04

46.5

43.58

38.28

28.79

90.81

82.98

89.63

59.21

58.09

57.91

41.64

37.33

Max

Post-monsoon

1.18 Abandoned Channel 21

Malancha

Haroa

Diamond Harbour

Dakshineswar

Serampore

Baharampur

Raniganj

Sampling Station

811.13 632.07

2014–15

307.78

2013–14

260.16

2014–15

166.42

2014–15 2013–14

150.71

70.36

2014–15 2013–14

70.25

71.89

2013–14

64.45

2014–15

67.97

2014–15 2013–14

63.98

54.55

2014–15 2013–14

–

1980.7

2062.4

739.32

514.45

501.65

499.78

96.93

80.51

76.68

81.01

77.54

80.49

65.45

–

60.55

242.87

100.61

200.38

76.53

74.97

56.28

43.26

23.05

40.87

44.16

44.98

43.26

34.78

–

35.34

Min

54.26

Monsoon

Min

Max

Pre-monsoon

2013–14

2014–15

Year

Water Quality Rating: WQI: 0–45 = Good; 45–60 = Fair; > 60 = Poor

Bidyadhari

Bhagirathi-Hooghly

Name of the Rivers

Table 1.3 (continued)

1558.3

665.5

507.61

270.82

107.32

144.97

51.63

64.99

59.1

67.82

59.97

61.82

83.82

–

46

Max

267.24

66.77

273.84

88.82

48.48

73.75

56.48

56.13

50.92

51.02

54.71

49.4

54.85

52.63

57.93

Min

481.9

228.73

310.79

106.75

175.53

95.28

74.82

77.14

8 1.91

79.54

76.31

73.29

67.19

67.53

72.59

Max

Post-monsoon

22 1 River Systems of West Bengal: Water Quality and Environment

1.18 Abandoned Channel

23

1.18.1 Kal Dighi and Dhal Dighi Kal Dighi and Dhal Dighi are the abandoned channels of the Punarbhava River on whose banks a rich history of thousands of years awaits [20]. The tale of two lakes, to be described, bears a little or no relation to poetic beauty, or luscious landscapes surrounding them. The lakes, Kaldighi and Dhaldighi presently at Gangarampur under Dakshin Dinajpur never inspired any poet, painter or novelist as stimulator for their creativity, write-up or romanticism. The lakes are simply ordinary in landscape beauty, neither surrounded by the enchanted woods and exotic land that enthrall nature-lovers, but the lakes and their surrounding areas are enriched with the history of ancient times. It’s a mythically known area recognized as Bangarh in the past. The belief of the people on the archaeological site of King Ban and his sovereign at Bangarh is making popular the name of the lakes Kaldighi and Dhaldighi, which are known for centuries. Mythologically it is said that the lakes, excavated by King Ban after the name of his two queens of black (kal) and fair (dhal) complexion, is a popular misconception as survey proves that the lakes are the paleochannel of Punarbhaba River. The munificence of King Ban and his kingdom Bangarh is only a myth, though the name of the place Bangarh exists till date. History does not support the existence of any king in the name of King Ban or the existence of his two queens. Nevertheless, the myth of King Ban and his two queens remains a top tourist attraction in and around the two lakes. Bangarh, stood nearby Punarbhaba River and the two lakes, is a historical place of interest, not for King Ban, but for the once ruling dynasty of the Mourya, Gupta and Pala kings as evidenced by the coins and clay pots which are found available during excavation of the surrounding areas of Bangarh ruined relics organized by the University of Calcutta. The area covering the two lakes is known as Devkot in the pages of history. Devkot, standing by the side of two lakes, was once a landmark of the first establishment of the Muslim dynasty in the soil of Bengal when this place was attacked and captured by Bakhtiyar Khiljee, the Turkish hero, during the first decade of the thirteenth century. The two lakes were then under the rule of Devkot kings. Beside Dhaldighi, a worldfamous Buddhist college namely Devkot Mahavihara was established by one of the kings of the Pala dynasty which is known at present as Dargaha of Aata Shah. Though Devkot Mahavihara once was converted into a Madrasha-cum mosque first, and then a Dargaha, a mosque erected by or on the grave of a certain Mohammedan saint, Aata Shah, it was once a landmark of Buddhist culture where Atish Dipankar Sreegyan was educated. Atish Dipankar Srigyyan, a renowned Buddhist scholar admired most the Devkot Mahavihara where he took his higher education. He used to recite the hymns of the Buddha epic Tripitaka sitting in the Mahavihara beside Dhaldighi, an abandoned channel of the Punarbhaba River. There was another lake nearby named Kaldighi perhaps with the same origin as Dhaldighi. Atish Dipankar Srigyyan wandered in and around the temple-town Bangarh in his leisure time accompanied by other classmates or students of that Mahavihara. He was the worthy student of the teachers like Adwaya-bojro, Udhilipa, Bhikshuni Mekhla and others who taught in this famous Buddhist college of Devkot Mahavihara. The Devkot Mahavihara-turned

24

1 River Systems of West Bengal: Water Quality and Environment

Dargah of Aata Shah is at present restored and preserved by the Archaeological Survey of India as it is a historical place of interest. Though the lake-view of the Dargah of Aata Shah is really nice having a stone-built landing place in the lake bank. The lake area of Dhaldighi has not been renovated yet either by the government or by any private sector. It is happy to see that the past scenario of the other lake, Kaldighi is now being renovated by the government and a Zilla Parishad Bungalow has been erected where both fooding and lodging are available for the interested and inspired tourists. The entire area covering two lakes having a rich history of ancient times is inspired to be believed to be a heritage site and should be restored as the same which attracts more tourists in the near future.

1.19 Riverine Civilization There were various reasons behind the development of riverine civilization in different parts of the world in ancient times, such as, fertile agricultural land, irrigation facilities, livestock rearing facilities, goods transportation and communication facilities, fishing, greater security, favourable climate, and drinking water facilities. Among these several factors, the most important is agriculture and abundant crop production in the fertile lands along the river basin. People living on the riverside region observed that when rivers overflowed their banks as a result of flooding, river alluvium was deposited around the basin when floodwaters spread into the areas. These alluvial soils are very fertile and relatively high in crop production. It is for this reason that prosperous habitation including townships developed on the banks of the Kulik and Nagar rivers in Uttar Dinajpur district where the fragrant Tulaipanji paddy was grown in abundance. Tulaipanji rice is still grown in the Kulik and Nagar basins and Uttar Dinajpur is the only district from which Tulaipanji rice is exported.

1.19.1 Tulaipanji—A Brand Produce from Kulik-Nagar Valley Tulaipanji rice is famous all over the world because it is very delicious, and its fragrance is incomparable [18]. For this reason, Ikhtiyar Uddin Mohammad Bin Bakhtiyar Khilji perhaps stopped his force of invasion at the bank of river Kulik after taking a dish of flavoured Tulaipanji rice including delicious preparation of Bou, Piyali, Chapla and Ghaira fishes caught in the waters of the Kulik. The flavour and quality of Tulaipanji rice feels soft like cotton (tula) at the time when that rice is eaten up. Tulaipanji is the softest one and most flavoured rice among 64 varieties of rice available in the district of Uttar Dinajpur. Tulaipanji rice yield is not good in relatively old parts of this district where soil type is ‘Khiar’ or ‘Khar’, old enough in origin

1.20 Summary

25

and much stiffer in characteristics containing heavy clay materials. On the contrary, Tulaipanji is grown well in the ‘Pali’, a light sandy loam type of soil that produces all description. The northern part of Uttar Dinajpur district is covered with such Pali soil and produce Tulaipanji in the villages of Radhikapur, Raiganj, Gouripur, Deogaon, Dalimgaon under Kaliaganj PS, Bangalbari under Hemtabad PS, Baliadangi, Kamalabari, Mahiniganj, Maharaja under Raiganj PS, Patiraj, Bhadrashila under Itahar PS in Uttar Dinajpur. The delicious, flavoured rice Tulaipanji is named after the Tulai River as the farmers and landholders start cultivating Tulaipanji at the Basin of Tulai River. Tulai River is now entirely silted up and converted into agricultural land. Another opinion lies with the nomenclature that the rice is denominated after Tulai Thakur, a local deity of Dinajpur district for hundreds of years. But somebody would consider that the cluster (punja > panji) of boiled rice looks like cotton (tula) that has cottoned up our mind for the exact source of origin of the name of Tulaipanji. In fact, Tulaipanjee rice is now available in the marketplaces of Dhonkoil, Durgapur, Patiraj, Dalimgaon, Maharaja, Mahiniganj, Raskhoa etc. in huge quantity at the rate of 3–4 hundred quintals in the season and up to 90 quintals during off-season. The area for the cultivation of Tulaipanji has gradually been decreasing due to lack of proper export of this well-known rice. Tulaipanji rice has not been eaten up by the farmers themselves as the soft rice is easily digestible before time and the farmers are then starving for the rest of the period of the day working in the field. Agricultural fields in and around Kulik Basin is considered to be suitable land for the cultivation of Tulaipanji. Rice and fish as food items in the dishes of lunch or dinner are simply delicious to any Bengalee living at any part of the world. Water of the river Kulik and its basin provide both world-class flavoured rice and fishes like Bou, Piyali, Chapla and Ghaira which are the most delicious indigenous fishes born in the river waters of Kulik only. Curry of those fishes including rice like Tulaipanji is simply heavenly. Only the Bengalee of all over the world knows that the Tulaipanji rice is so delicious to be eaten up, but no step has yet been taken up for its distribution for sale either by the Government or by any private concern even in the other districts of West Bengal in this era of globalization. There is no outlet for Tulaipanji rice in the Kolkata metropolis area, although Dehradun rice, Banskathi or Gobindobhog are available in every nook and corner of the marketplace in almost all the wards of the corporation area. If the flavour of flavourus Tulaipanji is spread with wide display and advertisement far and wide, that flavour spread happiness in the huts of the farmers of Uttar Dinajpur, although too much flavouring might spoil the preparation.

1.20 Summary Successful distribution of water for irrigation is possible by building dams and digging canals between the rivers of the basins like Brahmaputra Basin, Ganga Basin and Subarnarekha Basin in West Bengal. The Teesta Canal provides the waters from

26

1 River Systems of West Bengal: Water Quality and Environment

the Teesta River in the Brahmaputra Basin to the Mahananda River in the Ganges Basin and thus the use of water for various purposes like irrigation, power generation etc. through interbasin transfer of water resources has been successful in this state. Odisha Coast Canal is another example of interbasin transfer of water resources where it connects Subarnarekha basin to the Ganga Basin interlinking Brahmani, Burhibullum, Subarnarekha, Rasulpur, Haldi, and Hooghly rivers. The water condition of most of the rivers in these basins is not good [22]. But gradually the number of polluted river stretches is decreasing. As a result of government intervention, the number of polluted rivers stretches in the state of West Bengal is 13 in 2022, which was 17 in 2018. The water condition remains good if the factories standing riversides treat the effluents properly before discharge into the rivers.

References 1. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 2. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 3. Chattopadhyay B, Datta S, Chatterjee A, Mukhopadhyay SK (2001) The environmental impact of waste chromium of tannery agglomerates in the east Calcutta wetland ecosystem. J Soc Leather Tech Chem 84:94–100 4. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi, 110032, p 94 5. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 6. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 7. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 8. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 9. Das GK, Datta S, Sanyal SK (2004) Need for Geomorphic mapping in terms of physicochemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 10. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 11. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9 12. Das GK (2011) Impact of salinity and nutrients on the changing mangrove floristic—a case study from the river flood plains of Sunderbans, India (119–129). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 13. Das GK (2011) Studies on the potentiality of medicinal applications of some mangroves of Sunderbans (68–73). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408

References

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14. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 15. Das GK (2014) Environmental scenario of Sunderbans: planning and management (1–24). In: Anthropecology and applied biodiversity. OmniScriptum GmbH & Co. KG, Saarbrucken, Germany, p 408 16. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN 978-3-319-11342-5 17. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN 978-3-319-44190-0 18. Das GK (2018) Tulaipanjee—a brand-name of Uttar Dinajpur. Frontier 19. Das GK (2019) Medicinal plants around wetlands in Sunderbans. Frontier 1–3 20. Das GK (2019) A tale of two lakes. Frontier 1–2 21. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/. https://doi.org/10.1007/978-3-030-807 06-1 22. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 23. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 24. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 25. Ewing GN (1985) Instrumental method of chemical analysis. McGraw Hill Book Company, New York, p 624. ISBN 978-0070198517

Chapter 2

Shilabati River and Its Environments

Abstract The mixing of huge quantities of eroded materials from the upstream and middle stretches deteriorates the water quality of Shilabati River downstream. Along with such huge sediment load, discharge of untreated wastewater from both point and nonpoint sources results in the water of Shilabati River being unusable. Though water quality rating shows water in good conditions after calculation of water quality index still the river water is not to be prescribed for drinking, outdoor bathing, or other domestic purposes as the faecal coliform bacterial count shows their number higher than the permissible limit as standardized by the Central Pollution Control Board. Apart from the water conditions, Shilabati River is known for its geographical diversity and historical importance. Keywords Water quality index · pH · Suspended solids · Water hardness · Gangani · Chuar rebellion

2.1 Shilabati River Course Shilabati or Shilai is a small river in southwestern West Bengal. Shilai flows over Purulia, Bankura and Paschim Medinipur districts. Originating near the town of Puncha in Purulia, the river flows through deep forests and enters Bankura [13]. The main tributary of Shilai is Jayapanda that joins Shilai at Bankura including several other small tributaries. Then it flows southeast through Simlapal and enters Paschim Medinipur district. The main tributaries of Shilai in Paschim Medinipur are Kulbai, Tamal and Parang. Among them, the Kulbai or Kubai River originates near Tangosol and crosses the Medinipur-Bankura railway line to join the Tamal River near Mugbasan and the confluence flows into the Shilai River near Narajol. But there is no water in the Shilai River or its tributaries at their sources except during the rainy season. Flowing through Garbeta and Kharkusma in Paschim Medinipur, Shilai joins the Dwarkeshwar River at Bandar-Pratappur near Ghatal. Ghatal is the only municipal town and an important commercial center located on the banks of

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Shilai river. Shilabati River is included in Damodar basin and the river water is polluted in the 3.8 km downstream river stretch from Ghatal to Nischindipur [14]. Although it is a narrow stream for several miles from the source, the Shilabati River is relatively wide in the middle stretch. In the middle stream of Shilabati, Gangani is the famous Grand Canyon of Bengal on the riverbank near Garbeta where many students come for research in the field of geography and environmental sciences. The forest surrounding the Gangani plain is the place known for the history of the century old Chuar Rebellion. Along with such enriched history and geography, the myths and tales of Gangani are nice to hear from the local people. The rich history, mythology, and geography surrounding Shilabati and above all the qualities and characteristics of the river water is the focus of study in the field of water quality and environmental research.

2.2 Myths and Local Belief The people of the district (Purulia), the place of origin of Shilabati River, think that the river also has a birthday, and they celebrate that birthday every year on the day of Poush Sankranti. On this occasion, a fair is held near Baragram in Hura, at the source of the river Shilabati. It is a three-day fair. But the broken fair remained for about a week. There is a pond near Baragram village on the Puncha–Purulia road which is the venue of that fair held every year. The Shilabati River is believed to start from there. As per the local belief, the river Shilabati is the daughter of every family in this region. According to folk belief, in the village where Shilabati originates, a holy man lived in a cottage, his name was Jaya Panda, and his disciple Shilabati lived with him. Once the holy man decided to go on a pilgrimage to the confluence of the Ganges at Ganga Sagar. On hearing the holy man’s wishes, Shilabati, his disciple, was willing to go to the pilgrimage site, but the holy man was reluctant, because there is danger of thieves, robbers, tigers, wolves, and jackals on the way. Then his disciple Shilabati hands over a package to the holy man and says that by throwing this package into the water of Ganga Sagar confluence, his pilgrimage will be completed. The holy man saved himself from many dangers along his journey with that package, from the paws of tigers, or from the sticks of robbers. Now when he reached the pilgrimage place and threw the package into the water of Ganga Sagar, just then two hands came up from the water and took the package and disappeared again under the water. The holy man was surprised and came back to his shelter in seven haste. When he returned to the cottage, he saw that his disciple Shilabati was coming towards the cottage with a pitcher full of water. Seeing the holy man, Shilabati dropped the pitcher full of water and ran in the opposite direction, and the water of the broken pitcher created a river named Shilabati. But the holy man did not give up on the flow of Shilabati, he ran and caught his disciple Shilabati some distance away from Garbeta, and his desire was fulfilled, and ultimately the holy man and his disciple united. Thus, the Jaya Panda tributary joins the Shilabati River. Since then, Shilabati is the daughter of every family from Puncha to Hura region in Rarha Bengal. Shilabati is a beautiful

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small river. At the end of her journey, Rupnarayan is born from the union of the Dwarakeswar River with the beautiful Shilabati shining in form. Around this saying, a fair gathers every year by the river. There is also a committee to manage the fair. And a temple is erected in the name of Goddess Shilabati adjacent to a pond in the square. Boats operate there during the fair. There are street vendors, and all kinds of shops. Many come to the temple and pass the clay idol of Goddess Shilabati [14].

2.3 Environmental Scenario Sometimes people’s actions upset Shilabati who is like a daughter of the local residents because the navigability of the river decreases at normal speed. But the role of people is no less to block the path of any flow. The stream is dying for them. Bengal is known for its river civilization. The importance of the river becomes clear to all. The river with which the folklore is intertwined is no less important. People thought about the river because of its importance in public life. Rumour has been created. But if the river is gradually polluted, then get upset but many people do not understand the impending danger. Shilabati is one such important river. All over the country there is a study going on about river pollution. Because freshwater reserves are decreasing gradually. But no such organizations or environmental activists have started working on Shilabati in Paschim Medinipur. The government administration does not take care of managing the river environment. In Shilabati, thermocol plates and bowls are sometimes seen floating. During the festive season, flocks of plastic-thermocol plates get stuck on bamboo poles above the river. Locals pushed the garbage with bamboo to save the wooden bridge of indigenous materials. Again, they floated in the river water. And this is a familiar sight on the Shilabati River. Shilabati has been used in many ways for a long time. There are no large-scale factories in the region except a few small-scale like insane stick and battery manufacturing units. Naturally, the factory waste does not pollute the river. But settlement has made up for that deficiency. Pollution spreads from the piles of garbage dumped on the banks of the river. During the collection of various resources of the river, including sand, the riverbed is being cut unscientifically. It is putting pressure on the bank. If anyone looks along the banks of the river, he will see signs of such atrocities in the basin of Shilabati. Ghatal municipality officials and public representatives agree about the pollution, including the Irrigation Department too. But no steps have been taken yet to prevent pollution. But the river must be freed from man-made pollution. The river gets polluted from the waste left by the tourists and the picnic parties at Gangani in the middle stretch of the Shilabati River. Gangani is a geographically important historical place for tourism.

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2.3.1 Gangani Gangani is located on the banks of river Shilabati and is famous locally as the Grand Canyon of Bengal. Gangani is very close to Garbeta in Paschim Medinipur district. Local people believe that a battle took place here looking at the features of all the different landforms in the slopes and plains of Gangani, which belongs to mythology. Characters like Bakasura and Bhim of the Mahabharata are behind the myth told by the local people. They believe that Bakasura used to live in a huge cave in Gangani. At that time, the demon Bakasura was very powerful in and around Gangani and a whole person was chewed by Bakasura every day for his lunch as per the pact between the demon and the villagers in and around Shilabati river basin. On such a happy day of Bakasura, the Pandavas all arrived together around Gangani. The Pandavas were then in anonymity, so they took refuge in a Brahmin family at Bhikhnagar in the left bank of Shilabati River and opposite to Gangani as Brahmins in disguise. One day the time came for the Brahmin family in which the Pandavas were sheltered when one of the members of the family had to go to be eaten by Bakasura. From the sound of crying in that family, the Pandavas came to know about the daily routine of Bakasura’s midday meal. After knowing the facts about the lunch schedule of the demon, Mother Kunti directed Bhima, the second Pandava to go and face Bakasura at his cave and there was a fierce battle between them. Bakasura was defeated and killed in this battle. But under the force of war, the 30-m-high hill of Gangani and its plains got twisted. As a result, Gangani’s plain is high and low, messy, and uneven. This myth is told by local people across Gangani. The scientific reason for the landform variation of Gangani is however different. The ground water level fluctuates due to the huge rain in monsoon time and dry river condition during the rest of the year resulting in fluctuating humidity and dryness. As a result, laterite is formed. Rainfall, temperature, wind speed etc. continued working on laterite erosion for the period from 2 million to 10,000 years BP. First the erosion creates micro- to small canals, and then the canals join each other to form gullies. Gulli is one type of evidence of land erosion. This canal and gully together form the present topography of Gangani which is locally known as the Grand Canyon of Bengal [14]. Erosion on the 30 m long slope of Gangani has created various structural variations like the shape of pagoda, temple, pyramid, wild buffalo, and even a shape of human beings coloured with various stains like red, grey, white etc. All in all, Shilabati’s geological manipulation, Gangani, is developed on the whims of nature (Fig. 2.1). Apart from folklore and mythology, the landscape of Gangani on the banks of river Shilabati attracts tourists. Not only the topography of Gangani, but also the history of several rebellions spread throughout its thick forests which in modern history is known as Chuar Rebellion. Of late, almost everyone remembers a tragic history of betrayal and wound of Chuar Rebellion in Gangani field. The British forces could not capture Achal Singh, the leader of the Chuar rebellion, despite ravaging the Sal and Piyal jungle with thousands of cannon shots, but Chhatra Singh, the last king of Bagri, ascended the throne after handing him over to the rulers of British India.

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Fig. 2.1 Shilabati River at Gangani near Garbeta of Paschim Medinipur district

The British forces caught Achal Singh and his companions red-handed and, without waiting for trial, hanged them in the Gangani field in front of the local people. Not the sighs of the leader of the Chuar Rebellion and his companions, but the jagged peaks of the gorges of the Gangani plains on the banks of the Shilabati, from peak to peak, become intensely coloured in the sun with the anger of the rebellions. Gangani is rich in such a modern history. Today, hundreds of tourists visit Gangani to witness the breathtaking geography, modern history, and mythology.

2.4 Riverine Environment Shilabati originates from Purulia. There is a legend about the origin of the river that shows its importance. A woman named Shilabati took refuge with a Brahmin. According to legend, this Shilabati is named after him. In its downstream stretch, a trading center was once built around the river. Shilabati is closely involved in the naming of Ghatal. Once a steamer used to run in Ghatal town. The elders of Ghatal still tell the story of steamer voyage to their grandchildren. Shilabati is now under the influence of pollution. And gradually it is losing its luster. Pollution of the river Shilabati is not a problem today. However, pollution has been visible for three-four decades. The navigability of the river has decreased a long time ago. As a result, water transport has stopped. But the silt was not removed and reformed. Flooding is a major problem every year as the river reduces its storage

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capacity. Apart from this, the water of various rivers, canals and ponds meet in Shilabati. This water also carries various garbage. Shilabati is also filling up. But it is also having a great impact on the ecosystem of the river. Once upon a time, hilsa and shrimp were found in the river Shilabati. Many people made a living by catching fish. But the navigability of the river reduces, the pollution increases, and the number of fish has decreased. Naturally, the number of fishermen has decreased. And if such a situation continues, the ecosystem of the river will be destroyed. Then it will affect the cities and villages standing along the river. Due to the navigability crisis, various waste materials are accumulating at the bottom of the river. It causes great loss of biodiversity. One of the reasons for the pollution of the Shilabati is the garbage left on the banks of the river. Ghatal town has a more sinister appearance compared to the parts flowing in the countryside. A part of the riverbank of Ghatal city is full of garbage. Many knowingly and many others have made the riverside a permanent destination for littering. Day after day, for years, piles of garbage have been accumulating on the banks of the river like this. This garbage is directly mixed with the river water as runoff during the monsoon [9]. Then the riverbank becomes empty. After a few days, the riverbank was again covered with garbage. They again go back and fall into the river water. The regret of the people living in Rajnagar on the banks of the river, the current state of Shilabati seems to be not a river, it is like a dustbin. Dumping garbage on both sides of the river has become a habit in Ghatal town. Garbage from hotels and restaurants is mixed in the river. Plastic thermocol is also deposited on the banks of rivers. Leftovers, leaves, everything is thrown into the river water after the ceremony in the village or town along the riverbank or on the riverside. Sometimes garbage from municipal and panchayat areas is also dumped on the banks of the river. On the other hand, encroachment is also increasing in and around Shilabati. Big pillars are rising near the land on both banks of the river in Ghatal town. Shops and houses are being built. The normal flow of the river is obstructed by the construction of numerous shops in bamboo structures on the banks of the river. According to the Irrigation Department, about seventy percent of the land on both sides of the river Shilabati is in the possession of others (Fig. 2.2). Someone is living there permanently. Someone is doing business again. Sand is mined from Shilabati River at Khirpai, part of Chandrakona. The riverbed is being cut in such a way by bringing down machines to collect sand, which is affecting the ecosystem of the river.

2.5 River Water Characteristics Suspended solids, waste, sewage, and plankton result in turbidity in water [4, 5, 8]. The quality of suspended solids in the river water generally depends on the sediments contributed locally and release of sewage loads from nearby municipal areas [11]. Total suspended solids range from 8 to 396 mg/l and fluctuates mainly during premonsoon and monsoon seasons depending on the local contribution of the waste

2.5 River Water Characteristics

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Fig. 2.2 Shilabati River with huge turbid water at its downstream of Ghatal, Paschim Medinipur

materials from nonpoint sources as well as from the Ghatal municipal areas. Water lathering in the river water adjacent to the municipal areas caused by the solution of soap and detergents is prevented by the hardness which is considered as an important property of water [6, 7]. Consumption of water with hardness beyond the permissible limit results in severe stomach upset with numerous other symptoms in human beings [12]. Total hardness varies from 40 to 140 ppm in Shilabati River water adjacent to Ghatal municipality of Paschim Medinipur district. The pH of river water ranges from 6.4 to 8.35, representing both acidity and alkalinity characteristics [1, 2]. pH is mostly acidic during pre-monsoon time and alkaline in the post-monsoon season in the river water of Shilabati at Ghatal downstream areas [10, 15]. The presence of

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Table 2.1 Water quality index of river water of Shilabati River at Ghatal downstream Shilabati River Ghatal downstream Year/Season

Pre-monsoon

Monsoon

Post-monsoon

Min

Max

Min

Max

Min

Max

2013–14

42.2 (Good)

39.41 (Good)

8.74 (Good)

38.87 (Good)

28.4 (Good)

37.33 (Good)

2014–15

40.42 (Good)

64.16 (Poor)

22.22 (Good)

46.37 (Good)

34.73 (Good)

41.64 (Good)

a few small-scale industries like insane stick and battery manufacturing units on the bank of Shilabati may cause the river water to become acidic in nature for the period from February to May in a year. The count of faecal coliform bacteria in the river water is very high and varies from 2000 to 80,000 MPN/100 ml [1, 2] though the name of river Shilabati is excluded from the list of the polluted river of West Bengal as BOD level of surface water samples of the river show lower values than that of the permissible limit as prescribed by the Central Pollution Control Board [3].

2.5.1 Water Quality Index River water of Shilabati receives wastes from both point and nonpoint sources around its flow path. Sometimes sediments meet the river water that not only increases the chemical water parameters like turbidity and total dissolved solids, but the sediments accumulated in the riverbed that decrease the water catchment areas of the river. The water quality index is measured using the standard statistical formula and applying the values published in the Database on environment of Pollution Control Board in 2015 [1, 2]. The result reveals that the water quality condition is good in major seasonal period, but the water is not usable as the coliform bacterial counting of the river water exceeds to much more than that of the number prescribed by the Central Pollution Control Board for drinking and outdoor bathing in the river water or washing utensils or cloths in it (Table 2.1).

2.6 Summary Most of the properties responsible for the poor water quality of the Shilabati River have no specific source. Due to the natural beauty of the Gangani caused by erosion on the banks of the Shilabati River, the influx of tourists and the waste they leave behind, a few factories manufacturing incense sticks and batteries, pipes of public toilets directly come into the river and pollute the river water. Sewage from Ghatal

References

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Municipality is mixed with the river water without treatment via the pipeline which is the only point source of water pollution in Shilabati River. Despite the situation, the water quality of the Shilabati river is good, although the water is unfit for domestic purposes, and this is because of the presence of faecal coliform bacteria in the river water which is several thousand times higher than the acceptable limit [14]. The municipal management should take the initiative to stop littering on the banks of the river. Common people should also be aware of polluting agents. Efforts should be made to keep the river clean. Excessive use of river resources must be stopped. The state administration has to stop the normal speed and rush to occupy the riverbed that leads to the return of Shilabati’s natural scenario to its former state. Let the municipality also be proactive. At least all the residents living around the river come forward to stop littering on the banks of the river. Otherwise, the life of the river is ruined. And the effect of that waste will come on people.

References 1. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 2. Anonymous (2020) Action plan for rejuvenation of river Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate Department of Urban Development & Municipal Affairs Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 3. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi, 110032, p 94 4. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, 15–16 5. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari river, West Bengal. Indian Sci Cruiser 18(4):16–21 6. Das GK, Datta S (2006) Managing Waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 7. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 8. Das GK, Datta S, Sanyal SK (2004) Need for geomorphic mapping in terms of physico-chemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 9. Das GK (2003) Changing environment and responses of the living Systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 10. Das GK (2006) Sunderbans—Environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN: 81-87169-72-9 11. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN: 978-3-319-11342-5 12. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN: 978-3-319-44190-0 13. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN: 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1

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14. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 15. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN: 978-3-031-18845-9. https://link.springer.com/book/10.1007/9783-031-18846-6

Chapter 3

Environmental Deterioration of Churni River

Abstract Churni, a distributary of Mathabhanga River and about 56 km in length, is presently in dying state due to periodical release of industrial water effluents in the Mathabhanga River from a sugar manufacturing plant and distillery unit of Bangladesh. Dissolved Oxygen in the river water becomes nil when the sugar producing plant releases untreated industrial sewage sludge and water effluents. The Water Quality Index revealed the poor quality of river water for use by the riverside inhabitants. The black dolphins have gradually been decreasing in the river water of Churni, their natural habitat, due to such aquatic pollution. Keywords Water quality determinants · Churni River · Anjana River · Mathabhanga River · Biochemical Oxygen demand · Chemical Oxygen demand · Microorganisms · Water quality index

3.1 River Environments The water quality of Churni River has gradually been deteriorating due to mixing of wastewater released by a sugar manufacturing plant without proper treatment. Carew and Company, the sugar and distillery manufacturing unit of Darshana, Bangladesh discharges industrial wastewater 4–6 times annually within Mathabhanga River that contains huge quantities of organic matter. All such organic matter comes from Mathabhanga River and mixes in the water of Churni River. Due to decomposition of all those organic matters just 2–4 days after their release, the dissolved oxygen of the river water becomes below detectable level i.e., dearth of dissolved oxygen that changes colour of the river water of Churni River turning into black [8, 11]. Along with the degradation of dissolved gases groups like dissolved oxygen etc., nutrient group like Kjeldahl-N, Ammonia-N, organic group like biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, total fixed solids, metal group like arsenic, boron, sodium have been depleted for the discharged wastewater from the sugar and distillery plant situated in Bangladesh. On the contrary, microbial groups like fecal coliform, total coliform, have been

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increasing with large numbers after getting their favourable environment for growth and proliferation due to availability of huge quantities of nutrients [16, 17]. Considering all these organic, metal, chemical, and microbial parameters, the computation of water quality index would be helpful for the interpretation and to determine the magnitude of environmental degradation of Churni River of Nadia district in West Bengal.

3.2 Churni River Systems The canal dug by Maharaja Krishna Chandra from Majdia to Krishnaganj is probably the Churni River which later acquired the status of a river. The Churni River starts flowing as a distributary of the Mathabhanga river from Majdia in Nadia district and the flow path of this river is about 56 km. There are about 120 villages along the course of Churni River. The latitude and longitude at the place of origin of Churni River are 23°40, 17.7,, N & 88°70, 36.5,, E. It is a local belief that a part of Churni River is said to have been created by canalization from Shiv Nibas of Majdia to Krishnaganj of Nadia district. Maharaja Krishna Chandra ordered a canal to be cut in the seventeenth century to avoid Bargi attacks. Later that canal took the form of a river. However, in 1916, the report of a river expert of the Calcutta Port, considered this river to be natural [18]. This river takes a curved path from Majdia passing through some notable places like Hanskhali, Kalinarayanpur, Aranghata, Ranaghat and meets the Hooghly River at Shibpur near Gonsaier Char (Fig. 3.1). The latitude and longitude at the confluence of Churni and Hooghly rivers are 23°13, 57.8,, N & 88°50, 08.4,, E. The river course of Churni has been repeatedly blocked by human activities. At present, the construction of an alternative bridge is going on at Ranaghat for the expansion of the national highway and that stopped the natural flow of Churni River. The national highways development authority has not taken any environmentally friendly steps to save the river. However, the road widening department has said that after the completion of the bridge construction, it will be returned to its old form. In this situation, environmental activists and the fishing community are counting the days to see when the Churni will return to its previous flow path. But this is not the first time that road expansion has been done by blocking the course of the river. Earlier, the river flow was blocked several times during the construction of Dwijendralal Roy Bridge near Kalinarayanpur by the Railway Department and Anulia-Majdia Concrete Bridge by the government roadway sector. Every time the concerned authority or the contractor assured of dredging the river. But afterwards no one felt the need to keep the promise. The flow of the river is obstructed by the use of boulders, excavated soil and various plastic drums. As a result, pollution is increasing. The riverbed is filled with water hyacinth and garbage because the flow path is closed. The fishing community living in the river basin is the most affected by this environmental degradation.

3.2 Churni River Systems

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Fig. 3.1 Churni River at Aranghata in Nadia district

Churni River became swollen in the seventeenth century by receiving the headwater discharge of Mathabhanga River and water from the Jalangi River from the east. Currently Churni is almost waterless except during the monsoon season. The riverbed is elevated due to the accumulation of sediment. People have occupied and started farming across the river floodplain. Due to this reason, when the headwater from Padma River flows through Mathabhanga River and falls into the Churni River during heavy rain in the monsoon, the Churni River overflows its banks and floods. The confluence of Churni and Hooghly is best seen at Gonsaier Char. The black water of the polluted Churni and the muddy water of the Hooghly are observed flowing separately at the confluence [18].

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3.3 Anjana River Churni River connects Anjana River which is a distributary of Jalangi. The Anjana River meets the Churni River where it ends its journey. Anjana River, a connector between Jalangi and Churni rivers, served as drains to intercept the enemy and to meet domestic water needs for centuries. But later the Jalangi River changes its course due to geographical reasons, then silt accumulates in the riverbed of Anjana and gradually becomes an abandoned river covered with water hyacinth (Fig. 3.2). The place of origin of Anjana River was first blocked by an ancestor of Maharaj Krishna Chandra to stop consecutive Muslim attacks by boats utilizing navigability of Anjana River. Then during the British period, a sluice gate was constructed to control and manage its headwater discharge from the river Jalangi that enabled adequate water supply in and around Krishnanagar areas. Maharaja Krishna Chandra ordered a canal to be cut around to protect the subjects from the Bargi attacks, that is probably, and is currently known as Churni River. Churni River is connected with Jalangi River by Anjana River which will also work as a test to escape from the attacks of the Bargi by digging a lake around the royal palace of Maharaja Krishna Chandra. Anjana River will also be useful for the daily use of the common people including drinking water from both sides of its water course. But later due to the change of the river course of Jalangi as well as blockage at the head, Anjana River got separated from Jalangi, due to which the water level and flow in Churni River also decreased. Anjana really cannot be called a river anymore as water from the field passes, fish is cultivated by excavating ponds, and jute is processed by rotting in the riverbed and the rest is covered with water hyacinth. Although Anjana is a small river of only about 27 km, it swelled during the seventeenth century after receiving the water of Jalangi. But now there are many ponds in the riverbeds, floodplains, or along the banks in the silted dying river and those ponds or lakes are named after their old owners. The names of such ponds and lakes from the north to south are successively—Raj Dighi, Ghosh Pukur, Nabani Babur Pukur, 17 Hat Kalitala Pukur, Patuli Pukur, Dutta Pukur, Das Pukur, Anjangarh Pukur, Bazar Pukur and many other ponds whose names are not available. Anjangarh pukur and Bazar pukur stand in Badkulla. Patuli pukur, and 17 hat Kalitala pukur are in neighboring Patuli. All such ponds or lakes are either occupied or excavated in the riverbeds of the Anjana.

3.4 Mathabhanga River Mathabhanga River is a distributary of Padma River and flows from Munshiganj of Bangladesh to Majdia of Nadia where it bifurcates to Churni and Ichamati rivers (Fig. 3.3). The Mathabhanga River flows southward from the Padma River near Munshiganj in the Kushtia district of Bangladesh and after entering Indian part, the river Mathabhanga provides its headwater supply to only Churni River though

3.4 Mathabhanga River

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Fig. 3.2 Anjana River covered with water hyacinth at Badkulla of Nadia district

it bifurcates near Majdia to form two tributaries named Churni and Ichamati. The riverbed of Ichamati is comparatively higher than that of the Churni River. So, the water of Mathabhanga River flows through the riverbed of Churni. Other than that geographical reason, during the construction of the railway bridge, the mouth of the Ichamati River was raised by boulders, bricks, sand, and mud at the head of the river about two centuries ago. This is one of the reasons why the Mathabhanga River does not flow through the comparatively elevated Ichamati River except during the monsoon time. A portion of the riverbank is covered with bushes and jungles comprising mixed vegetation near Gede border areas [1, 15].

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Fig. 3.3 Mathabhanga River at Majdia in Nadia district

3.6 Water Quality Determinants

45

3.5 Fish and Fishing Community About 30,000 fishermen living in 120 villages along the course of Churni River earn their living by catching the fish. Many kinds of fish are found in Churni River water like lal punti, tit punti, tip punti, sar punti, chand punti, lal saral punti, chela, kakchi, batasi, magur, boyal, kan koi, rongin kholse etc. Apart from these native species of fish, Churni is famous for one more reason, and that is the black dolphin found in this river. Like native fish, black dolphins in this river are also declining in numbers. The Churni River gets the status of International River due to the presence of black dolphins in the river water. Due to the effect of polluted wastes discharged by Carew and Company without treatment, there is lack of dissolved oxygen in the water of Mathabhanga and Churni rivers respectively. This condition persists for 8–10 days after discharge of contaminated wastewater. In such a situation, the fish all started floating in the Churni River and died after a while.

3.6 Water Quality Determinants Generally, three types of adverse effects are observed when the river water receives the wastewater from the canals or drainage systems that flow directly from the municipality or urban areas [19]. Changes in turbidity, temperature, water colour including several other surficial properties may be considered as physical pollution [2, 3, 12]. Oxygen depletion or eutrophication results can cause either organic or inorganic nutrient pollution [13, 14, 26]. Changes of toxicity, acidity, alkalinity, or salinity alternations are directly related to chemical pollution which are revealed by the determination of pH, conductivity, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), Total Fixed Solids (TFS), Total Alkalinity (TA), Total Hardness (TH), Total Kjeldahl Nitrogen (TKN) and the most probable number (MPN) of microbial organisms like fecal coliform bacteria in the river waters contaminated with the liquid effluents from the industrial plants along with domestic sewage released from the municipality and urban areas results the microbiological water pollution [27, 28]. Industrial water effluents mixed in the Mathabhanga River water at Darshana of Bangladesh contaminate river waters of Churni.

3.6.1 Biochemical Oxygen Demand Quantity of dissolved oxygen (mg/l) required for the stabilization of organic matter to be decomposed by biochemical action in aerobic situations is biochemical oxygen

46

3 Environmental Deterioration of Churni River

demand (BOD). For the analysis of BOD, two factors like temperature and time are very important to obtain accurate and reproducible results. BOD determination takes a long time to yield a satisfied result for e.g., minimum 100 days are required to obtain a more precise value of BOD of the domestic sewage released and mixed in the river waters. Naturally, determining the BOD of river water in time is really a hard task for obtaining significant value, if there is any. A 5-day incubation of the river water sample has been considered as the elapsed time and the attainment of reaction at its normal rate is observed in the 5 days lag period [22]. Thus, the time factor is shortened to a 5 days interval for the determination of BOD. Further, temperature governs all activities along with the chemical and biochemical reactions. A rise in temperature of about 10 °C and around 20 °C causing almost double of the speed of chemical reaction as well as biochemical reactions leads to the consideration of 20 °C limit as the acceptable temperature for the determination of BOD. Therefore, in practice, BOD has been analyzed after incubation of river water samples for a period of 5 days with an arbitrary temperature of 20 °C, though the incubation for 3 days at 27 °C repeats the same values of BOD for the 5 days incubation in 20 °C. Now 3 days incubation for BOD analysis is in practice. The permissible limit of BOD concentration is 3 mg/l for outdoor bathing in river water in terms of standard values fixed by the Central Pollution Control Board, Ministry of Environment and Forest, Government of India [2]. The process of decomposition of the domestic sewage has been performed through two consecutive stages where the initial stage is carbonaceous decomposition followed by nitrogenous decomposition. The nitrogenous decomposition stage is a lengthy process as the decomposition of nitrogenous materials of the domestic sewage released in the river waters starts decomposition after the seventh to tenth day. And among the two-fold stages of nitrogenous decomposition, the nitrogenous reaction of the nitrogen cycle moves off and on in the reverse direction instead of further proceedings because of the existence of some complex nitrogen compounds or nitrogen fixing bacteria. For these reasons, BOD of sewage fed river waters is generally determined with the stage of carbonaceous decomposition [6]. The BOD value ranges from 1.6 to 38.02 mg/l for the water samples of Churni River [2, 3].

3.6.2 pH and Biochemical Oxygen Demand Microbial organisms, habituated to a narrow range of pH, accelerate the biochemical reaction as well as decomposition process of domestic sewage and generally, the pH ranges between 6.5 and 8.3 [7, 8]. The pH ranges from 7 to 8.3, obtained from the chemical analysis of the river water samples in three different seasons like premonsoon, monsoon, and post-monsoon perfectly accomplished the decomposition of organic matter in the waters of the Churni River. As the obtained pH range is not lower than 6.5 or slightly higher than 8.3 for the biochemical oxidation of organic matter, adjustment to pH 7.2 is not necessary for the reliable result of BOD values

3.6 Water Quality Determinants

47

of the water samples of the Churni River. The pH of river water samples collected from Churni ranges from 7.12 to 8.36 [2].

3.6.3 Nutrients and Biochemical Oxygen Demand Generally, BOD shows significant values for the industrial wastewater samples as such water contains adequate nitrogen and phosphorus [10]. Water samples collected from the Churni River reveal lower BOD values due to lack of adequate nutrients comprising nitrogen and phosphorus. Total Kjeldahl Nitrogen (TKN) of the water samples varies from 0.24 to 5.56 mg/l. Sometimes the technique of dilution water design for measuring BOD taking the samples as natural water to provide nutrients like nitrogen and phosphorus helps obtaining reliable values of BOD.

3.6.4 Microbial Organisms Microbial organisms comprising bacteria, algae, fungi, and protozoans have abundantly occurred in the river water of Churni. Facultative bacteria, the predominating microbial organisms, consists of both aerobic and anaerobic bacteria that accelerate breakdown of organic matter. Along with the microbial organisms, snails, worms, insects, frogs, snakes, fishes etc. represent the animals of higher trophic levels. Among microorganisms, fungi assist waste stabilization under low pH conditions. Sometimes, the prolific growth of fungi causes clogging of gills of aquatic animals that results in menace of fishes and other higher animals. Huge fungal growth even restricts the ventilation of higher animals. Apart from fungi, growth of algae depends on the availability of sunlight. Among several algal populations, Chlorella, Phormidium, and Ulothrix are very common species. Algal population enhances oxygen concentration in the river water, but excessive growth clogs the riverbed that causes bad odour in and around the riverine environments. Vorticella, Epistylis, and Opercularia and other species, representatives of protozoans, control the bacterial proliferation utilizing food rapidly and thereby, control the nutrient conditions of the river water. The occurrences of such microbial populations are influenced by the availability of dissolved oxygen, temperature, pH, and ultimately the composition of wastes and sewage released in the river water [4, 9]. The river water of Churni receives microbial organisms from the domestic sewage and municipal wastes released in the rivers through drainage systems. Microbial organisms are grown abundantly in huge numbers taking organic materials of the sewage as food stuff. The microbial organisms, different in species and varieties in biological forms, are propagated not only in various methods, but also contaminate different contagious diseases to the inhabitants living in and around Churni River who use river waters for drinking and domestic purposes. Using such contaminated water of the Churni River for drinking purposes caused several cholera epidemics

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due to contagious fecal coliform bacteria in the nineteenth century as there were no other sources of drinking water supply to the locals during that era. Industrialization creates a new environment for microbial organisms as the industrial wastes, rich in nitrogen and phosphorus, provide comparatively rich nutritional conditions which are utilized by the organisms. This condition is applicable to the river waters of Churni as the river receives industrial effluents from sugar manufacturing plants as well as wastes in the form of domestic sewage and sewage sludge from Ranaghat municipality. So, there is a huge probability of acclimatization of the most dominant microbial organisms like fecal coliform for a new environment and nutrient conditions in the river waters though fecal coliform develop in huge numbers and that numerous coliforms pollute the river water round the year. Thus, the river water of Churni got polluted. The water quality index revealed that the river water is below the permissible limit for domestic purposes. Fecal coliforms grow sporadically as the river water of Churni is almost stagnant except during the monsoon. The most probable number of fecal coliform per 100 ml river water samples ranges between 2000 to 50,00,000 whereas in Mathabhanga River, fecal coliform occurs in large numbers, and it varies from 4000 to 90,00,000 MPN/100 ml [2]. The number of faecal coliform bacteria is higher in Mathabhanga River than that of Churni River as the former receives wastewater directly from the sugar and distillery manufacturing unit at Darshana in Bangladesh.

3.6.5 Chemical Oxygen Demand River water samples containing more than 15 mg/l organic carbon content have generally been undertaken for the analysis of chemical oxygen demand (COD). COD analysis is concerned with rigorous chemical oxidation and for this reason, COD values show no relationship with that of BOD [24]. BOD is a test that utilizes a biological process in comparison to the chemical oxidation for COD analysis. Determination of COD shows the values of requirement of quantity of oxygen for the oxidation of organic matter of water samples where domestic sewage is released frequently or occasionally [23]. As there is no similarity with the methodology of other tests like BOD or DO, COD is considered as an independent test and the values obtained in the COD test have no influence on the other chemical parameters of the wastewater samples in particular areas along the course of Churni River. Chemical Oxygen Demand (COD) ranges from 10 to 129.31 mg/l for the river water of Mathabhanga, and between 7.83 and 51.57 mg/l for Churni River [2].

3.7 River Water Characteristics

49

3.7 River Water Characteristics Central Pollution Control Board standardized the liquid effluent of sugar industry for the disposal in surface water in terms of EPA Notification vide S.O. 844 (E) dated 19.11.1986 and the standards shows the values of BOD and TSS are 30 mg/l for disposal in surface waters [1]. The BOD level of the liquid effluent is much higher than the permissible limit which is released in the waters of Churni River. Release of such highly polluted effluent into the river waters of Churni results in higher BOD and COD values and obtained DO shows low values and sometimes even it is nil. The river water turns blackish most of the days of the year and becomes green during the rainy season due to a higher rate of eutrophication. The liquid effluent of the sugar industry contains huge amounts of nutrients that results in greenish water colour due to the rapid increase of the algal population or algal bloom. Mathabhanga River carries those liquid effluents from the Carew & Co. (Bangladesh) Ltd., of Darshana, one of the 15 nationalized sugar making companies of Bangladesh and such liquid effluents of the sugar mill mix with the water of Churni and Ichamati River near Majdia of Nadia district where Mathabhanga is bifurcated to Churni and Ichamati rivers. Another sweet producing manufacturing plant, Khamar Simulia Batasa Sugar Factory (Batasa—dried sweet sugar drop), stands nearby Churni River and is responsible for the release of liquid effluent passing through the drainage system. The sugar and distillery producing industrial plant Carew & Co (Bangladesh) Ltd of Darsana in Bangladesh discharges industrial liquid effluents throughout the different stages of sugar and liquor processing. The distillery unit of the company produces indigenous wine and foreign liquor from the molasses and sugar canes. Wastewater effluents of the distillery units are characterized with low pH, high organic matter, high COD, high suspended and dissolved matter containing high potassium, and nitrogen. Different types of industrial plants release wastewater of different natures and quantities. Distillery plants release a huge quantity of effluent water due to the mechanism of processes and for the purpose of cooling the liquor produced. Such large quantities of liquid effluents from the distillery plants contain suspension solid matters and substances that cause pollution. So, distillery industrial plants like Carew & Co (Bangladesh) Ltd., of Darsana in Bangladesh at the extreme upstream of the Churni River is an individual problem causing pollution of river water, the water quality of which is beyond permissible limit for using it for domestic purposes. Liquid effluents with low pH released from the distillery plant become high in the downstream of Churni River after crossing a long distance from the headwater of Mathabhanga to the Churni downstream at Ranaghat town via Majdia. pH of the river water of Churni downstream at Ranaghat town varies from 7.12 to 8.36 in 2013–14 and 2014–15 respectively [2]. Churni River is still enlisted as a polluted river of West Bengal in the category of Priority III as mentioned by the Central pollution Control Board in their recent report [5].

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The river waters of Churni get polluted only when the sugar producing plant drains water effluent into the Mathabhanga River. Physicochemical parameters of river waters for both rivers reveals that the concentrations of chemical parameters of Mathabhanga River at Gobindapur and upper stretch of Churni River at Majdia are almost higher than those of the river water samples downstream at Ranaghat town. The river water of Churni required different levels of treatment for using it for outdoor bathing, drinking, or for irrigation purposes in the agricultural sector. For such treatment, chemical parameters of the river water like pH, conductivity, DO, BOD, COD, TDS, TSS, TFS, TA, TH, TKN etc. are to be standardized to the permissible limit for domestic or agricultural usage [21]. Chemical parameters like total dissolved solids (TDS), total suspended solid (TSS) and total fixed solids (TFS) are carried by the river like Churni in normal situation along its course, but their values become hazardous only when the wastewater from the sugar and distillery plant are mixed with the river water carried by the Mathabhanga River from its upstream. TDS varies from 168 to 504 mg/l for Mathabhanga River and 40 to 482 mg/l for Churni River. TSS ranges from 12 to 274 mg/l for Mathabhanga and 6 to 358 mg/l for Churni River. TFS varies from 184 to 484 mg/l in the river water of Mathabhanga and 168 to 476 mg/l in the waters of Churni River [2]. TDS, TSS, and TFS values are rather higher for the river water of Mathabhanga in the upstream than that of Churni River in the downstream only except a few exceptional cases [25]. The river water of Mathabhanga and Churni is alkaline in nature where pH of the river waters ranges from 7.03 to 8.49 for Mathabhanga and 7.12 to 8.36 for Churni River. Total Alkalinity (TA) ranges from 88 to 496 mg/l in the water samples of Mathabhanga and 92 to 604 mg/l for Churni River [2]. Inclusion of huge quantities of bicarbonate into the river waters from the drainage system of the municipal areas in the form of detergent and soap causes the increase of total hardness (TH) of Churni River. The presence of bicarbonate in the water enhances such temporary hardness which is removed through the process of conversion of bicarbonate to carbonate. Generally, carbonate form is available in the river water of Churni that controls such conversion of bicarbonate to carbonate. Total hardness (TH) varies from 111 to 333 mg/l in Mathabhanga and from 100 to 412 mg/l in the river waters of Churni [2]. Total hardness is comparatively higher because of the presence of municipal areas at the riverside of Churni that drain detergent mixed municipal wastes into the river, though hardness is not a pollution parameter but a water quality indicator.

3.7.1 Water Quality Index (WQI) Uses and utilization of river waters are generally determined by some selected physicochemical parameters like pH, conductivity, DO, BOD, COD, TDS, TSS, TFS, TA, TH, calcium, magnesium, faecal coliform etc., and water quality index are computed averaging weight of some of the selected water parameters like pH, conductivity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, total fixed solids, total alkalinity, and total

3.7 River Water Characteristics

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hardness according to their significance and importance in a particular environment [19, 20]. In the present study, water quality index (WQI) is calculated applying the standard statistical formula considering the minimum and maximum values of individual physicochemical parameters of Churni, Jalangi, and Mathabhanga rivers based on Database on environment and forestry statistics of West Bengal [1]. After computation of water quality index, water quality rating is obtained applying the values of WQI on the chart for water quality rating. WQI is computed from the obtained data from the laboratory analysis applying statistical methods using the standard values fixed by the Central Pollution Control Board (Tables 3.1 and 3.2). Computation of physicochemical parameters reveal that the water of Churni River is of poor quality (> 60) round the year only except for a part of the monsoon time in the downstream portions of the river (Table 3.1). The presence of large numbers of faecal coliform bacteria leaves the river water beyond usage for drinking, outdoor bathing or for any other domestic use like washing of utensils. About 25% good, 25% fair, and 50% poor water conditions are observed for Churni River in 2013– 14, and 2014–15 respectively as per water quality rating obtained from the water quality index values after computation applying standard statistical formula. The WQI values revealed that the water quality of Churni River is rather better than that of Mathabhanga River in terms of water quality index (WQI). Table 3.1 Computed water quality index of river waters at different locations of Churni Year

Sample Locations

Pre-monsoon

Monsoon

Post-monsoon

Min

Max

Min

Max

Min

Max

2013–14

Majdia

53.414 (Fair)

73.341 (Poor)

31.006 (Good)

58.462 (Fair)

43.89 (Good)

72.743 (Poor)

2014–15

Majdia

60.061 (Fair)

73.377 (Poor)

30.929 (Good)

54.504 (Fair)

60.458 (Fair)

73.478 (Poor)

2013–14

Ranaghat

65.291 (Poor)

74.245 (Poor)

37.136 (Good)

64.186 (Poor)

34.759 (Good)

76.197 (Poor)

2014–15

Ranaghat

57.411 (Fair)

80.621 (Poor)

31.113 (Good)

69.145 (Poor)

61.92 (Poor)

75.328 (Poor)

Rating of water quality within parenthesis

Table 3.2 Computed water quality index of river waters at downstream stretch of Mathabhanga Year

Sample Locations

Pre-monsoon

Monsoon

Min

Max

Min

Max

Min

Max

2013–14

Gobindapur

66.04 (Poor)

83.85 (Poor)

37.16 (Good)

62.59 (Poor)

34.0 (Good)

71.26 (Poor)

2014–15

Gobindapur

63.03 (Poor)

74.33 (Poor)

32.16 (Good)

74.42 (Poor)

60.6 (Fair)

74.27 (Poor)

Rating of water quality within parenthesis

Post-monsoon

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The Ranaghat Municipal Corporation has planned to treat the Churni River to free from water pollution. For this work, several wastewater treatment plants have to be constructed for which the cost is estimated at Rs 45 crores. The state government has already allocated Rs 4 crore in the first phase for the construction of a sewerage plant downstream of Churni River. In the upstream, the Indian High Commission in Dhaka has been asked by the Central Ministry of Foreign affairs to present the issue of wastewater emissions in Churni River through Mathabhanga River from Bangladesh’s sugar mills to the Bangladesh Government as soon as possible. Industrial water effluents mixed in the Mathabhanga River water at Darshana of Bangladesh ultimately contaminate river waters of Churni River. From the computed water quality index, water quality rating indicates that Mathabhanga river water contains about 25% good, 66% poor, and only 9% fair water as per standard water quality rating chart during three principal seasons of South Bengal i.e., pre-monsoon, monsoon, and post-monsoon in a year (Table 3.2). Due to the existence of 66% poor surface water of the river, Mathabhanga river water is not suitable even for outdoor bathing.

3.8 Summary Local inhabitants living in the vicinity to the Churni River never use its polluted black water for outdoor bathing or drinking by knowing not about the water quality index or the chemical parameters of the water samples, but the people simply identify polluted river water by its blackish colour or odour of the stagnant river water. The inhabitants living around the Churni River unanimously want the river water to be clear and clean like the previous time. In these circumstances, the concerned authority of the government sector should direct the sugar factory owners not to release liquid effluents in the river waters, but it may be released in their own land areas scheduled for the disposal of effluents purchased by the factory owners or release of those water effluents after wastewater treatment in due course. The permissible limit of chemical parameters like BOD and TSS for liquid effluents are comparatively higher in the surface waters of Mathabhanga River and upstream of Churni River near Majdia. Simultaneously with the steps to be taken by the government sector like state pollution control board for making river water to be pollution free, and the irrigation and inland waterways board must dredge the river along its upstream to the confluence which will increase the volume of the riverbed and change the river flow velocity at its normal rate. The higher water mass in the riverbed not only results in the purity of river water, but also it will support the common concept like dilution is the solution to pollution.

References

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References 1. Anonymous (1996) Standards for liquid effluents, gaseous emissions, automobile exhaust, noise and ambient air quality. Central Pollution Control Board (CPCB), Ministry of Environment and Forests, Government of India, Pollution Control Law Series, PCL/4/1995-96 2. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 3. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 4. Bartha C, Jipa M, Caramitu AR, Voina A, Tókos A, Circiumaru G, Micu DD, Lingvay I (2022) Behavior of microorganisms from wastewater treatments in extremely low-frequency electric field. Biointerface Res Appl Chem 12(4):5071–5080. https://doi.org/10.33263/BRIAC124.507 15080 5. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi, 110032, p 94 6. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 7. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 8. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 9. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 10. Das GK, Datta S, Sanyal SK (2004) Need for geomorphic mapping in terms of physico-chemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 11. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 12. Das GK (2006) Sunderbans—Environment and ecosystem, Sarat Book House, Kolkata, p 254. ISBN: 81-87169-72-9 13. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN 978-3-319-11342-5 14. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN 978-3-319-44190-0 15. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1 16. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 17. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 18. Das GK (2023) Water quality index of Churni and Jalangi rivers, West Bengal, India. Int Res J Environ Sci 12(1):14–18 19. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 20. Galal Uddin Md, Nash S, Agnieszka I, Olbert A (2021) Review of water quality index models and their use for assessing surface water quality. Ecol Indicators 122:107218. https://doi.org/ 10.1016/j.ecolind.2020.107218

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21. Langone M, Sabiab G, Pettab L, Zanettic L, Leonic P, Bassoc D (2021) Evaluation of the aerobic biodegradability of process water produced by hydrothermal carbonization and inhibition effects on the heterotrophic biomass of an activated sludge system. J Environ Manage 299. https://doi.org/10.1016/j.jenvman.2021.113561 22. Muralikrishna IV, Manickam V (2017) Analytical methods for monitoring environmental pollution. Environ Manage. https://doi.org/10.1016/B978-0-12-811989-1.00018-X,495-570 23. Subramanian V (2011) A textbook of environmental chemistry. I.K. International Publishing House Ltd., New Delhi, pp 1–482. ISBN 978-93-81141-19-9 24. Tyagi VK, Lo SL (2016) Energy and resource recovery from sludge: full-scale experiences, environmental materials and waste, resource recovery and pollution prevention, pp 221–244. https://doi.org/10.1016/B978-0-12-803837-6.00010-X 25. Weide T, Brügging E, Wetter C (2019) Anaerobic and aerobic degradation of wastewater from hydrothermal carbonization (HTC) in a continuous, three-stage and semi-industrial system. J Environ Chem Eng 7(1). https://doi.org/10.1016/j.jece.2019.102912 26. WHO (2004) Health risks from drinking demineralized water. WHO, USA 27. WHO/UNICEF (2005) Water for life: making it happen. ISBN 92-4-156293-5 28. WRN (2016) Water Research Net, pH in the environment. Available from http://www.waterresearch.net/index.php/ph-in-theenvironment. Accessed 3 June 2016

Chapter 4

Mayurakshi River—Water Resources and Environments

Abstract Mayurakshi flows through Birbhum district, and this river can be called the lifeline of this district. Birbhum district is known as one of the driest districts of West Bengal due to low annual rainfall. In such a situation, the Mayurakshi River provides much of the water for supplying irrigation water to people’s day-to-day use, to a dry district like Birbhum. For the purpose of water supply, the state government has constructed reservoirs and irrigation canals with dams and barrages on the Mayurakshi and its tributaries. But since the volume of water carried by these rivers and their tributaries is not very high, no reservoirs have been constructed to control the floods. As a result, if the concerned department of the government is forced to release a lot of water at once from the reservoir of the dams and barrages due to excess rainfall during monsoon in a year, flooding occurs across the Mayurakshi River basin. Water quality of the Mayurakshi River is good and it was recently excluded from the list of polluted rivers in India by the Central Pollution Control Board. Keywords Mayurakshi · Dwaraka · River commons · River project · Water quality · Catchment areas · Flood situations · Kuiya

4.1 Mayurakshi River Course Mayurakshi River originates from Trikut Hills in Jharkhand. After this, the river passes through the Deoghar and Dumka districts of Jharkhand through the eastern branch and enters Birbhum district via the Jharkhand-West Bengal border. Finally, the river flows through Murshidabad district and joins the Hooghly River. It has many tributaries along its course. The total flow path of the river is 250 km. Some of the important towns along the flow path of Mayurakshi River are Deoghar, Dumka, Suri, and Sainthia. This river has many small and large tributaries which are the main source of water of this river. The left tributary of the river is Brahmani River whereas the right tributaries are Bakreshwar, Kopai, Dwaraka, and Kushkarni. The river belongs to the Damodar Valley Corporation (DVC) scheme. Two dams are noticeable on the Mayurakshi river course. The first one is Massanjore Dam which is located along

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4 Mayurakshi River—Water Resources and Environments

Fig. 4.1 Construction of revetments by using boulders for remedial measures of bank erosion and temporary road across Mayurakshi River for easing transport and communication facilities almost blocked the river course near Sainthia town in Birbhum district

Dumka Suri Road in Dumka district of Jharkhand also known as Kanara Dam, another is Suri Tilpara Dam which is located near Suri town in Birbhum, West Bengal. Both these dams are mainly used for irrigation purposes. However, about 4 megawatts of hydroelectricity is also generated from Massanjore Dam. Although the river did not flood before damming, it has experienced severe floods several times since damming. Again, after being dammed, the Mayurakshi River has provided irrigation water to dry districts like Birbhum and made crops grow. Sometimes, due to the construction of boulder walls on the banks of the river to avoid flooding, the river’s course is becoming narrower, and the lifespan of the river is decreasing (Fig. 4.1).

4.2 Riverine Environments Bakreshwar and Kopai rivers flow in the southern part of Birbhum. These two rivers merge and enter Murshidabad district under the name Kuye and join the Mayurakshi River. The people of this country have to fight more with the soil than with the river. In extreme heat, rivers dry up and look like deserts. There is only sand, silt and stones all over the riverbed. During lean time, on one side, a knee-deep river flows. Even

4.3 Mayurakshi–Babla River Systems

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the grass dries up in the land around the river in summertime due to scorching heat. The surface soil becomes hot like iron burning in fire. The soil then becomes hard and cannot be plowed even with a spade. Mayurakshi or Mor River is fed by the combined flow of Matihari, Dhobbi, and Pusharo from the upper hilly areas of Santhal Pargana of Bihar State. Before entering Birbhum district of West Bengal, Mayurakshi River is fed by the combined streams of Siddheswari and Nunbil. After entering West Bengal two small streams named Kushkarni on the right and Ghoshbera on the left join the river. It then crosses the Birbhum district boundary and joins the Dwarka River at Talgram in Murshidabad district and the combined flow falls into the Bhagirathi River which ultimately outfalls in the Bay of Bengal [16, 17, 26]. Birbhum district formerly had abundant vegetation and forests from which the name Birbhum originates [19, 20]. At that time the number of people was relatively less, due to which there were not so many settlements along the banks of the river [21]. People gradually started to cut forests and make agricultural land for cultivation. But due to the increase in the amount of cultivated land, there is a shortage of water required for agricultural work. To alleviate such water scarcity for agricultural purposes the Mayurakshi River Scheme was formulated during the British period. Later the Mayurakshi project was implemented in independent India. People are now not only farming crops and vegetables by using irrigation water from Mayurakshi but also starts plantation of Eucalyptus and Sonajhuri (Acacia) for pole and firewood though Mahua tree is common in the forest patches till existing in this district [21–25]. In a word, the influence of Mayurakshi River on people and society in the district of Birbhum through scientific approach is immense [18]. Impact of such river commons including water quality rating of Mayurakshi–Dwaraka Rivers is the area of study particularly by many researchers in this field.

4.3 Mayurakshi–Babla River Systems Mayurakshi, Kuiya, Bakreshwar, Kopai, Manikarnika, Brahmani, Gambhira, and Dwaraka rivers belong to the Mayurakshi-Babla river systems. The water resources of Mayurakshi River are distributed among these rivers and these rivers are the main tributaries of Ganges-Bhagirathi.

4.3.1 Kopai The Kopai River, also known as the Sal River, is a tributary of the Mayurakshi River. It flows through Santiniketan, Bolpur, Kankalitala and Luvpur in the Birbhum district of West Bengal. It is a small river. However, during the rainy season, this river causes floods in its surrounding areas. The color of the soil in this river basin is red. The small depressions formed by erosion in this soil are known as ditches (Khoai in

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Bengali). In Kopai-Kunur-Ajay River valley, microlithic crystal stones and petrified wood dating to 1250–1000 BC have been found. The bends of this river are very hansuli (girls neck ornaments) shaped.

4.3.2 Kuiya The combined stream of Bakreshwar and Kopai rivers is called Kuiya. After emerging from the hills of the Santhal Parganas, it proceeds in a spiral eastward course across the hot springs. Then in a spiral eastward course, joins the smaller streams like Chandrabhaga etc. in the southern part of Birbhum district. Rising in the eastern hills of Santhal Pargana of Bihar, the Sal River flows northwards after crossing about 52 km and taking the name of Kopai at Kadipur, it joins Bakreshwar River. The combined stream then joins with several smaller streams and discharges into the Mayurakshi River in Birbhum district taking the name of Kuiya.

4.3.3 Dwaraka Dwaraka or Babla River is a narrow stream. There is no water in these rivers throughout the year except during the monsoon [21]. Originating from the Ramgarh Hills in Chotanagpur, Bihar, it traverses less than 70 km through Birbhum district and the flow of Gambhira, Ghoramara etc. has met. It flows first eastwards and then southwards and joins the combined streams of Mayurakshi and Kuiya at the Hijal Bill in Murshidabad district and emanating into Bhagirathi.

4.4 Catchment Areas Total catchment areas of the Mayurakshi-Babla river systems till discharge at Bhagirathi, is about 11,655 km2 which can be subdivided into six consecutive catchment subareas as the following: (i) (ii) (iii) (iv) (v) (vi)

Upstream areas above Massanjore Dam—1860 km2 Areas from Massanjore Dam to Tilpara Barrage—1349 km2 Areas from Tilpara to meeting with Babla—1900 km2 Brahmani-Dwaraka—3446 km2 Pagla-Bansloi—2200 km2 A minor part included in Bhagirathi—900 km2 .

4.6 Shifting of River Course

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4.5 Flood Situations Before the Mayurakshi project implementation, the Mayurakshi catchment areas had no significant signs of large-scale flooding. Of these, only 1787 and 1902 are known to have experienced major floods in the region. However, Kandi, Barhnya and Bharatpur etc. have large-scale floods in different years. These areas are, however, downstream of Massanjore Dam. Massanjore Dam controls only 1860 km2 out of the total basin area of 11,655 km2 comprising the total catchment area of Kopai, Bakreswar, Mayurakshi, Dwaraka, Brahmani, and their innumerable tributaries and distributaries that drain the waters in Hijal Bil and other water bodies of Kandi subdivision, Murshidabad district. From this it is easily assumed that if all the flow upstream of Massanjore dam could be stored in the reservoir, however, its impact is negligible compared to the basin as a whole. It is probably for this reason that no reservoir has been provided for flooding in the Mayurakshi project reservoir.

4.6 Shifting of River Course Finding the source of the river is very ironic. However, everyone is interested in finding out. Because the flow of the river does not only make the crops green, it also provides the location of past stage arrays. Mayuri or Mayurakshi is such a forgotten river of North Rarh in the Bengal Basin. As can be seen in the ancient maps of Bengal, Mayurakshi River had a companion river at that time. The river emanates from the mountains of Kajangal and joins the Mayurakshi near the town of Karnasubarna. Then the two companion rivers went a little south together and merged with the stream of Bhagirathi. The second river is no more. Maybe the river has dried up. Maybe it has been released in another sector under another name. Its old name has also been erased from people’s memory. But the name of this river before the thirteenth century is estimated to be Mayuri, colloquially as Mauri. Karnasubarna, the then prosperous capital of Gaur Bengal, was situated at the confluence of the Mayurakshi, Mauri and Bhagirathi rivers. River Mayurakshi still exists today. However, the vast expansion of the sector as described by Hiuen Tsung has been greatly reduced. The main course of the river has also changed a lot. Now Mayurakshi and Karnasubarna take refuge in Bhagirathi’s womb holding Mayuri’s stream in her bosom. Now its flow is already lost in the water of river Dwarka. Then it merges with the flow of Kuiye River. Where Hijal’s Trimohana is formed. After this the Babla River proceeds from this Trimohana (Tamune) along the last part of the ancient course of Mayurakshi. It merges with the Ganges at Kalyanpur on the outskirts of ancient Karnasubarna. Mayurakshi has changed a lot. The Subarnabaluka of Mahabharata; and the Tantragarbha of the Pal and Sen era, this river is now very thin. It breaks into

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two branches near Goda. Baluka (Bele), a fragrant tributary of the past named Subarnabaluka, still flows today. Mayurakshi is still changing. It has been steadily moving south for the past several thousand years. In 1774 the course of More River shown by Mr. Renell in his map, Mayurakshi flows north-eastward by Mahalandi Gokarna near Kandi sub-division. But even then, it used to outfall into the Ganga. Its estuary was the horseshoe-shaped riverbed of the Ganga south of Kasimbazar. In other words, in the last 250 years, the last part of the river flow has moved about 23 km to the southwest. Part of Mayurakshi’s abandoned past course is sometimes known as Kana Mayurakshi and sometimes as More River. Yet there is Mayurakshi. Even today it is the lifeline of North Rarh in the endless game of destruction of its own course. But where are its little friends of thirteen hundred years ago or where being Mayuri of late. The path to finding the answer is very puzzling. In this context the name of a village is very significant. Morgram is an infamous village in Murshidabad. In the past it was known as Mayurgram. Interestingly, most of the Mor named places or rivers in Murshidabad bear symbolic memories of their past relationship with Mayurakshi. In some places Mayurakshi is also known as ‘Majher Nadi’. But Mayurakshi is far from this Morgram. Even in ancient maps, no flow of Mayurakshi is known here. Noteworthy is that the course of the river is roughly along the northwest direction of Karnasubarna. Not only that, the line of villages on either side of the river is lost in the rocky red clay country of Birbhum along the north-west line of Karnasubarna. Modern maps show that many areas along the course of the river are still sparsely forested. This river flows like a thin line in the dense forest. Perhaps this river is Mayurakshi’s now-neglected companion river Mayuri. The distance to the nearest village is sometimes more than 10 km. It is believed to be the last trace of the upper course of the Mayuri or Mauri River. The downstream course of the river after Morgram is quite different. From Morgram the Mayuri travels roughly south-east and approaches and divides into two parts. A branch then splits into another two branches. Both branches are lost in the aquifers near Sagardighi. The second branch then flows upwards to join the Dwarka River a little north of Nirol Bill. Probably the last part of the Dwarka River’s course since Nirol Bill is actually the former part of the Mayuri river’s downstream flow. The main problem in determining the course of Mayuri is that the continuity of the course of the river is broken at many places. Once a stream ended in a vast wilderness of red clay. Again, far away along that stretch, the river reappeared at some point under a different name or often without a name. Another piece of information comes from the unclear flow path. That is, this river originates from Trikoot mountain in Deoghar. It is to be noted that Mayurakshi’s source is also in the Trikut mountain. It is roughly understood that Mayurakshi and Mayuri used to carry water in the rough land of North Rarh and surrendered to Ganga near Karnasubarna. Later, when there was a long period of rainlessness (probably during the Pal era), these two rivers along with the Brahmani, Kuiye, and Dwarka, became low-flowing. Settlements were also developed at relatively higher elevations within the river basin. And the entire lowland area near the mouths of these rivers also becomes a unified field. Later,

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when there is heavy rain, the large lowland takes the form of a lake from which a fresh stream flows in the opposite direction to separate branches of these rivers. Its name is Bapla or Babla River. Water flows from Babla or Bapla into Mayurakshi and other rivers. But by that time the lower course of the weak Mayuri had disappeared in the Dwarka and Brahmani basins. Therefore, the rest of the water of Babla flows into the confluence of these two rivers near Nirol Bill. And the upper part of Mayuri hides itself in the form of a few isolated regional streams and flows in the sparsely forested path of Rarh and Kajangal. The three rivers Kuiye, Mayurakshi and Dagra of Rarh flow slowly on the path towards Hijal Bill. Dagra is the combined stream of Dwarka and Brahmani rivers. All three are united either in Trimohana or Tamune watershed. Many waves of history have crashed in the river basin of North Rarh surrounding Hijal Bill over the ages. But Hijal remains as lonely and elusive as the island itself. The flow of the river is not only accompanied by the sound of water; the endless words of ancient times are also mixed. Especially if that river is again the Mayurakshi of ancient civilization, there is no question. They are forever engrossed in the game of constant change of pace and subversion. Mayurakshi is no exception. Even today, several riverbeds are scattered in many parts of North Rarh as traces of its past playgrounds. The touch of monsoon water brings life to that sector. Again, the greyness of the dew season swallowed the river course easily. The name of this sector is sometimes Kana River; Sometimes named Bele River; Sometimes Kana Mayurakshi. According to the evidence of Mahabharata, Mayurakshi was known as Subarnabaluka in the past. Perhaps the name ‘Bele’ comes from Subarna–’Baluka’. Even in the depths of these abandoned sectors, there is a lot of history and many legends hidden. Even today, the magic of that story fascinates some villages of North Rarh. The spread of all the ancient famous ranges of Uttara Raja was consistent with the flow of the Bhagirathi. The northern route followed the southern course of the Ganges and reached Tamralipta in South Bengal through the western side of the Bhagirathi. So, it can be said that Ganga and Bhagirathi defined the two limits of this region. The southern limit remains. Among the rivers of Northern India only the Mayurakshi and Mayuri streams flowed just south of the Ganges in the past.

4.7 River Commons The Mayurakshi River project was implemented through scientific planning and development for human welfare keeping the main objective of irrigation in the farming land and was completed in 1955 at a cost of about 2046 lakh rupees. Rivers using water resources for this project include Mayurakshi, Kuiya, Bakreswar, Kopai, Manikarnika, Brahmani, Gambhira, and Dwaraka. In this project, a dam and reservoir in the Mayurakshi River at Massanjore on the Archean terrain rock of Dumka Hills in Santhal Pargana district of Jharkhand had been constructed. On this river lies the main barrage of Tilpara, 30 km below Massanjore Dam. One of the two main canal systems here is the north-facing canal or the Mayurakshi-Dwaraka main canal and the other is the south-facing canal or Mayurakshi-Bakreshwar main canal.

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The elevation of the terrain along the banks of the Mayurakshi river near the dam is 91.44 m above sea level. The height at Tilpara is 61 m below the contour line and the barrage rises to about 6.5 m. As a result, it is not possible to supply irrigation water to places higher than 67.5 m through the Mayurakshi canal system. Besides, there are separate barrages on the Kopai, Dwaraka, and Brahmani rivers. Brahmani, Kopai, and Dwaraka barrages are located in Baidara, Kultar, and Deocha areas respectively. One barrage is connected to the next by a canal. The canal on the banks of Dwaraka Barrage is named Dwaraka-Brahmani Main Canal. The canal on the left bank of Brahmani Barrage is the Brahmani-North main canal. Apart from the barrages, a large number of small and large canals have been built on the canals, connecting canals, cross-drainage etc. and their number is about 1880. As a result, the entire canal system resembles the branches of a tree. Birbhum is the most irrigated district under Mayurakshi Irrigation Scheme. Of the total irrigated area, 72% is in Birbhum, 22% in Murshidabad, and 6% in Purba Bardhaman district.

4.8 River Water Characteristics 4.8.1 Total Suspended Solids One good lesson people learn from water is that people can adapt to any situation everywhere like water. But the most important thing is to be able to find their flow path. Still these people throw the waste materials knowingly into water by which the river gets polluted, enhancing suspended solids, dissolved solids, and fixed solids in the river water [28]. When a filter is retained with total materials during analysis, the weight of the matter in the filter is considered to be total suspended solids (TSS). A fixed range of total suspended solids is not yet prescribed by the concerned authority like WHO or CPCB for its permissible limit for domestic uses like drinking or outdoor bathing. Total suspended solid is directly correlated with the light penetration. Higher values of total suspended solids can reduce the depth of light penetration within the river. But total suspended solids of river water should not be so high which results in a reduction of light penetration up to 10 percent or more. Mainly runoffs during huge precipitation accelerate the concentration of total suspended solids. The present trend of riverside urbanization causes drastic soil erosion that increases the content of total suspended solids in the river water [31]. Apart from urbanization and soil erosion, agricultural runoff is another factor that increases the content of total suspended solids in river water [29]. As a whole, land use pattern is associated for assisting the occurrences of total suspended solids in the river water. Total suspended solids in river water consist mainly of sediments, organic matters, agricultural runoffs, and other materials. A huge amount of total suspended solids can change the turbidity of river water. Total suspended solids (TSS) of surface water samples of Mayurakshi River at Suri varies from 8 to 70 mg/l where total dissolved solid (TDS) ranges from 74 to 120 mg/l, and total fixed solid (TFS) varies from 48 to 92 mg/l [1].

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Dredging is another cause for the enhancement of total suspended solids in the river water [32]. Dredging should be carried out in the shallow region of the channel and dredged silt is to be carried to the nearest deep pocket when it is necessary to be dumped. The depth of the channel and the deep pocket should be regularly monitored by the river and waterways department under the Government of West Bengal. Though there is no scientific consensus between dredging and riverbank erosion, no dredging activity should be operated along or near the riverbank facing erosion.

4.8.2 Total Alkalinity and Hardness Climate change due to global warming may be indicated by the changes in alkalinity of river water as the total alkalinity is potentially sensitive to the temperature. Alkalinity also controls the pH levels of river water day by day. The photosynthesis by the algae and other aquatic plants enhances the pH level by using hydrogen of the river water and decreases the values of pH when such aquatic plants and the algal population consume oxygen for their respiration and decomposition [3]. Though the permissible limit for the alkalinity has not been prescribed either by WHO or CPCB, it is positively correlated with hardness of the river water because calcium carbonate is considered as the main source of total hardness and is also expressed as CaCO3 . Alkalinity is considered as a measurement of capability for neutralization of acid in the river water [27]. River water shows the values of alkalinity only when the sufficiency of excessive dissolved solids, total hardness, and comparatively higher pH values exist in the river water samples. River water with high alkalinity becomes tasteless and unpleasant for drinking or other domestic uses. As the carbonate content is important for the analysis of total alkalinity, the concentration of alkalinity is determined as CaCO3 in mg/l. Flow velocity of the river water can change the total alkalinity levels [10]. River water with high velocity shows low alkalinity levels whereas low flowing condition results comparatively higher alkalinity levels in the river water [30]. Total alkalinity of surface water samples of Mayurakshi River at Suri varies from 64 to 82 mg/l where total hardness as CaCO3 ranges from 62 to 90 mg/l, and pH level varies from 7.18 to 8.3 in the surface water samples of Mayurakshi River at Suri of Birbhum district [1].

4.9 Water Quality Rating The Central Pollution Control Board (CPCB) has removed Mayurakshi River from the list of polluted rivers due to good water quality [1, 2, 4]. The water quality of Mayurakshi River is 100% good but the water quality of its tributary Dwarka is quite poor (Table 4.1). At Tarapith area, surface water condition of Dwaraka River, a tributary of Mayurakshi River is 46% good, 29% fair and 25% poor as per water

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Table 4.1 Water quality indices of the surface water samples of Mayurakshi-Dwaraka river systems Name of the Sampling Year rivers stations Mayurakshi Suri

Dwaraka

Satighat, Tarapith

Sadhak Bamdeb Ghat, Tarapith

Pre-monsoon

Monsoon

Min

Max

Min

Post-monsoon

2013–14 36.32 (Good)

41.14 (Good)

28.35 35.99 25.87 (Good) (Good) (Good)

28.79 (Good)

2014–15 33.65 (Good)

40.93 (Good)

28.27 33.52 32.24 (Good) (Good) (Good)

38.28 (Good)

2013–14 35.01 (Good)

67.08 (Poor)

31.35 90.1 (Good) (Poor)

47.87 (Fair)

49.04 (Fair)

2014–15 38.24 (Good)

83.78 (Poor)

28.08 37.45 50.68 (Good) (Good) (Fair)

59.53 (Fair)

2013–14 38.36 (Good)

81.11 (Poor)

30.53 53.84 (Good) (Fair)

50.94 (Fair)

2014–15 38.15 (Good)

114.18 (Poor)

32.36 41.56 53.95 (Good) (Good) (Fair)

Max

Min

31.62 (Good)

Max

108.94 (Poor)

Water quality rating: WQI 0–45 = Good; 45–60 = Fair; > 60 = Poor

quality rating based on computed values of water quality indices (Table 4.1). A large number of people from various districts of West Bengal throng the Tarapith every day at the temple of Goddess Kali which is famous for Sadhak Bamakhyapa. Tarapith is located on the bank of the river Dwaraka. So many devotees bathe in the river Dwaraka every day and after puja throw all the things used for worshiping goddess including flowers into the river water. So much organic and inorganic matter is digested in the water of river Dwaraka where there is very little water in the riverbed except during monsoon [5, 7]. Besides, there is a crematorium for cremation of dead bodies not far from the temple. After cremation, the ashes are thrown into the Dwaraka River. Surface water of both Sati Ghat and Sadhak Bamdeb Ghat of river Dwaraka at Tarapith got polluted from such waste materials thrown from the non-point sources into the river water [6, 9, 14]. The biochemical oxygen demand values are within the permissible limit for the surface waters of Mayurakshi River whereas concentration of biochemical oxygen demand is 5.7 mg/l for the river water of Dwaraka which is much above than the limit of 3 mg/l as prescribed by the Central Pollution Control Board [11, 14, 15].

4.10 Summary The load-carrying capacity of the Mayurakshi and its tributaries has decreased due to the reduced velocity of the water flow. Hence these rivers accrete the excess load of their carrying capacity in the riverbed. Sedimentation in the riverbed is directly related to the decrease in water quantity [12, 13]. Most of the course of the Mayurakshi and its tributaries passes through Birbhum district where the average annual rainfall is very low. Moreover, as these rivers flow through areas formed by porous rocks like

References

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sandstones, the volume of water decreases. Mayurakshi River is composed of one type of rock in its upper course and another type of rock in its middle and lower course, reducing the slope of the river which accelerates the rate of sedimentation in the riverbed. The rate of deposition of sediments of these rivers increases due to the very meandering course which creates the point bar on the concave side of the riverbanks. As the velocity and volume of water decreases, the amount of material carried by the Mayurakshi River increases, which helps deposit silt on the riverbed. Moreover, the load of the river where the tributaries join the Mayurakshi river becomes more than the carrying capacity of the main river. Apart from this, the river is unable to remove the sediments due to the excess of silt compared to the velocity of water currents and water volume of Mayurakshi. Due to these reasons, the flow of Mayurakshi River is gradually weakening though the quality of the river water is good and satisfactory. The water holding capacity of Mayurakshi River has decreased for natural reasons, but forest has been lost from the banks of the river due to man-made causes [8]. Although the forest has almost disappeared from both banks of the Mayurakshi River, the herbs and bushes that grow at the whim of nature on the banks of the river, there are various medicinal plants that grow there.

References 1. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 2. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 3. Chattopadhyay B, Datta S, Chatterjee A, Mukhopadhyay SK (2001) The environmental impact of waste chromium of tannery agglomerates in the east Calcutta wetland ecosystem. J Soc Leather Tech Chem 84:94–100 4. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi 110032, p 94 5. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 6. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 7. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 8. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 9. Das GK, Datta S, Sanyal SK (2004) Need for Geomorphic mapping in terms of physicochemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 10. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19

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11. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9 12. Das GK (2011) Impact of salinity and nutrients on the changing mangrove floristic—a case study from the river flood plains of Sunderbans, India (119–129). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 13. Das GK (2011) Studies on the potentiality of medicinal applications of some mangroves of Sunderbans (68–73). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 14. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 15. Das GK (2014) Environmental scenario of Sunderbans: planning and management (1–24). In: Anthropecology and applied biodiversity. OmniScriptum GmbH & Co. KG, Saarbrucken, Germany, p 408 16. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN 978-3-319-11342-5 17. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN 978-3-319-44190-0 18. Das GK (2019) Medicinal plants around wetlands in Sunderbans. Frontier 1–3 19. Das GK (2020) Forest covers of West Bengal: a district wise review. Reason Tech J XIX:26–63. https://doi.org/10.21843/reas/2020/26-63/209272 20. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1 21. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 22. Das GK (2022) Mahua tree and its products. Indian Sci Cruiser 36(4):11–12 23. Das GK (2022) Interference in the Elephant corridor: its effect and mitigation. Indian Sci Cruiser 36(4):13 24. Das GK (2022) Eucalyptus plantation in Badlands. Indian Sci Cruiser 36(2):8–9 25. Das GK (2022) Environmental feasibility test for eucalyptus plantation applying statistical methods. Indian Sci Cruiser 36(2):52–53 26. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 27. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 28. Ewing GN (1985) Instrumental method of chemical analysis. McGraw Hill Book Company, New York, p 624. ISBN 978-0070198517 29. Fierro P, Bertran C, Tapia J, Hauenstein E, Pena-Cortes F, Vergara C, Cerna C, Vargas-Chacoff L (2017) Effects of local land-use on riparian vegetation, water quality, and the functional organization of macroinvertebrate assemblages. Sci Total Environ 609:724–734. https://doi. org/10.1016/j.scitotenv.2017.07.197 30. Soulsby C, Tetzlaff D, Van Den Bedem N, Malcolm IA, Bacon PJ, Youngson AF (2007) Inferring groundwater influences on surface water in montane catchments from hydrochemical surveys of springs and streamwaters. J Hydrol 333(2–4):199–213. https://doi.org/10.1016/j. jhydrol.2006.08.016 31. Tuset J, Vericat D, Batalla RJ (2016) Rainfall, runoff and sediment transport in a Mediterranean mountainous catchment. Sci Total Environ 540:114–132. https://doi.org/10.1016/j.scitotenv. 2015.07.075 32. Zhang S, Zhou Q, Xu D, Lin J, Cheng S, Wu Z (2010) Effects of sediment dredging on water quality and zooplankton community structure in a shallow of eutrophic lake. J Environ Sci 22(2):218–224. https://doi.org/10.1016/S1001-0742(09)60096-6

Chapter 5

Water Quality Rating of Damodar River

Abstract The Damodar River was once known as the sorrow of Bengal due to the loss of life and property caused by the floods in almost every monsoon. Since the middle of the twentieth century, the Damodar River has been blocked by dams and barrages, and after then the river course has not been changed. The water available from the reservoir of the dam has improved the scenario of agricultural advancement in several districts of the Damodar Valley. Around Damodar, the river basin has a lot of badlands where there is no cultivation. The government forest department is succeeding in planting eucalyptus on such badlands. Natural forests in Damodar valley have gradually been encroached upon by humans. Among a few scattered forest patches, the forest covering the entire Susunia Hills in Damodar basin is important for its species diversity of floral assemblages. Along the river course of Damodar, the main industrial area of West Bengal has developed. Though the sewage effluent from such industries empties into the Damodar River after treatment, the water of Damodar River is unfit for use even for outdoor bathing due to the presence of innumerable faecal coliform bacteria and higher values of biochemical oxygen demand in the river water exceeding the permissible limit. Of late Damodar river water is probably polluted by the mixing of the surface runoffs from the non-point sources. Keywords Damodar Valley Corporation · Dams and barrages · Barakar · Mahua · Susunia Hills · Water quality rating · Eucalyptus plantation

5.1 Damodar River Course Damodar, once a well-known river for flooding in Bengal, comes out of the plateau, cut through the rocks upstream. The middle stretch of the river flows through the Chotanagpur plateau hills and then meanders around low-lying areas. The Damodar River flows downstream in the southeast direction and ultimately joins Hooghly River [28]. Exploiting these landforms, construction of dams and barrages in small areas, and successfully planned reservoirs, are the feats of modern science assiduous people [23]. However, due to the presence of steep rocks, people have been able to exploit

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_5

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such an opportunity by the construction of dams upstream of the Damodar River, where the range of width of the river is relatively less. The river is wide in the middle course, and the banks are raised in Purba Bardhaman and Paschim Bardhaman due to frequent flooding, and for this reason, another name of this river is the ‘Sorrow of Bengal’. However, it becomes a narrow channel in the Howrah district, downstream of the Damodar River, where it finally empties into the Hooghly River. Even a dam was constructed before the confluence at Garchumuk, with fifty-eight sluice gates, hence the name Atanna Gate is popular with the locals. For the construction of many such dams, Bengal’s sorrowful slander may have sunk, but the Damodar, the river, has lost its identity as a ravager during monsoon. Now it is no longer so fierce. Dams and barrages on Damodar and its main tributary Barakar like Tenughat Dam, Maithon Dam, Konar Dam, Panchet Dam, Durgapur Barrage, Atanna Gate, stopping the thundering of Damodar in succession, the Hooghly dancing with that terrible Damodar, in the well-defined tune of the people, finally meet in the sea [28]. Impact of such barrages followed by the afforestation programme and natural vegetation along with the determination of the water quality rating in the industrial belt around the Damodar valley is the relevant field of study and research.

5.2 Shifting of River Course The constant changes in the course of the Damodar River and its tributaries have caused the geographical and topographic transformation of Purba Bardhaman, Paschim Bardhaman, Hooghly, and Howrah districts. The old course of this river has gone from inactive to later extinct. At the same time, the once abandoned riverbed has been filled with water and has regained the lost form of the river. Researchers believe that the Damodar once flowed through the riverbed of Banka in the recent past. Banka is one of the ancient courses of the Damodar River which flowed alternately into the Kunti and Kans Damodar Rivers. According to Renell’s map, Banka comes out of the Damodar River and joins the Khari. Again, according to Valentine’s map, a river coming out from the Damodar River joins the river Bhagirathi near Ambika Kalna. From this evidence it can be said that some part of Damodar River once flowed through the course of Banka. Remnants of the old course of the Damodar River are now the Behula River. Behula River bifurcates to form Behula and Gangur rivers. Behula River joins the Mandal Ghat River near Nayasarai and Gangur outfalls into Hooghly near Somra. Behula was once a large river which was so navigable that cargo boats used to ply through this river to import and export goods. According to the old maps, in the seventeenth and eighteenth century Gangur-Behula and Kana Kunti rivers are the two main courses of the Damodar River with their confluence at Kalna and Nayasarai respectively. But in course of time these two rivers were deprived of the flow of the Damodar River. According to Blaev’s Map (1650), the Damodar flows through an ancient important river to join the Hooghly River at Nayasarai, about 5 km north of Tribeni. Traces of at least three rivers can be observed in this Nayasarai. In the riverbed of one of these

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abandoned rivers, an old river flowed and joined the river Bhagirathi. According to Gastald’s Map (1561), another important tributary of the Damodar River is the Kunti River, which joins the Ganges of the Satgaon. Gangur and Kunti, two old tributaries of the Damodar, diverge and outfall into Bhagirathi at Kalna at 25 km upper reaches of Tribeni and Nayasrai at 5 km upper reaches respectively. As a result, the supply of fresh water to the river Saraswati was cut off. Gradually, the Satgaon port fell into disrepair due to the accumulation of huge amounts of silt at the head of the Saraswati River. Practically since then the port of Satgaon has disappeared. According to De Barros, in the sixteenth century the mainstream of the Damodar flowed through the riverbed of the now abandoned Kana Damodar. According to a map of 1690 AD, Kana Damodar was then a large river. Kana Damodar is depicted as a narrow channel in a map of 1760 AD. Later, Renell’s map shows the Kana Damodar as an unimportant and insignificant river. Near the mouth, Kana Damodar bifurcates into two branches to form a large island. One of these two branches is now called Sijberia Channel and the other is Chakkasi Channel. Several years ago, the Damodar River was a narrow channel called the Mandal Ghat River. Later, due to sedimentation, the river lost its normal flow very quickly. As the Kana Damodar River began to decline in importance, the Mandal Ghat River gradually assumed the form of the main course of the Damodar River. For nearly three centuries (1550–1850 AD), severe floods, excess water load, and hence the impetuous flow of the Damodar, caused the repeated course of the Damodar River and since then, humans and their activities have been responsible for changing the course of the river. Even if the natural movement of the river is blocked by dams and barrages, in natural disasters, when the water in the reservoirs of dams and barrages overflows, the water without reservoirs and the heavy monsoon water will cause a terrible flow of the river, resulting in floods, and at such times the river can choose its easy riverbed. As a result, the course of the river changes. The Damodar River is no exception, but even though Damodar is obstructed by dams and barrages, there is no evidence of a major change in its course. Although flooding is a different story from the Damodar of those days when it was not fettered, when no barriers were removed across its course, then in just twenty years the riverbed of its course changed. The river Damodar flows in its lower course along the banks of Gangur and Behula, and Damodar self-surrender in the Hooghly River, near Kalna (1640 AD), exactly twenty years after that, the Damodar’s course changes, the movement is then in the Amta channel, its name is Mandalghat River, in the form of only one channel (1660 AD), and eventually joins the Hooghly River at Garchumuk in Howrah district. Even earlier, the course of this Damodar through the Kana Damodar is shown in De Barros’ map, published in 1550. At that time the Kana Damodar was a wide canal, and on the charts of 1720 and 1730 a narrow channel.

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5.3 Damodar River System Damodar River flows through the Indian states of Jharkhand and West Bengal. The riverbed is rich in resources. The river has formed a large basin where large mines and industrial centers have developed. Earlier this Damodar River was called ‘Sorrow of Bengal’. Damodar is a tributary of Hooghly, a branch of the Ganges. Source of the river is the high mountain peak near Tori in Palamau district under Chotanagpur plateau in the state of Jharkhand, India. The length of the Damodar River is about 592 km. The estuary of the river is at Garchumuk of Howrah district, about 50 km from Kolkata, where Damodar joins with the Hooghly River in the south. Damodar flowing at a spiral speed covers 24,235 km2 of basin areas. The vast basin covers most of Palamau, Hazaribagh, Koderma, Giridi, Dhanbad, Bokaro, Chatra districts of Jharkhand state, Paschim Bardhaman, Purba Bardhaman, and Hooghly districts of West Bengal state. Palamau, Ranchi, Lohardaga, and Dumka districts of Jharkhand and small parts of Bankura, Purulia, and Howrah districts of West Bengal are also part of the Damodar Valley. Barakar is the main tributary of Damodar.

5.4 Barakar The Barakar River originates in the Padma area near Hazaribagh district of Jharkhand. It then flows 225 km through the northern part of the Chotanagpur plateau, passing through Birbhum and Paschim Bardhaman districts of West Bengal to join the Damodar River near Dishergarh. In total, the catchment area of this river from west to east is 6159 km2 . It is the main tributary of Damodar River. The two main tributaries of Barakar river are Ushri (from south) and Barsotti (from north) rivers. The Barakar River is also fed by the water of 15 other small and big tributaries.

5.5 Damodar Valley Corporation Damodar Valley Corporation (DVC) is India’s first multipurpose river valley project. This corporation was established on July 7, 1948, by an Act of the Indian Constituent Assembly (Act No. XIV of 1948). The project was initiated by the then Prime Minister of India Jawaharlal Nehru, the then Chief Minister of West Bengal Dr. Bidhan Chandra Roy and the then Chief Minister of Bihar Shri Krishna Sinha. In 1953, a dam was constructed on Barakar River, a tributary of Damodar River, at Tilaiya under the project. In 1955, the second dam was constructed on the Konar River, another tributary of the Damodar at Konar. Two more dams were constructed on the Barakar River at Maithon in 1957 and on the Damodar River at Panchet in 1959. All these four dams are major dams under the control of DVC. In 1955, Durgapur Barrage was built on Damodar River in Durgapur (Fig. 5.1). This barrage

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supplies water to other canals and rivers on both sides of the river. In 1978 the then Bihar government (presently Jharkhand) constructed a dam at Tenughat outside the control of the DVC. There are hydroelectric generating stations at Tilaiya, Maithon and Panchet. Maithon is India’s first underground hydroelectric generating station. DVC also has thermal generating stations at Bokaro, Chandrapura, Durgapur and Mejia. Entire parts of Hazaribagh, Koderma, Giridi, Chhatra, Dhanbad and Bokaro districts of Jharkhand in the Upper Damodar Valley and part of Palamau, Ranchi, Lohardaga and Dumka districts and entire parts of Purba Bardhaman, Paschim Bardhaman and Hooghly districts of West Bengal in the Lower Damodar Valley and part of Purulia, Bankura and Howrah districts are under DVC scheme. The total area of this region is 24,235 km2 . Initially the main objectives of DVC were flood control, irrigation, power generation and supply, environmental conservation, afforestation and socio-economic upliftment of the people living in the areas covered by DVC projects. Although power generation has gained more importance in DVC in the past few decades, the important contribution of this organization in flood control and irrigation is also undeniable. Among all such planning and developments, afforestation in the badlands around Damodar valley by the concerned departments of the government is an important effort which continues to help in maintaining the ecological balance between environments and industrial areas across the Damodar Valley.

Fig. 5.1 Durgapur Barrage over Damodar River in Paschim Bardhaman district. Note the reservoir water is almost covered with the water hyacinth

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5.6 Impact of Dams and Barrages Even now, when the monsoon water becomes overflown, the black terribly watered Damodar swells somewhere, or the water flow is blocked and whirls like a beautiful wheel, even if only a little win the hearts of the inhabitants of the basin with the song of youth. Itinerant peddlers chose the river as the subject of prose poetry. On the canvas of nature, the Damodar appears in the scratch of the paint, sometimes a stream full of water, somewhere else a handful of sun shining on the sand, sometimes the invitation of a flower, sometimes the entertainment of sparrows, all in all from the stagnant Damodar to all the doors of nature, and for those people who see it, but the constructions of dams and barrages have stopped its rhythmic flows. All these different forms are enjoyed across the Damodar Valley in different seasons throughout the year. A whirlpool of monsoon water fills up the river body after a dry summer. If the rain is heavy, the water overflows on both sides. With the excess water of the dam, the autumn leaves sometimes shake their heads and call for the coming light, the Kojagori (night of worshiping goddess Lakshmi) moonlight shines on the sand. Hemantika (dew season) cannot hide the pain of the darkness, keeps the lamp burning in the boat of the Damodar at night, while the fishermen go in search of fish carrying the burden of pollution through winter. Yet spring comes, like new leaves on fallen trees, getting used to that life cycle again. Dam bends lose nothing, days, time, feelings associated with it, happiness, sadness, which are not written in the pages of history, remain in life and water flow. Still in doubt, if someone wants to see Damodar in Burdwan very closely and get access to a convenient place, near the bridge, where the terrain is very high, and from there to reach Damodar, one has to go down a lot to get its water bodies. The descent is not easy, but the ascent is quite difficult, yet in this uphill and downhill love of Damodar cannot fall. Dam, barrage, and the human society are not able to find a way to resolve the question of good or bad, the inner soul is in danger, the opposite movement of the two entities, the conflict continues in the mind and body. The question is whether continuous dams and barrages on the Damodar River, upstream from the estuary, are to some extent a marriage in human society, though one natural, and the other social. Just as marriage takes away the freedom of a boy or a girl or both, the construction of a dam or barrage on a river is a barbaric obstacle to the free flow of a river, which, if the river were to follow its natural course, might have changed its course from time to time, takes away that right from it. And it is stopped by the modern engineering and technology of man. Damodar is the glory of a little manhood, where even though science has no explanation, he is a man, a river, moreover, like a homeless vagabond, he is also the sorrow of Bengal in the fleet of acquaintances. Even if Damodar is dammed, the course has not changed to the middle or lower course—a question arises. Ganga, Bhagirathi, Hooghly—the same river can be said about them. Dams of rivers and dams of life are nothing, but obstacles are in the way of movement or deprivation of freedom. But life does not stand still, but it affects a

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life, be it water life or human life, even if there is no natural or social barrier. Just one change leads to change in the larger sphere, be it in society or in life. Misery is not the same as being homeless, it seems that happiness is often elusive. Some leave home voluntarily, some break up. Whatever the majesty of man or the beauty of woman, everything changes in the interpretation of relativism. Where once in five years the field would be filled with green due to the silt carried by the river during flood, what else happens, the nature of the muddy water on the ground may go like this again for another five years. If the current does not flow over the river, how will it break its banks, will not create a narrow bend, and the river cannot change its course in such a short period of time. Maybe that sorrow of Bengal is no more today. The flow of water is also much controlled in recent times by the construction of barrages, even if both sides of the river are inundated by flood, it does not leave the love for the crops like a last poem. A picture of everything has been changing. The course of the river, the creation of river-bends, the breaking of the banks, the changes continue for decades, not being caught by the common eye. But still has not changed. Riverside livelihoods are also affected. Villages that are flooded with little rain almost every year, or, in more remote areas, that are rarely flooded, talk to people along the riverbanks to understand the temporal changes in the course of social life. Nothing is seemingly static, everything is changing. The village is floating in water even after damming because of what, just different landforms. They can’t love the harvest of gold. Since the land is no longer fallow, or there is no change in the produce of crops produced by the land from year to year, fallow would solve these two problems at once, and the additional crops will grow in the following year, along with the change in the topography of the low-lying land due to the spreading of the silt. The burden on the riverbed is not light, everything that cannot be carried accumulates gradually, the riverbed, unable to bear the load of a little rain, spreads it all on both sides. The crops are no longer good because of the pollution, polluted things. The natural fertility of the land gradually decreases. In the barn itself or how much returns, again, the attempt to increase the artificial fertility, which is a cause of stress for the common farmer, if we want to bring back normalcy, then the people will say—break the dam, break the barrage. Those who built the barrage decide whether to break it or not. But the farmer never wanted more produce, only that much of the year, for his family, and the rest sold to other family consumers. A peasant never dreamed of becoming a king, though sometimes a political party leader made him a king. But the green colour of the grain field floats in his eyes, he likes the seed spread on the grey soil, he only needs to water it once, that’s it, the seed wakes up in a few days, the seed leaves meet, the seed bed in it, no need to water anymore, the grain or the amount of water required for vegetable cultivation is supplied by the soil, through regular renewal of sufficient groundwater. And its control is in the normal flow of the river, damming the ground water reservoir has stopped at the bottom, enough withdrawal of groundwater, which is still lying, after a few days will come in front of the question mark up to the drinking water reservoir, but what is the crime of those whose villages are not near these river dams.

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The simple rural people of Bengal with few needs are happy with a very simple life. They cultivate with all their heart despite the hardships. Due to socio-economic reasons the size of holdings is getting smaller and smaller, and for this reason, there are many difficulties in the application of agricultural aids. But the relatively distant alluvial lands, except in the riverine tracts, remain in many cases mono-cropped for want of water. And how many people can afford to use groundwater, that people in urban or rural areas are not behind in the use of groundwater. Due to damming of the river to retain water in the upper reaches, the lower reaches remain dry almost throughout the year, what a severe water shortage. Damodar was still sad. But grief is the complete opposite. These are the sorrows of Damodar’s fringes, but the Damodar’s own pain, its own, the sorrow of not having a natural flow, which it does not hide, the cracks in the river’s bed reveal its dryness. Sometimes when the water is released from the dam, or even if the crack is covered by monsoon water, the eddy, depth, and irregular flow of the Damodar River starts to wail from the atrium of the bed. Boating along the course of the river is the pride of any river, but the Damodar River is deprived of it, its only satisfaction being the occasional crossing of the river. Hiding so much pain deep in the bed, the flowing river is choked, breath is taken away. In this situation restoring normality is like a golden stone bowl. Even if the wound of the river is partially healed, the pain never subsides, it is like an endless bowel. The boats of the sailors, the regular crossing of the ferry service is all a thing of the past. During the dry season, a motorcycle ride on a bamboo slat bridge is a witness to everything. When no conditions for rejuvenation are visible, old age is the future. Such Damodar is not practiced less. But seeing Damodar afresh with other eyes, they fall in love again. Attraction, and love are gradually increasing. Not so familiar with upstream of the river, but even at high speed there is beauty in the depth, the expression is in the eye of the beholder. The mesmerizing mid- and low-tempo poets appeal to everyone including literature. And there is an abundance of fish in certain places. No matter how much silty sand from the upstream is deposited in the estuary by the process of erosion, a question may arise—does the river become old at all, the Damodar River is not old, the river is a symbol of youth, when somewhere it is dry and brittle, it is still restless, until man occupies its floodplain. The river is dying only when its stream-like body is dispossessed, not like the mortal body of this man, which is lost forever, but when it has the opportunity to shed water, it becomes youthful and lush again as in the old days. In fact, when the riverbed is seen dry, the politicians start to pay bills, the age of the river is lost in the counting of votes. Land along the banks of the Damodar River, where the modern technology of dams and barrages has developed, now fetches exorbitant prices, as does three-four croplands. Drowning in flood, if the water is released from the barrage, even not every year, such a flood comes, warns DVC authorities, government administration, agriculture director, so there is plenty of time to prepare for artificial flood that accelerates the produce in the ensuing years as witnessed by the farmers. Then the farmers are happy, their heart is filled with satisfaction, because they will not have

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to pay the cost of fertilizers and pesticides for more than five years for the farming land. During the autumn, only the flowers of the reeds, and their sloppy white saffron, stand in the pasture, pristine and unadulterated, where rivers, riverbeds, river floodplains, river basins were—all fall prey to human greed. But the development of civilization once started on the banks of this river. Why only Damodar River, civilization developed on the banks of all rivers. Then people were growing crops with the help of its water. The affinity of rivers is saturated with rural agrarian social life. Again, that river is a victim of human greed, cultivated fields full of monsoons flood the river with life and bring prosperity to the farmer’s family. The youth of the river is tied to the flow and dynamics of its watercourse. But what thirst wakes up, under that river, search in the ocean of pain. Who will do this search, who will do the solution, who will be able to crown success, to restore the youth of the life of the river, the Damodar River will find its answer.

5.7 Natural Vegetation A major part of Damodar valley belongs to Chotanagpur region. The soil of Chotanagpur plateau region is not very fertile. Laterite and red soil dominate in most areas here. Seasonal deciduous plants like Sal, Simul, Palash, Mahua, Teak etc. predominate here. Among these plants, Mahua is not only a favourite tree of the local tribal community, but also its economic importance is immense including its medicinal values.

5.7.1 Mahua and Its Products In the past, there were huge forest areas on both banks of the river Damodar [21]. Now there is no longer that dense forest, there are only some forest patches scattered here and there. Mahua trees are always found in abundance in these forest floors. The tribal community is dependent on the flowers, fruits, and bark of the Mahua tree. Mahua is closely related to the daily life of the tribes. For various reasons, the flames of fire in this Mahua Forest flare up particularly during the spring. Then miles upon miles of forest of Mahua trees were reduced to piles of pure ash [24]. In such risky situations, a herd of elephant comprising about 72 males, females and calves coming from the Dalma Range during July of the last year (2022) are straying this year (2023) in the jungle of the Panchet Division under Damodar valley Corporation [25]. Mahua is loved by tribal people especially the Santal group. In Jungle Mahal, where Mahua is, the tribal community lives, or commutes especially in the commencement of spring. The reason is only one and that is to collect Mahua flowers.

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They make local indigenous liquor called Mahua from it. Men and women of the tribal community celebrate their festival by drinking Mahua. Generally, the women of the tribal community collect the Mahua flowers scattered under the Mahua tree. And in the later period, through various processes, the indigenous liquor called Mahua was made. Mahua (Madhuca longifolia; Madhuca indica) is a large tree. These grow up to 30 to 40 feet tall. Leaves are oval. Stem short. Its flowers are fleshy, light grey in color, and when the plant is in full bloom, the flowers emit an attractive sweet fragrance. The flowers are succulent, and the taste is sweet and sour. The flower extract is intoxicating. Its fruit is oval. Its mature seeds are available between June and July. Its grey bark is about half an inch thick. Betel-shaped fruits are produced in late spring. It ripens between June and July. It is locally known as Mahula, Madhuka, Moha, Mohul, Mahua etc. Although a dry zone tree, it grows well in humid mild climates. All leaves fall in winter. Flowering starts from the age of 10 years. Mahua tree is found all over the Indian subcontinent including Jungle Mahal. Mahua tree has medicinal properties like boiled leaves of Mahua tree cures cough quickly; applying the seed oil of Mahua tree on the throat cures cold problems; Mahua seed oil is beneficial for arthritis pain if the bark of Mahua tree is washed and boiled and this decoction is mixed with milk and consumed regularly in the morning and afternoon; it is beneficial in hemorrhoids; old wounds are healed if Mahua leaves are crushed and applied to the wound; Mahua seed oil is also used as an antivenom on insect bites to reduce the venom; Mahua seed oil is beneficial for headaches and if any part of the body is burnt, applying Mahua seed oil will heal the burn quickly. Mahua flowers are rich in carbohydrates, minerals, vitamins, and calcium. Cooking this flower with rice increases its nutritional value. After sugarcane, mahua flowers are the most important source of wine and vinegar. It is also used as cattle feed. Its flowers and fruits are used as traditional food by tribal people. Its seeds contain 20–50% fatty oil, which can be used in soap making. Mahua seed pods can be applied as fertilizer. Many believe that the smoke from burning Mahua seeds can repel snakes and insects. Tribal people use Mahua Khail (oil cake) to kill fish and treat snake bite. Mahua oil is used as a poultice, cure for skin diseases, rheumatism, headache, laxative, hemorrhoids. Gum is obtained from its seeds. Its husk can be used to make activated carbon. Folklore has it that the bears in the Mahua forest would go crazy on the scent of the Mahua tree. White milk is secreted from the cut place of the milk tree Mahua, the bark is collected from the trunk and used by traditional religious people to make a reddish-brown abir (powder) and use it in festival rituals. Oil is obtained from Mahua seeds. Its wood is very hard. Ground Mahua seed meal (Mahua oil-cake) is used as a natural soil amendment for soil borne disease management in other crops as well as in the water bodies including ponds, lakes, and fisheries. The extract is a favorite drink of the tribals, especially the Santals. Mahua flowers usually fall under the tree in March. But the people of the tribal community have trouble finding the Mahua flowers that fall in the dry winter grass under the trees. So, to eliminate the dry grass around the Mahua tree, a group of tribal people set fire to the scrub in the forest in the dark of night. Perhaps a brush

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fire spread from tree to tree in the forest and gradually turned into a terrible, allconsuming conflagration. It becomes impossible even for the fire brigade to put out such an all-consuming fire. People of the tribal community should be appealed against setting fire by scrubbing the forest floor to clean them. If the tribal people can only be employed on a wage basis to clear the lower part of the Mahua trees, so that they will refrain from setting fire. However, not all places under Mahua trees are filled with grass in the forest areas. In Sonamukhi, Gangajalghati, Beliator, and Jaipur forests of Bankura district, Panagarh, Garh Jungle, Aduria or 14-mile forest, Orgram forest of Paschim Bardhaman district, and Illambazar forest of Birbhum district, grass is not commonly seen under Mahua trees. That is why wild or man-made fires are not heard of in these forests. However, the growth of Dhasna grass on and above the Susunia hills of Bankura district is quite good which makes it difficult to collect Mahua flowers. Dhasna grass looks a bit like a reed. This grass grows to a height of about 2–3 feet due to which the Mahua flowers that fall from the tree are lost in the thickets of grass. To burn this grass, someone might have set fire to dry scrub on and above the Susunia Hills. Apart from Mahua, there are Palas, Sal, Bot, Aswath, Khejur, Aam, Sonajhuri, Eucalyptus, Arjun, Kasai, Haritaki, Bahera, and Adham Charrha trees in Susunia Hills. And in areas where there are no trees at all, mountain climbing training is provided by the Bankura Nature Academy at Susunia Hills. In such a situation, if Mahua trees can be planted around the foothills of Susunia Hills or selectively on 1–3 acres of land surrounding the hills, then the tribal people will get their required Mahua flowers during spring. Mahua trees should be planted by the people of the tribal community living near the Susunia Hills, and they have to take care of the Mahua tree. Then they will no longer go up the hill to collect flowers from the Mahua tree. If the Joint Forest Management Committee arranges for such Mahua plantation programmes in barren land over a large area on either side of the road leading to Susunia Hills, then it seems that the lion’s share of the real problem for torching man-made fire will be solved.

5.7.2 Susunia Hill Dense natural forests of myriad flora cover the Susunia hills. Moreover, a large number of herbs grow in the foothills of these hills, which are used to cure various diseases in the human body. It is strongly believed by many that the springs of the Susunia Hills and the dense forests adjacent to the hills were the grazing grounds of herbivorous animals, as well as for the preying purposes of carnivorous animals. And that is why the people of the Paleolithic and the later Middle, Late and Neolithic people chose this hill as their suitable place to live which is supported by the oldest inscription of West Bengal located on Susunia hill. A small fourth century inscription found at Susunia indicates that Chandra Varman’s capital was the city of Pushkarna, now known as Pokhrana. Pokhrana or Pakhanna is a village under Barjora Police Station in Sadar Subdivision of Bankura District of West Bengal. The village is

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located on the south bank of the Damodar River, about 40 km northeast of Susunia. It is believed that Pushkarna, the capital of Chandra Varman, the son of the ancient Raja Sinhavarman, is actually this Pokharna village. The Susunia inscription of the fourth century mentions this place. According to the Allahabad Prashasti, Samudra Gupta defeated Chandra Varman and incorporated this region into the Gupta Empire. Such historical evidence suggests that the Susunia Hills, located very close to the Damodar River, bear witness to geography and history. Susunia Hill is surrounded by date palms and Palas covered by laterite red soils under its feet. At the foothill of Susunia Hill, there is a pond filled with water from the natural fountain. The pond, covered with lotus blooming round the year, is very important for the existence of a number of medicinal plants grown on its surrounding banks [18]. There are rock mounds here and there, and history is unique in this steep hill where the medicinal herbs are mixed with the trees of plateau origin. Even the oldest script of Bengal carved by the king Chandra Varman can be found here. In recent times, fire burns on Susunia hill, almost every consecutive year particularly when the spring comes after the winter. The bushes on both sides of the rocky curved path were charred by that fire. The vines and bushes of medicinal plants are cleared. Some of the vegetation of the hard standing tree trunks remains unless burned by fire. And then the wood mafia’s sharpened axe started flashing in the moonlight because the activity of felling trees is executed in the darkness of night. Maybe the poachers or wood mafia set fire to the dry leaves lying under the trees to trace the forest path up the Susunia hill. The ups and downs of the hilly path are not discernible as the once it is covered by the fall of winter leaves and looks like a flat surface. There is a possibility of danger in walking or climbing over such leaf-covered passages. The people cannot understand where there may be slopes, ditches, or potholes. If people step in the wrong place on such a path, they will fall to the foot of the hill. Maybe this is how nature teaches poachers or the wood mafia. Moreover, snakes make nests under dry leaves in spring. The female snake builds a playhouse under the dry leaves during the spring. A number of baby snakes were born from the eggs within a few days of their mating. Then they all move around wandering together. Stepping on one of them in the dark may lead to meeting the doorstep of death. The colour of the festival matches the colour of fire. During the spring festival, the forest in and around Susunia hill catches fire. And the fire starts in the darkness of night when no one, particularly the local inhabitants or common people, is on the top or in and around the Susunia hill. Susunia hill burns in the middle of the night in the fire of a burnt cigarette or bidi—it does not seem to want to accept it. In the night there will be people on the top of the Susunia hill who can see the moon from the hilltop smoking a cigarette or bidi. It seems that someone deliberately sets such a fire. Some people may know the culprit who started the fire, but they keep their lips shut, so the source of the fire in the Susunia hill every consecutive year during the spring is still not known. There are about twenty shops, and one or two shops are in each meander along the rocky path at different heights on the way up the Susunia hill. Readymade saltlemon-sugar syrup, tea, water bottle, biscuits, snacks packets, and other dry food items are available in these temporary shops. After consumption of the food items or

5.7 Natural Vegetation

79

drinks, various non-biodegradable packets and plastic glasses including plates and bowls of thermocol origin are thrown on the hill which accelerates the erosion of Susunia hill. Discovery of animal remains of lion and giraffe proves that the forest was not a dense one in and around the Susunia hill in the past i.e., Susunia hilly area was covered with a thin forest because lions prefer thin forest for their easy movement in free space. The present habitat around the Susunia hill is befitted for the lions and giraffes. Further, non-availability of animal remains of tiger in the Susunia hill support the existence of thin forest in the past as the tigers prefer dense forest as their natural habitat. And the lion’s preference for the thin forest is a fact and proved from the recent rigorous survey by the forest officials of Gir National Park in Gujarat. In 2021, a large number of trees ravaged by the devastation of Cyclone Tauktae due to strong wind action has made the Gir National Park comparatively a thin forest which the lions prefer more as reflected from the present survey. Further, this thin forest was advantageous for the preying animals and because of such preying activities by the ancient men on a regular basis had made the large mammals like lions, giraffe, wild buffalo, Bengal cattle, gaur, or bison completely extinct from the Susunia Hills. Present-day tribal inhabitants are now taking similar opportunities to hunt wildlife in such vacant forest lands burnt due to fire of unknown causes in each consecutive year. There is no hand-held evidence of forest burning by wood mafia or tribal people, so these are possible reasons. Apart from these reasons, it cannot be ruled out that local people burn forests every spring for the festival on the top of Susunia hill where food is arranged for many local people and devotees. Every year the forest is set on fire by the local people to roam the vast area on the top of the hill and arrange a festival in the spring, burning the grass and dry leaves and killing snakes and reptiles. This is the most acceptable reason for forest fires in Susunia Hills. Susunia hill, known for its natural spring, lies about 23 km from Bankura town in the Chotanagpur gneissic plateau and has an elevation of about 448 m. The main composition of the Susunia hill is sillimanite and quartzites that contain kyanite. Tourmaline and quartz bearing pegmatite, blue in colour, is found in the field observation within the quartzite rocks in a few square meter areas and the quartzite is the country rock of Susunia hill. Idols of God and goddesses, dishes, bowls, and other household essentials are made mainly from this type of rocks by the local rock carving artists. They collect this rock from the hill to make these idols and household essentials. If the rocks are collected in this way, it will not be possible to compensate for the damage that will occur to the Susunia hill because these rocks are not renewable. There are at least twenty rock carving shops at the foot of Susunia hill. Construction of a large building with several outlets including meeting halls has been made by the state government for training in the art of rock carving. But keeping in mind the environmental health of Susunia hill, the government should reconsider the matter. Otherwise, the lush green appearance with a huge dome like structure of Susunia hill, the rocks of which are comparatively older than the Himalayas, will gradually disappear along with the oldest script of Bengal carved upon the hill wall by the historically famous king Chandra Varman of Pushkarna kingdom. Pushkarna

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5 Water Quality Rating of Damodar River

kingdom is presently known as Pakhanna, a village under Barjora police station in the district of Bankura in West Bengal.

5.7.3 Eucalyptus Plantation in Badlands The amount of fertile land in the Damodar valley is relatively less. Even in Purba Bardhaman district under Damodar valley where crops are grown in abundance, there are a lot of wastelands. Eucalyptus trees are being planted on that bad land under the initiative of the government forest department though Eucalyptus trees extract a lot of ground water for its survival. Not only it reduces the groundwater, but uptakes more soil nutrients, and even the Eucalyptus does not allow other species to grow in and around its plantation site as evidenced on the badlands of Ausgram under Guskara forest range of Bardhaman Forest Division. In and around the Eucalyptus plantation site, other crops or vegetation are not able to produce a good harvest if the Eucalyptus exists nearby, and it is an invasive species [26]. It is a good idea to stop planting Eucalyptus trees to save ground water and support native species. But before ban for its plantation, it is necessary to observe thoroughly if it has any ecological advantages of being ecofriendly to nature for planting them. The study area is a site of Eucalyptus plantation which was undertaken in the badlands under a social forestry scheme by the Forest Department of West Bengal where no other plants grew other than the grasses only about 10 years back. It is now the time to investigate the quality of soil at the plantation site through soil analysis. Afforestation under the social forestry scheme has been somewhat successful since the eighties of the last century on both sides of the national and state highways, canals, and non-metal roadside areas in the rural belt of West Bengal. Such a social forest creation project of the Forest Department includes several parks, sanctuaries, and forests in different districts of the state which are well known to forest lovers and travelers at present. Social forest creation in the urban belt is usually done by planting the trees like Chhatim, Jarul, Kath Badam, Krishna chura, Radha chura, Kadam, Palas, Hijal, Kanak chura, Bakul, Sonajhuri or Akashmani, and Eucalyptus. Although some trees have been cut down by the locals, the remaining trees are still standing by the side of the road. Among these roadside trees grown under the social forestry scheme, the purpose of planting Eucalyptus is due to its rapid growth that attains marketable size within a shorter duration. It is less likely to be consumed as cattle feed because of its peculiar odour. Eucalyptus can grow rapidly even in the barren or badlands, where the growth rate of different species of native trees is quite low. Eucalyptus is cultivated to meet the growing demand for cooking fuel and structures for house building in the rural belt of West Bengal. In a kind of extract in the leaves of all these exotic plants particularly in Eucalyptus, which cattle never want to taste. Therefore, Eucalyptus seedlings do not suffer much damage by the domestic animals in the forest creation or plantation under social forestry scheme either by the government or by the common people in their own land. To increase the areas of the green canopy by tree cover under

5.7 Natural Vegetation

81

the afforestation programme, all these exotic species are generally not so costly to purchase and are convenient for the plantation [27]. Some observations regarding good and bad aspects of Eucalyptus are mentioned as the following.

5.7.3.1

Merits of Eucalyptus Trees

The oil of this tree produces antiseptic and cleanser. They are used to repel mosquitoes. Its leaves contain formylated phloroglucinol which has many medicinal properties. They are necessary in the pharmaceutical industry and paper industry. It grows very fast (can be 15–20 m in 5 years in Australia).

5.7.3.2

Demerits of Eucalyptus Trees

Eucalyptus lowers groundwater levels. It causes problems in irrigation. Absorbs water in and around 10–12 feet areas surrounding its boundary of growth. No other trees or crops can grow around it. Leaves and pollen are harmful to the human body. Birds cannot nest. In the area where this tree is located, it absorbs more water, resulting in desert shape in the area. The mature Eucalyptus plant absorbs about 30 L of water in 24 h and dries the soil. After 10–20 years of planting this tree, other trees cannot grow side by side. Excess carbon-dioxide is emitted which raises the temperature. The leaves do not easily rot in the soil. They contaminate pond water situated near the site of the plantation. The danger of creating wildfires through Eucalyptus is evident from Australia. Its root system goes up to a maximum of several feet deep in the soil etc. People are encouraged to plant more and more trees to prevent global warming and maintain the balance of nature. But that is not to say that all kinds of trees are good for humans. There are also trees that are harmful to the environment, far from being environmentally friendly. Sadly, such species of trees are being planted on a large scale in the land of Bengal. The name of such a tree is Eucalyptus. There are several species of Eucalyptus trees in the world. The scientific name of this plant is Eucalyptus obliqua. Although the Eucalyptus plant has some medicinal properties, it has serious detrimental effects on the environment. Surprisingly, most of the people are not aware of the harmful aspects of this Eucalyptus or they are showing indifference towards it. Many are falling victim to the situation again. They are unknowingly harming themselves. Although the Bangladesh government asked

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5 Water Quality Rating of Damodar River

in 2008 to stop planting and marketing Eucalyptus saplings as a harmful tree, many people are planting saplings of this tree in the hope of making a profit by selling wood in a short time. The benefits of this plant far outweigh its disadvantages. In the state of West Bengal, especially in the districts of North Bengal, its planting is very risky and harmful. In the minds of the people, this tree is also known as the giant tree. Few science-minded people make publicity for the protection of nature from this monster tree, and they suggest destroying this monster tree and planting a fruit tree sapling by replacing the Eucalyptus trees. But the soil scientists show that the Eucalyptus plantation has even direct influence for the improvement of soil quality. As the Eucalyptus plantation results in the improvement of soil characteristics, a roadside Eucalyptus plantation site has been selected for stoichiometry of the soils which was once a void land looking like a desert as a badland before the Eucalyptus plantation about 10 years back. The badland selected for the Eucalyptus plantation by the forest department belongs to the recorded forest area of the government and the plantation has been monitored and managed by the Ausgram forest beat under Guskara range of Bardhaman Forest Division. The badland measures about 10,989 m2 where 37 rows of Eucalyptus saplings were planted, and each row contains 29 trees. The planted trees are now mature and attain 66 feet height on average, having DBH (Diameter at Breast Height) 2.5 ft. along with 1.05 ft. diameter in the middle of the log, and 0.30 ft. diameter on the top. Data of diameters and height are collected from the cyclonic storm-stricken uprooted trees on the floor of the plantation site. From the values of average height and diameter, the volume of a tree is estimated to be 84.88 cubic ft. As the dry weight of 1 cubic ft. Eucalyptus tree is 8.61 kg, total weight of a tree is calculated to be about 730.86 kg, and then total weight obtained for 1073 numbers of trees (37 × 29) in the site of plantation is about 784 tons resulting estimated biomass 392 tons (784 × 0.5) only for the wood logs of Eucalyptus plantation in the badlands. The quantity of estimated biomass reveals the huge sequestration of carbon dioxide from the atmosphere [21]. Further, research on the improvement of the soil quality due to the Eucalyptus tree may infer about its plantations in the badlands in near future which is still in progress. If the quality of soil better the badlands soil substrates by the plantation of Eucalyptus trees, then it should be planted in the badland or wasteland not only because of the improvement of the soil quality in presence of the Eucalyptus plantation comparatively in a shorter duration, but also for the quick harvest and easy availability of huge wood logs within shorter duration in comparison to the other tree species.

5.7.4 Environmental Feasibility Test for Eucalyptus The state forest department planted trees in barren areas of wastelands within the recorded forest areas early in the new millennium. Those trees are now almost turned to maturity but there may be some environmental degradation due to their dense

5.7 Natural Vegetation

83

occurrences. Therefore, the application of statistics by using the Test of goodness of fit is to review the environmental degradation or improvement of the environment in the plantation site. The application of statistics shows that there is no environmental problem, but the growth of trees in barren lands continues to benefit the environment. The outstanding scenario of the Eucalyptus trees in rows planted in the wasteland of recorded forest area nearby Ausgram Forest Beat by the forest department under the control of Guskara Range of Bardhaman Forest Division of West Bengal (Fig. 5.2). This eucalyptus plantation is arranged in a total of 37 rows with 37 trees planted in each row in the wasteland of about 10,989 m2 areas [27]. Despite the care of the forest department, not all the saplings survived. An average of 33 trees are now seen in each row. Some seedlings were eaten by cows and goats of the nearby households, some died due to waterlogging or neglect, and the frequently occurring cyclonic storms also uprooted some mature trees. At present the trees attain 22 m height and 77 cm DBH (Diameter at Breast Height) on average, and the trees are now standing densely. Such a plantation reveals now a dense one after attaining maturity of each tree after their 15 years (approximately) of growth period that requires an environmental feasibility test. The application of statistical methods is important to determine the environmental impact of existing trees at present. As the average distance between the trees at right angles and straight is 3 m, the lack of nutrients in these densely populated trees may have different effects from other physicochemical conditions [19, 22]. Such a situation needs a proper environmental measure befitted for the Eucalyptus plantation. The test of goodness of fit for the determination of the environmental impact of such tree plantation in wasteland under the social forestry scheme will be helpful statistically for the feasibility test of Eucalyptus.

5.7.5 Statistical Computation The statistical formula used for the goodness of fit test is, χ2 =

k  (Oi − E i )2 Ei i=1

where, Oi = Observed frequency in the ith class, E i = Expected frequency in the ith class, k = Number of categories or classes. E=

n T otal o f the obser ved f r equencies = N umber o f gr oups k

The χ2 statistic of equation follows a χ2 —distribution with k-1 degrees of freedom [29].

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5 Water Quality Rating of Damodar River

Fig. 5.2 Eucalyptus plantation site in the recorded forest areas standing nearby Ausgram Forest Beat under Guskara Range of Bardhaman Forest Division in West Bengal

5.7 Natural Vegetation Table 5.1 Number of trees observed in the Eucalyptus plantation site in 2022 at Ausgram Forest Beat of Bardhaman Forest Division

85 Number of rows Observed (O) Expected (E) (O − E)2 /E 1

36

33

0.27

4

35

33

0.12

7

29

33

0.48

10

31

33

0.12

13

35

33

0.12

17

28

33

0.75

20

31

33

0.12

23

34

33

0.03

27

34

33

0.03

30

33

33

0.00

33

36

33

0.27

36

34

33

0.01

12

396

396

2.32

The null hypothesis is stated as the environmental impact in terms of the number of trees that is fit to be arranged environmentally without disturbing nutrient uptake or other physicochemical effects among the trees and derive the expected frequencies in different plantations accordingly [20]. Table 5.1 represents the observed and expected number of trees per row in the Eucalyptus plantation site. For statistical analysis, a number of mature trees with a gap of 3 rows are observed to avoid complicacy in computation (Table 5.1). The calculated χ2 value is 2.32. Entering the χ2 table for (12 − 1) = 11 degrees of freedom and ∝ = 0.05, the critical value of χ2 obtained as 19.7. Therefore, the null hypothesis is accepted, and it is concluded that the number of trees existing in the present arrangements planted under the social forestry scheme is supposed not to be faced by environmental degradation statistically. Eucalyptus is not a native tree, but an invasive one. Usually, other trees do not grow in the area where eucalyptus grows. One such eucalyptus tree is considered for community-based forest creation in almost all the states including West Bengal and union territories of India. But this tree grows very fast attaining heights ranging from 20–25 m only about in a 15-year period, and densely occurred. The application of statistical methods using Test of goodness of fit on the data collected from the plantation site of Eucalyptus trees of society-based forest creation shows that there is no environmental problem in the dense occurrences of these trees planted nearby Ausgram forest beat under Bardhaman Forest Division. The result obtained from the statistical analysis reveals that the plantation site of Eucalyptus trees is environmentally feasible and the present arrangement of existing trees in rows may not have to face any environmental degradation.

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5 Water Quality Rating of Damodar River

5.8 Water Quality Rating Although treated, the level of industrial effluents from the factories standing on the banks of Damodar is below the acceptable level [14, 16, 17]. Municipal wastewater including factory effluents mixed with the water of Damodar River and for this reason water quality has deteriorated [15]. pH ranging from 7.06 to 9.05 indicates alkaline characteristics of the surface waters of Damodar [1–4]. Release of industrial effluents without treatment and mixing of such wastewater with high concentration of metallic compounds in the river water may cause higher values of pH enhancing alkalinity property of the water [11–13]. Water quality improves for both Damodar and Barakar rivers based on biochemical oxygen demand (BOD) values recorded in the Central Pollution Control Board (CPCB) Report 2022. Damodar River featuring Priority IV in the CPCB Report 2018 has now been categorized as Priority V in the report of CPCB 2022. The status of Barakar River remains the same in Priority V and soon the river will be excluded from the list of polluted rivers as the biochemical oxygen demand value goes down from 5.7 mg/l in 2018 to 3.1 mg/l in 2022. The CPCB prescribed standard values of BOD to be 3 mg/l or less to consider a river stretch at least fit for outdoor bathing [5–7]. Surface water condition of Damodar River is 16% good, 55% fair and 29% poor as per water quality rating based on computed values of water quality indices [8–10]. Water quality improves for Barakar River where surface water condition is 66% good and 34% fair as per values of water quality indices (Table 5.2). Not only Barakar, Damodar also has shown improvement in water quality with respect to BOD values as recorded in the CPCB Report [3]. Table 5.2 Water quality indices of the surface water samples of Damodar and Barakar rivers Name of the rivers

Sampling Stations

Year

Damodar

Andal

2013–14

Durgapur Raniganj Barakar

Asansol

Pre-monsoon

Monsoon

Post-monsoon

Min

Max

Min

Max

Min

Max

–

–

–

–

51.02

65.81

2014–15

53.02

60.12

45.74

50.52

45.53

72.08

2013–14

–

–

–

–

50.38

60.18

2014–15

54.26

60.55

35.34

46

57.93

72.59

2013–14

–

–

–

–

52.63

67.53

2014–15

54.55

65.45

34.78

83.82

54.85

67.19

2013–14

43.36

45.98

32.98

52.71

39.6

43.58

2014–15

44.12

47.06

30.59

44.9

42.29

46.5

Water Quality Rating: WQI: 0–45 = Good; 45–60 = Fair; > 60 = Poor

References

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5.9 Summary Damodar River and its basin in a tangle of dams and barrages, and even, a hundred meters away from its estuary, the vast sluice gate has been constructed, called the Atanna Gate, at Garchumuk, Howrah. Dams, barrages, sluice gates, mythological structures etc., have dammed the Damodar River at the bottom. Two tributaries (Barakar and Konar) towards the head of the river, whose waters feed the Damodar, have also been dammed, the Maithon Dam on the Barakar River, and the Konar Dam on the Konar River, although they are part of the Damodar Valley Project under the name of the Damodar Valley Corporation or DVC. Two dams on the main river Damodar are Tenughat Dam and Panchet Dam including a barrage known as Durgapur Barrage. The Damodar River flowing through Dhanbad, Durgapur and Asansol have enriched the industrial sector of the region, not only that, but the country and the state have benefited from the subsidence of the Damodar basin over this large area, as such subsidence is rich in coal deposits, which enrich the country by coal mining. Moreover, the Damodar valley’s coal has been safely preserved on the ground due to some geological faults, especially in the Damodar River, where even earthquakes do not cause any damage to this precious coal deposit. Damodar river valley can also be called the breath of life in Jharkhand and the western part of Bengal. The historical city of Burdwan has been built on the banks of this river named after Mahavir, whose history is thousands of years old, and there are countless other stories such as the story of Sher Afghan-Meherunnessa (later Nur Jahan) all over Burdwan. Damodar river itself is empty today, tired of moving but continues to mine minerals even today, agriculture and farmers, society and towns are enriched by its sediments. In the mid-stretch, the river is much known for its industrial belt. Several heavy industries have been established for easy availability of raw materials along the course of Damodar. Series of heavy industries cause gradual degradation of the environment. To avoid more environmental deterioration, the state government has already taken up an afforestation programme in and around the large cities like Durgapur, Asansol etc. by the plantation of indigenous species befitting the local climate and soil substrates.

References 1. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 2. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 3. Chattopadhyay B, Datta S, Chatterjee A, Mukhopadhyay SK (2001) The environmental impact of waste chromium of tannery agglomerates in the east Calcutta wetland ecosystem. J Soc Leather Tech Chem 84:94–100

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4. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi 110032, p 94 5. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 6. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 7. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 8. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 9. Das GK, Datta S, Sanyal SK (2004) Need for Geomorphic mapping in terms of physicochemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 10. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 11. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9 12. Das GK (2011) Impact of salinity and nutrients on the changing mangrove floristic—a case study from the river flood plains of Sunderbans, India (119–129). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 13. Das GK (2011) Studies on the potentiality of medicinal applications of some mangroves of Sunderbans (68–73). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 14. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 15. Das GK (2014) Environmental scenario of Sunderbans: planning and management (1–24). In: Anthropecology and applied biodiversity. OmniScriptum GmbH & Co. KG, Saarbrucken, Germany, p 408 16. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN 978-3-319-11342-5 17. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN 978-3-319-44190-0 18. Das GK (2019) Medicinal plants around wetlands in Sunderbans. Frontier 1–3 19. Das GK (2020) Forest covers of West Bengal: a district wise review. Reason Tech J XIX:26–63. https://doi.org/10.21843/reas/2020/26-63/209272 20. Das GK (2020) Required optimum sample size determination of forest stands in West Bengal. E-J Appl For Ecol 8(2):1–6 21. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1 22. Das GK (2021) Forest integrity monitoring of Joypur and Beliatore forests in Bankura district, West Bengal. Indian Sci Cruiser 35(3):53–63. https://doi.org/10.24906/isc/2021/v35/i3/209193 23. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 24. Das GK (2022) Mahua tree and its products. Indian Sci Cruiser 36(4):11–12 25. Das GK (2022) Interference in the Elephant corridor: its effect and mitigation. Indian Sci Cruiser 36(4):13 26. Das GK (2022) Eucalyptus plantation in badlands. Indian Sci Cruiser 36(2):8–9 27. Das GK (2022) Environmental feasibility test for eucalyptus plantation applying statistical methods. Indian Sci Cruiser 36(2):52–53

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28. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 29. Jayaraman K (1999) A statistical manual for forestry research. Food and Agricultural Organization of the United Nations, Regional office for Asia and Pacific, Bangkok, p 231

Chapter 6

Changing Water Quality of Jalangi River

Abstract The river waters of Jalangi got polluted at its downstream stretch at Krishnanagar due to municipal waste discharge as well as mixing of industrial effluent. Jalangi river water has now been upgraded to usable condition for outdoor bathing after drastic sewage treatment by chlorination for disinfection of faecal coliform bacteria as well as using screen and sedimentation tank for the precipitation of different solids remained in the domestic sewage at the outlets of eight drains of Krishnanagar municipality. The water quality rating applying the values of water quality index shows 60% good and 40% fair conditions of surface water of Jalangi River for the months from January to May 2020 which was almost poor during 2013–14 and 2014–15 respectively. Application of modified standard values of individual parameters for the computation of WQI results in the appropriate WQI values reflecting the proper concentrations of physicochemical parameters of river waters of Jalangi. Keywords Water quality index · Water quality rating · Physicochemical parameters · Jalangi River · Churni · Anjana · Mathabhanga

6.1 Jalangi River Systems Jalangi originates from the Padma River in Murshidabad district and so, Jalangi is a distributary of Padma River and meets Bhagirathi in Nadia district i.e., Jalangi is a tributary of Bhagirathi River. The river is about 233 km in length without any headwater discharge at present from the river Padma. Moreover, for geographical reasons no tidal water enters river Jalangi at its confluence with river Bhagirathi as the riverbed of Jalangi is comparatively higher than that of Bhagirathi River. In such a perennial river, at its downstream stretch, Krishnanagar municipality and The Kishan Cooperative Milk Producer Union Ltd discharge domestic sewage as well as industrial effluents in the river waters of Jalangi. Apart from municipal wastes and industrial wastewater disposal, the local farmers are habituated to the

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_6

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6 Changing Water Quality of Jalangi River

processing of jutes by rotting raw jutes in the river water of Jalangi (Fig. 6.1). In this situation, chemical and microbial parameters like BOD (Biochemical oxygen demand) and most probable numbers of faecal coliform bacteria should not be the only criteria of water quality index (WQI) for prescribing the river water fitness for outdoor bathing as the aquatic environment of Jalangi River is a complex one for the mixture of domestic sewage, industrial effluents, and decomposed organic matters released from the rotting jutes [16, 17]. There must be other standardized physicochemical parameters which are relevant and significant to this degraded environment for the classification of the river environment for human usage. For this reason, the calculation of water quality index, standard values of such relevant and important parameters should be reconsidered for this particular environment at the downstream of Jalangi River. The examination of such relevant physicochemical parameters as well as reconsideration of standard values for the calculation of water quality index of Jalangi River, downstream of Krishnanagar in Nadia district would be helpful for the assessment of aquatic environmental parameters and water quality rating.

Fig. 6.1 Seasonal jute processing activities by the locals in Jalangi River at the outskirt of Krishnanagar municipal areas

6.3 Clay Dolls of Krishnanagar

93

6.2 River Environments Jalangi starts its course from Hasanpur of Murshidabad district as a distributary of Padma River where the river is not traceable at present, and it ends its journey at Swarupganj near Mayapur of Nadia district as a tributary of Bhagirathi River. The source of the Jalangi River at present is covered by only white sand, which makes it hard to identify the existence of the Padma and Jalangi rivers. Jalangi River in Karimpur area has knee-deep water during the post-monsoon period. However, local people can be seen taking a dip in the Jalangi River near Tehatta in the lower course. Apart from Krishnanagar downstream, all along the course of the Jalangi River is a long and gloomy scene of waterlessness. All the garbage from the villages and towns around the river gets mixed in the water of this river. No trees can be seen on the banks of the river. But there are a lot of floating plastic packets which become shiny when the sun shines on the river water. Already Jalangi River course is narrow, there is no flow current, the riverbed is loaded with huge quantities of silt and mud for sedimentation. Even after all this, the daily load of domestic sewage is released in the water of Jalangi River. But once the Jalangi used to flow with the rhythm of the waves with the water brought from the Padma River. In the past, some of the water hyacinths, jute sticks, or straws floated in the water and were lost in the estuary where the Jalangi meets the waters of the Bhagirathi River. But presently, the river has no current for most of the year, it swells and floods with monsoon water and water from the Padma River. Sometimes, floods occur along with the erosion of the riverbank. Planned or unplanned development along the banks of the Jalangi River causes such narrowing or reduced water capacity of the riverbed. However, the real reason is the population explosion. Another reason seems to be the urban migration of people [11]. For this reason, the once vibrant Jalangi is endangered today. In spite of all this, Jalangi River is connected in various ways with the life and livelihood of the people of Nadia district including Krishnanagar.

6.3 Clay Dolls of Krishnanagar Jalangi River water is useful for people and society. Riverside residents bathe in river water, wash clothes, or wash dishes. Fishermen catch fish in river water, farmers farm through river water irrigation, and even after jute cultivation, raw jute is decomposed in river water for jute processing. Not only the river water, but also the soil of the riverbanks and floodplains are of great help to the people living in the Jalangi River basin. Apart from farming, the soil of Jalangi River is used to make clay dolls which are known all over the world as Krishnanagar clay dolls. Clay dolls are very well made due to the special proportion of silt, sand and clay in this river soil. Potters in the Ghurni area within Krishnanagar city produce the most clay dolls. The clay dolls of Krishnanagar are so beautiful that they have been exhibited many times in London, Paris, and Boston.

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For making clay dolls, soil is first collected from the riverbanks or floodplains of Jalangi River and then the soil is specially prepared to make clay dolls. From that clay the skilled potter makes clay dolls with his construction skills. After making clay dolls with the soil, they are dried in the sun and painted. About 400 families are involved in making these clay dolls in Krishnanagar, out of which about 200 families live in the Ghurni area within the city. Most of these potters are called Pal or Paul. Pal or Paul is their family name. Maharaja Krishnachandra brought these potters from Natore (presently in Bangladesh) to Nadia district about 300 years ago to make clay idols of Gods and Goddesses. These potters from distant lands stayed in Krishnanagar in favour of the culture minded and benevolent Maharaja Krishnachandra. Now these potters are permanent residents of Krishnanagar. Clay dolls from Krishnanagar are now regularly exported to America and Europe.

6.4 River Characteristics The water quality index is computed for the river stretch at Krishnanagar downstream along Jalangi River in Nadia district of West Bengal that reveals the environmental degradation of river waters. The downstream of the river at Krishnanagar, however, has a lot of water, even flowing for months after monsoon time. Jalangi river water is polluted in Krishnanagar due to mixing municipal sewage. Even though the water of Jalangi River downstream at Krishnanagar was unfit for use some time ago, it has at least been suitable for outdoor bathing since May 2020. Due to the drastic initiative of the River Rejuvenation Committee as well as Krishnanagar municipality, the water of Jalangi is now suitable for outdoor bathing by rigorous water treatment on the wastewaters which is discharged in the river on a regular basis. The Water Quality Index revealed that the water quality of Jalangi is rather better than that of Churni River [18]. Jalangi River flows in the abandoned channel of Bhairab River at recent times, which (Bhairab River) is relatively older in the geographical areas of Nadia and Murshidabad districts because the Bhairab River became an abandoned channel long ago. Here the rivers used to flow along the southeast direction. But some forces like local subsidence pull the Mathabhanga, Churni and the Jalangi rivers towards the southwest direction, though there is no evidence of this force in Nadia and Murshidabad districts for almost the last three centuries. So, these rivers of Nadia district are young by origin. But no one knows how old they are, no one tried to find out. However, after the seventeenth century, these rivers became stable as geologists have proved it with evidence. Apart from Jalangi River in Nadia district, Churni River originates from Mathabhanga River which is younger than Jalangi River in age.

6.5 Physicochemical Parameters

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6.5 Physicochemical Parameters In surface waters of the Jalangi River, changes in turbidity, temperature, water colour including several other surficial properties may be considered as physical pollution [1, 2]. Oxygen depletion or eutrophication results can cause either organic or inorganic nutrient pollution [12–14, 29]. Changes of toxicity, acidity, alkalinity, or salinity alternations are directly related to chemical pollution which are revealed by the determination of pH, conductivity, DO, BOD, COD, TDS, TSS, TFS, TA, TH, and most probable number (MPN) of microbial organisms like faecal coliform in the river waters contaminated with the liquid effluents from the industrial plants along with domestic sewage released from the municipality and urban areas is considered as organic microbial pollution [15, 29–31]. Jalangi River, including other rivers of West Bengal is generally alkaline and has an influence on climate change mitigation by absorbing atmospheric carbon dioxide. For the analysis of BOD, two factors like temperature and time are very important to obtain accurate and reproducible results [24]. Like BOD, the occurrences of microbial populations are influenced by the availability of dissolved oxygen, temperature, pH, and ultimately the composition of wastes and sewage released in the river water [4]. COD analysis is concerned with rigorous chemical oxidation and for this reason, COD values show no relationship with that of BOD [27]. For wastewater treatment, chemical parameters of the river water like pH, conductivity, DO, BOD, COD, TDS, TSS, TFS, TA, TH, TKN etc. are to be standardized to the permissible limit for domestic or agricultural usage [22]. River water has a greater amount of dissolved solids as the part of direct run-off enters the river system soon after precipitation in the form of rain. Some dissolved substances in the form of total dissolved solids are present in the natural uncontaminated river waters [26]. River water is classified based on total dissolved solids as very soft (0–70 mg/l), soft (70–140 mg/l), slightly hard (140–210 mg/l), moderately hard (210–320 mg/l), hard (320–530 mg/l), and very hard (> 530 mg/l). TDS, TSS, and TFS values are rather higher for the river water of Jalangi in the upstream than that of the downstream stretch except a few exceptional cases [26]. Uses and utilization of river waters are generally determined by some selected physicochemical parameters like pH, conductivity, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), total fixed solids (TFS), total alkalinity (TA), total hardness (TH), calcium, magnesium, faecal coliform etc. [28]. Water quality index is computed averaging the data of pH, conductivity, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), total fixed solids (TFS), total alkalinity (TA), and total hardness (TH) based on the report of West Bengal Pollution Control Board in 2013–14 and 2014–15 respectively [2, 21].

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6.5.1 Turbidity Determining the cloudiness of river water is called turbidity. Description of suspended particles that scatter light or create obstacles in the path of light propagation is scientifically known as turbidity. Such suspended particles may be dissolved solid matter, phytoplankton, sediments or organic matter retained in the river water that block the light penetration or scatter in the river water in the aquatic environment [6, 7]. The permissible limit of turbidity is < 1.0 NTU as prescribed by WHO. The occurrence of turbidity is directly related to farming land and is negatively related to urban development depending particularly on the land use pattern around Jalangi River [23]. Viewing the fact, the turbidity level in the water of Jalangi River at Krishnanagar City should be in the process of gradual reduction due to the rapid urbanization of the town is in progress. The turbidity in the surface water of Jalangi River at Krishnanagar varies from 3.64 to 18.2 NTU from the month of January to May 2020 [3]. Turbidity is observed to be connected with the land use pattern and characteristics, properties of soil and different features of climate. Soil resistance and kinetic energy of raindrops during precipitation are directly interconnected with soil erosion of a particular topography that leads to the changes of turbidity of water in a fluvial system. For this reason, rainfall has more impact rather than drought for the cloudiness of river water i.e., turbidity. Turbidity is positively correlated with the total suspended solids [10]. So, the turbidity level becomes higher when runoff after the heavy rainfall drains into the river water that increases the total suspended solids by mixing of parasites, microorganisms, bacteria, viruses, and that may cause several diseases.

6.5.2 Ammonium Compounds Agricultural runoff causes the abundance of ammonium compounds in the freshwater ecosystems of the fluvial environment particularly when the fertilizers containing ammonium sulfate, ammonium nitrate etc. drain into the river [8, 9]. The river waterborne ammonium is measured as total ammonium. The mixing of several agents in river waters like industrial effluents, municipal wastewater, agricultural runoff containing fertilizers and land use patterns for rapid urbanization have the direct impact in controlling ammonium dynamics in the water bodies [19, 25]. Statistically, the ammonium concentration is positively correlated to the cycling of nutrient content in the river systems. The level of ammonium generally increases in the river water in the monsoon period. Higher concentration of ammonium is harmful for the freshwater ecosystem because the high content of ammonium caters to the heavy growth and abundant occurrence of algal populations that consume dissolved oxygen resulting in higher values of BOD in the fluvial system. The presence of ammonium in the river water triggers the nitrification process that accelerates to continue nitrogen cycle. Cyanobacteria may be in abundance in the river water only because of the presence

6.6 Water Quality Index

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of huge amounts of ammonium mixed in the river water from the different sources. The content of Ammonium-N in the river water of Jalangi near Krishnanagar City varies from 0.10 to 0.14 mg/l for the period from January to May 2020 whereas Nitrate–N ranges from 0.40 to 0.61 mg/l [3].

6.6 Water Quality Index For computation of water quality index considering the present situation of Jalangi River at its downstream, the standard values of individual parameters for calculation of WQI (water quality index) should be 1000 mg/l for TDS, TSS, and TFS of the river water samples because the values of TDS, TSS, TFS, and turbidity are interrelated where discharge of both industrial effluent and domestic sewage occurred on regular basis. Individual standard values for dissolved oxygen (DO) should be 5 mg/l which is its upper limit as standard value where pH remains constant at 7.5 though the river is alkaline throughout all seasons round the year. Standard values of BOD and COD should be 5 mg/l and 50 mg/l respectively because the industrial effluents are released without treatment (Table 6.1). Moreover, Jalangi is a river without headwater discharge from Padma River or tidal flow from the Bhagirathi River although it is a perennial river. Apart from physico-chemical parameters like pH, DO, BOD, COD, TDS, TFS, TA, TH, presence of microbial organisms in river water like faecal coliform bacteria may determine the water quality of Jalangi River [3, 20]. If these important parameters in majority are taken into account for the computation of water quality index, the obtained results may be better than applying the conventional standards of the chemical parameters fixed by the Central Pollution Control Board. It is observed that more physicochemical and microbiological parameters are incorporated in the calculation of water quality index, the computed values show more precise results. And when standard values of individual parameters are modified, the obtained results show better water quality index values where similarities are found with the physicochemical parameters as recorded by the River Rejuvenation Committee [20]. The faecal coliform bacteria occur in the river surface waters making a large colony form off and on. The number of faecal coliform bacteria varies from thousands to millions in such a colony. If the water sample is collected from such a surface area of river water containing a huge bacterial colony, it affects bacterial counts and Table 6.1 Modified standard values of individual parameters for the computation of water quality index (WQI) Modified standard values of individual parameters for calculation of WQI pH

Conductivity

DO

BOD

COD

TDS, TSS, TFS

TA, TH

7.5

250 µs/cm

5 mg/l

5 mg/l

50 mg/l

1000 mg/l

200 mg/l

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Table 6.2 Water Quality Index (WQI) of water samples of Jalangi River at Krishnanagar Year

WQI of Jalangi River Downstream, Krishnanagar Pre-monsoon

Monsoon

Min

Max

Min

Max

Post-monsoon Min

Max

2013–14

38.35 (Good)

58.35 (Fair)

31.33 (Good)

39.37 (Good)

33.40 (Good)

57.21 (Fair)

2014–15

40.77 (Good)

58.07 (Fair)

28.92 (Good)

48.07 (Fair)

35.81 (Good)

67.31 (Poor)

Rating of water quality within parenthesis

generally the obtained data will not reflect the average number. Sometimes such abnormal numbers of faecal coliform bacteria are observed in the report of River Rejuvenation Committee [3, 20]. The computation of water quality index considering faecal coliform bacteria as one of the parameters shows varied results for the surface water quality rating for Jalangi River. For this reason, faecal coliform bacteria are excluded in computation of WQI. From the computed water quality index applying conventional standard values of individual parameters, water quality rating indicates that Jalangi river water contains about 58% good, 34% fair, and 8% poor water conditions as per standard water quality rating chart during three principal seasons of South Bengal i.e., pre-monsoon, monsoon, and post-monsoon (Table 6.2). Water quality index reveals that water quality of Jalangi River downstream of Krishnagar is in good conditions for most part of the year where poor water condition is only observed during the month of January in post-monsoon season in 2014–15 due to increasing values of total dissolved solids. Except for the post-monsoon period, the water quality of Jalangi River in its downstream stretch is either fair or good during 2013–14 and 2014–15. Despite such river water conditions, Jalangi River is not befitted for outdoor bathing as the most probable number of faecal coliform bacteria is very high and beyond the permissible limit [20]. The most probable number of faecal coliform bacteria ranges from 1700 to 300,000 in 100 ml river water samples during 2013–14 and from 4000 to 110,000 per 100 ml river water in 2014–15. Such a high number of faecal coliform bacteria is nothing but the consequence of the discharge of municipal wastewater of Krishnanagar into Jalangi River through the drainage systems of the municipality without treatment. After treatment of wastewater, the numbers of faecal coliform bacteria lessen to 1700, 3000, and 2000 MPN/100 ml respectively in the months of February, March, and May 2020. For this reason, the most probable number of faecal coliform bacteria is not included in the calculation of water quality index not only for these months, but for the remaining two months of January and May 2020. The water quality index ranges from 33.5 to 51.85 for these 5 months from January to May 2020 that indicates good to fair conditions of the surface water as per the chart of water quality rating (Table 6.3). The surface water quality index reveals that the Jalangi river water downstream of Krishnanagar is almost usable for outdoor bathing. The water quality index shows 60% good and 40% fair conditions of surface water for the months from January to May 2020 (Table 6.3).

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Table 6.3 Water quality index of river waters of Jalangi at downstream of Krishnanagar for the period from January to May 2020 Jalangi River Downstream of Krishnanagar Months (2020)

January

February

March

April

May

WQI

45.09 (Good)

44.62 (Good)

51.85 (Fair)

47.35 (Fair)

33.5 (Good)

Rating of water quality within parenthesis

6.6.1 Remarks Water quality rating indicates that Jalangi river water contains about 58% good water, 34% fair water, and 8% poor water conditions in average as per standard water quality rating chart based on the values of the computed water quality index applying conventional standard values of individual parameters in 2013–14 and 2014–15 respectively. In 2020, treatment of wastewater before draining into the river water changes the values of the surface water quality index that reveals the Jalangi river water downstream of Krishnanagar is almost usable for outdoor bathing.

6.7 Summary Jalangi River is the lifeline of Krishnanagar city. But jute rotting is going on in the river Jalangi which flows along Krishnanagar city which makes the water of the river unfit for use. The level of water pollution has been reduced to some extent by treating sewage effluents from municipal areas and releasing them into rivers. From the point of view of the concentration of biochemical oxygen demand, the water pollution level of Jalangi River is currently considered in the category of Priority IV by the Central Pollution Control Board [5]. The biochemical oxygen demand level of Jalangi river water has decreased from 8.3 to 6.2 mg/l in 2022 compared to 2018 as per the report of the CPCB. At the same time, the river stretch of pollution has decreased from Laldighi to Krishnanagar in 2018 to along Krishnanagar city in 2022.

References 1. Anonymous (1996) Standards for liquid effluents, gaseous emissions, automobile exhaust, noise and ambient air quality. Central Pollution Control Board (CPCB), Ministry of Environment and Forests, Government of India, Pollution Control Law Series, PCL/4/1995-96 2. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal, pp 1–201

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3. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 4. Bartha C, Jipa M, Caramitu AR, Voina A, Tókos A, Circiumaru G, Micu DD and Lingvay I (2022) Behavior of microorganisms from wastewater treatments in extremely low-frequency electric field. Biointerface Res Appl Chem 12(4):5071–5080. https://doi.org/10.33263/BRI AC124.50715080 5. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi 110032, p 94 6. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 7. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 8. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 9. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 10. Das GK, Datta S, Sanyal SK (2004) Need for geomorphic mapping in terms of physico-chemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 11. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 12. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9 13. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, pp 1– 211. ISBN 978-3-319-11342-5 14. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, pp 1–151. ISBN 978-3-319-44190-0 15. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, pp 1–231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1 16. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 17. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 18. Das GK (2023) Water quality index of Churni and Jalangi rivers, West Bengal, India. Int Res J Environ Sci 12(1):14–18 19. Du Y, Ma T, Deng Y, Shen S, Lu Z (2017) Sources and fate of high levels of ammonium in surface water and shallow groundwater of the Jianghan Plain, Central China. Environ Sci: Process Impacts 19:161–172 20. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 21. Galal Uddin Md, Nash S, Agnieszka I, Olbert A (2021) Review of water quality index models and their use for assessing surface water quality. Ecol Indicators 122:107218. https://doi.org/ 10.1016/j.ecolind.2020.107218 22. Langone M, Sabiab G, Pettab L, Zanettic L, Leonic P, Bassoc D (2021) Evaluation of the aerobic biodegradability of process water produced by hydrothermal carbonization and inhibition effects on the heterotrophic biomass of an activated sludge system. J Environ Manage 299. https://doi.org/10.1016/j.jenvman.2021.113561 23. McCarthy MJ, Muller-Karger FE, Otis DB, Mendez-Lazaro P (2018) Impacts of 40 years of land cover change on water quality in Tampa Bay, Florida. Cogent Geosci 4(1). https://doi.org/ 10.1080/23312041.2017.1422956

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24. Muralikrishna IV, Manickam V (2017) Analytical methods for monitoring environmental pollution. Environ Manage. https://doi.org/10.1016/B978-0-12-811989-1.00018-X,495-570 25. Shi K, Zhang Y, Zhu G, Liu X, Zhou Y, Xu H, Qin B, Liu G, Li Y (2015) Long-term remote monitoring of total suspended matter Concentration in Lake Taihu using 250 m MODIS-Aqua data. Remote Sens Environ 164:43–56. https://doi.org/10.1016/j.rse.2015.02.029 26. Subramanian V (2011) A textbook of environmental chemistry. I.K. International Publishing House Ltd., New Delhi, pp 1–482. ISBN 978-93-81141-19-9 27. Tyagi VK, Lo SL (2016) Energy and resource recovery from sludge: full-scale experiences, environmental materials and waste, resource recovery and pollution prevention, pp 221–244. https://doi.org/10.1016/B978-0-12-803837-6.00010-X 28. Weide T, Brügging E, Wetter C (2019) Anaerobic and aerobic degradation of wastewater from hydrothermal carbonization (HTC) in a continuous, three-stage and semi-industrial system. J Environ Chem Eng 7(1). https://doi.org/10.1016/j.jece.2019.102912 29. WHO (2004) Health risks from drinking demineralized water. WHO, USA 30. WHO/UNICEF (2005) Water for life: making it happen. ISBN 92-4-156293-5 31. WRN (2016) Water Research Net, pH in the Environment. Available from http://www.waterresearch.net/index.php/ph-in-theenvironment. Accessed 3 Jun 2016

Chapter 7

Environmental Morphodynamics of Rupnarayan River

Abstract The confluence of the Rupnarayan River is located in between the other two river estuaries at a distance of only a few kilometers. The other two river estuaries Damodar and Haldi lie to the north and south respectively of the Rupnarayan which outfall into the Hooghly River. The water of these river estuaries enters and mixes with the water of Rupnarayan River at high tide. Effluents released from Kolaghat thermal power plant and wastewater released from Haldia industrial area mixes with the tidal water of Rupnarayan River which pollutes the river water. Sewage discharges from Haldia, Tamluk and Kolaghat municipalities mixed with the waters of Rupnarayan and became unusable most part of the year. Apart from such pollution, the water of Rupnarayan is now slightly saline for increasing water salinity in the lower reaches of Hooghly River due to sea level rise. Consequent upon the existence of low salinity in estuarine water, abundant occurrence of giant prawn broods in the confluence has changed the socioeconomic pattern in the localities of three districts surrounding the Rupnarayan River. Keywords Bank erosion · Riverbank management · River network · Rupnarayan · Water quality index · River commons

7.1 Rupnarayan River Course River Rupnarayan, about 80 km in length, is entirely a tidal freshwater river lacking a forest patch along its course [21]. The river has its origin from the lower tidal reach below the confluence of Dwarakeswar and Shilabati near Bandar at Ghatal of Paschim Medinipur district. At its mid-stretch, Rupnarayan receives huge quantities of water through the discharge by the main flow of Damodar in the form of Mundeswari channel after its bifurcation into two separate channels near Baguhana. Not only the main flow of Damodar i.e., Mundeswari, but Palaspai creek or Old Kansai, a branch of Kangsabati River discharges into Rupnarayan at Gopiganj and increases water load of the flow before outfall of Rupnarayan into Hooghly River at Geonkhali of Purba Medinipur district (Fig. 7.1). The river is not so wide in its upstream particularly at

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_7

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its site of origin i.e., in and around the place of union of Dwarakeswar and Shilabati rivers. Rupnarayan has gradually been widening after receiving discharges from Mundeswari and Old Kansai rivers that form a big river along its downstream stretch.

Fig. 7.1 Confluence of Rupnarayan and Hooghly rivers at Geonkhali of Purba Medinipur district (top) and Gadiara of Howrah district (below)

7.2 River Morphodynamics

105

7.2 River Morphodynamics The Union of Dwarakeswar and Shilabati forms the Rupnarayan River at Bandar near Ghatal town (Fig. 7.2). Rupnarayan is considered as the main river of both Purba Medinipur and Paschim Medinipur districts whereas Dwarakeswar might be considered as the biggest river of Bankura district. Dwarakeswar starts its journey from Purulia district and divides into two halves. This is an important river for Bankura town where river Gandheswari, rising from Saltora meets Dwarakeswar River. Before entering Hooghly district, Dwarakeswar receives water from its tributaries like Adusha, Borai etc. and ultimately unites with Shilabati River near Ghatal to form Rupnarayan River. Like Dwarakeswar, Shilabati River rises in Purulia and flows southeastward before its union with Dwarakeswar River [22]. Before the confluence of Dwarakeswar with Shilabati, the latter received water from a number of its tributaries like Jaypanda, Kulbai, Tamal and Parang. In a stream like Rupnarayan, discharges of sediment and water and their overall balance indicates a stable channel [13, 19]. When these criteria i.e., overall balance of sediment and water discharge has not been fulfilled, local scour may be created at points and accretion at another. Aggradation or degradation of the river morphodynamics reflect very fast for any gross imbalance between water and sediment

Fig. 7.2 Origin of Rupnarayan River (right) from the union of Dwarakeswar (mid-stream) and Shilabati (left) rivers at Bandar near Ghatal of Paschim Medinipur district

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7 Environmental Morphodynamics of Rupnarayan River

discharge. In a meandering tidal river system, high velocity at a particular area causes erosion at outside riverbank as well as accretion in the inside riverbank simultaneously. Naturally, artificial riverbank protection is necessary not only for a tidal meandering river but also for a graded stream [18]. The applied movements about a point of contact between the sediment grains are sometimes greater than the resting movement which leads to the initiation of erosion at the flow boundary. The forces working on the individual sediment grain on the point of movement are the fluctuating hydrodynamic forces and the steady attractions of gravity. The fluctuating hydrodynamic forces include viscous forces, pressure gradient, forces due to seepage into or out of bed and impact due to particles in motions [1, 26]. The reasons behind the fluctuating hydrodynamic forces are the origin, motion, and decay of eddy with flow and time. As a consequence, movement of the sediments acting in separate places on the bed surface seems to be an intermittent process at low flow rates [26]. Critical velocity or critical shear stress exists there below which significant sediment motion continues [4]. Sediment grains start rolling and sliding only when the instantaneous applied forces exceed resistance that causes occurrences of bed load sediment transport. When the instantaneous lift force is greater than the submerged grain weight, sediment particles may be pulled up from the riverbed and mixed in the suspension within the flow with the assistance of turbulent eddies [26]. In such a river system, scours of the riverbeds and riverbanks are collectively termed as river scour where riverbank scour needs special attention for protective measures. Causes of the damaged riverbanks of Rupnarayan are paid special attention. Riverbanks damaged due to scour or shear failure are identified first with thorough observations and field surveys and then remedial measures are to be applied for each separate distinct cause for the damage of riverbanks [27]. If the river scour causes damage to riverbanks, then revetments, vegetation cover or groins like treatments are to be taken which are necessary to maintain flow with scouring velocity safely away from bank materials. Apart from river scour, when sliding is concerned for riverbank damage, embankment slope is to be reduced or an intermediate berm is to be installed that may enhance the stability of riverbank or compactness of soil for the improvement of shear strength including the fair flow of drainage that reduce seepage pressure [23].

7.3 Riverbank Erosion Rupnarayan is an erosion-prone river in the downstream and faced erosion for years at its right bank near Geonkhali as per the records of 1955, 1965, 1968, 1972, and 1985 by the Calcutta Port Trust [1]. The Calcutta Port Trust selected the Rupnarayan cross section for their study at Natshal, about 2 km upstream of Geonkhali. Geonkhali of Purba Medinipur district stands at the confluence of Rupnarayan and Hooghly rivers surrounded by Gadiara of Howrah district in the north side, and Noorpur of South 24 Parganas from the east side (Fig. 7.3). At Natshal, in the riverbed of Rupnarayan, a submerged tidal shoal continues rising and dividing the entire flow into two distinct

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107

separate streams for about 70 years that keep the left bank remain more or less unchanged since fifties of the last century to till date whereas the right bank tends to move outside resulting development of a bend of the river course. Apart from the Calcutta Port Trust, River Research Institute (RRI) of West Bengal had made several hydrographic surveys in the east and west gully in 1977, 1979, and 1985 respectively. Both observational data of Calcutta Port Trust and River Research Institute have been utilized to interpret tidal morphodynamics of Rupnarayan River [1]. As per the hydrographic observations of the River Research Institute, the rough bed condition is predominant during the ebb tide [1, 4]. The average laminar sublayer thickness higher than the roughness height controls the conditions of no scour formation during the ebb period at Natshal (Fig. 7.4). But the distribution of radial velocity with the angle of deviation of the main flow from the bank line tends to the riverbank of Rupnarayan near Geonkhali, a vulnerable zone of erosion. River Research Institute observed that the radial velocity is different in direction from surface to bottom in downstream stretches of Rupnarayan River [4, 27]. The distribution of radial velocity is positive from surface to mid-depth that leads to the water mass flow towards the bank whereas radial velocity is negative from mid-depth to bottom which attracts water mass away from the bank. Maximum values of radial velocity are near surface

Fig. 7.3 Location map of Rupnarayan-Hooghly River confluence surrounded by Purba Medinipur, Howrah and South 24 Parganas districts

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7 Environmental Morphodynamics of Rupnarayan River

Fig. 7.4 Graphical representation of laminar sublayer thickness against roughness height of Rupnarayan River at Natshal of Purba Medinipur district

and near bottom respectively whereas the value shows zero at mid-depth of the water mass of the river [1, 4, 27].

7.4 Riverbank Management River scour disturbs the channel stability of the entire Rupnarayan river system. Along its downstream stretch in Purba Medinipur district, particularly in the left bank, a series of submerged tidal bars are formed that bifurcate the tidal flow pattern of the river as the river is tidal along its entire course. The sediments accumulated in the riverbed require deepening and widening the channel by dredging out of bed materials and the same should be dumped on the riverside of erosion. Only such dredging effort on the riverbed may wash away the accreted bed materials and thus, widen, deepen, and extend the river course and consequently will reduce the intensity of scour by increasing laminar sub-layer for maintaining bed stability. The effect of spiral motion cannot be abolished completely for a tidal river situation but to be checked by applying remedial measures which will accelerate the transportation of accumulated bed materials from the depositional sites to the areas of erosion. Installation of porcupines in rows, a common protective measure for riverbank management may help silt accumulation in the vulnerable zone by the sediment baffling effect. To achieve such siltation effect in the concave riverside areas, rows of porcupines should be set up keeping their angle of inclination must be higher than the angle of deflection of the river flow. However, the top of the porcupines at mid-depth of the high-water line of the river may help rather better result in arresting sediment particles in the vulnerable zone. Below the low water line, launching the apron may help

7.5 River Water Characteristics

109

in protection of the bank where the length of launching apron should cover the anticipated scour depth if it is applied for the riverbank protection of Rupnarayan. Apart from the use of porcupines and launching aprons, block pitching up to low water lines in the concave bank is useful for the protection of riverbanks of Rupnarayan from erosion [18, 19].

7.5 River Water Characteristics Generally, total dissolved solid (TDS) is computed from electrical conductivity (EC) as it is a time-consuming method [25]. Total dissolved solids assume to be predominantly ionic species of low enough concentration to yield a linear total dissolved solid-electrical conductivity relationship that is expressed as TDS in mg/L = ke × EC in µS/cm where ke is the constant of proportionality. Total solid is calculated with the sum total of the total suspended solids and total dissolved solids in the process of water [16]. TDS ranges from 90 to 2748 mg/l at Geonkhali and from 66 to 1396 mg/l at Kolaghat whereas TSS ranges from 60 to 762 mg/l at Geonkhali and 2 to 474 mg/ l at Kolaghat. Electrical conductivity is much higher in Rupnarayan water for higher TDS values and ranges from 226 to 4250 µS/cm at Geonkhali and from 163 to 2220 µS/cm at Kolaghat [2]. Water quality indices of Rupnarayan of Kolaghat and Geonkhali have been determined using standard statistical formulas. The determined values of water quality indices show that the water quality of Rupnarayan River is very poor during premonsoon and post-monsoon periods (Table 7.1). Only during monsoon, the water quality of this river is good and suitable for outdoor bathing by local people [6– 8]. The water of this river is not suitable for drinking due to the presence of faecal coliform bacteria (2000–130,000 MPN/100 ml) in abundance. Faecal coliform bacteria are found in high numbers due to sewage discharge from Tamluk, Kolaghat, and Haldia municipalities mixing with Rupnarayan river water. Mixing of wastewater increases the level of BOD in river water of Rupnarayan and BOD ranges from 0.5 to 8.2 mg/l though this maximum value of BOD (8.2 mg/l) is occasional. According to the West Bengal Pollution Control Board, the river water is polluted along the stretch from Kolaghat to Benapur as BOD ranges from 3.1 to 5.8 mg/l along this stretch of Rupnarayan [3, 5]. As per standard values BOD concentration up to 3 mg/l or less is suitable for outdoor bathing. Water pH ranges from 5.97 to 8.38 indicating both acidic and alkaline characteristics of the river water. Fluctuation of pH in the water of Rupnarayan is due to the wastewater discharge by the Tamluk, Kolaghat, and Haldia municipalities and release of industrial effluents from the Haldia petrochemicals and Kolaghat thermal power plant. In the lower reaches and confluence of the Rupnarayan River, WQI is poor due to the high concentration of TDS. The reason for this excess TDS is the mixing of industrial effluents with Rupnarayan river water from Kolaghat thermal power plant and Haldia industrial areas along with the sewerage water of Tamluk, Kolaghat and Haldia municipalities. Besides, the Damodar River estuary at Garchumuk of Howrah

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Table 7.1 Water Quality Index (WQI) of samples collected at different locations of Rupnarayan River Sample Locations

Year

Kolaghat

Geonkhali

Pre-monsoon

Monsoon

Min

Max

Min

Max

Post-monsoon Min

Max

2013–14

88.28 (Poor)

161.73 (Poor)

40.41 (Good)

65.52 (Poor)

42.33 (Good)

59.21 (Fair)

2014–15

54.16 (Fair)

92.24 (Poor)

33.84 (Good)

98.78 (Poor)

29.11 (Good)

89.63 (Poor)

2013–14

110.39 (Poor)

242.59 (Poor)

44.26 (Good)

118.85 (Poor)

51.67 (Fair)

82.98 (Poor)

2014–15

60.22 (Fair)

289.99 (Poor)

52.48 (Fair)

204.07 (Poor)

44.72 (Good)

90.81 (Poor)

Rating of water quality within parenthesis

district is a short distance from the Rupnarayan river mouth, so the water mixed with sewage carried by the Damodar River enters the Rupnarayan River. Haldia Industrial Area and Municipality is located at the estuary of Haldi River which is a short distance from Rupnarayan river estuary at its meeting point with Hooghly River. Effluent discharged from Haldia industrial area and municipal sewage flows into the tidal stream and mixes with the water of Rupnarayan River that pollutes the water [9, 10]. Due to the higher concentrations of TDS, TSS, and EC the water of Rupnarayan River got polluted. There is a linear relationship between TDS and EC such that higher TDS values will increase EC concentration of the river water. From the computed water quality index, water quality rating indicates that Rupnarayan river water contains about 25% good water, 54% poor water, and 21% fair water as per standard water quality rating chart during three principal seasons of South Bengal i.e., pre-monsoon, monsoon, and post-monsoon (Table 7.1). Due to the existence of 54% poor surface water of the river, Rupnarayan river water is not suitable for outdoor bathing.

7.6 Changing Water Characteristics for Climate Change Slow but gradual saline water intrusion and mixing with the river water during high tide as a result of sea-level rise due to climate change continues changing of water quality that affect river ecosystem at the confluence of Rupnarayan and Hugli River where the evening sky of Geonkhali is blazed by the flame emerged from the Haldia Port and that is seen from the bank of Rupnarayan at Gadiara, a well-known tourist spot of Howrah district [11, 12]. Anybody could enjoy the overwhelming landscape, scenic beauty and triangle shaped water mass at the confluence of river Rupnarayan and Hugli surrounded by Geonkhali of Purba Medinipur, Gadiara of Howrah and Noorpur of South 24 Parganas. A visitor standing on the riverbank at Gadiara enjoyed every moment of enchantment from the top of the terrace of Rupnarayan. But just

7.6 Changing Water Characteristics for Climate Change

111

down to the riverbank at its edge where river water-ripples touch the sandy silt textured flood plain adjacent to the land surface, it tells the tale of truth and toil. Mostly dropout teen aged girls are involved in the netting operations for capturing giant freshwater prawn broods in the evening during ebb time that costs one rupee each or sometimes more. It is like a painting of watercolour medium framed with a theme of just existence and survival for these school dropout girls at the spot where the southern breeze hugs the people who pass in idleness at their leisure. And it matters in reality that a girl could earn nearly 200 INR a day by 6–8 h of continuous fishing gear operations by a drag net during ebb tides when water gently recedes. The occurrence of Galda chingri meen i.e., giant prawn (Macrobrachium rosenbergii) broods have been enhanced with the increasing salinity at the water of river Hugli and Rupnarayan. The location of the study area is the confluence of Hugli and Rupnarayan rivers, which is surrounded by Gadiara of Howrah District from northwest, Noorpur of South 24 Parganas district from the east and Geonkhali of Purba Medinipur district from southwest. This triangle-shaped geomorphic situation is also important for the abundant occurrence of prawn broods. The study of water samples reveals that the abundance of prawn broods is enhanced with the increasing salinity in the river waters [14, 15, 17]. The water of RupnarayanHooghly confluence at Gadiara, Noorpur and Geonkhali are generally non-saline during monsoon period. The intrusion of mixing-up low saline brackish waters beyond Diamond Harbour along the course of river Hooghly comes upstream and the waters from the Rupnarayan confluence enters along its upstream only during the period of pre-monsoon season. The waters at the confluence of river Rupnarayan and Hooghly, therefore, get salinised for mixing with saline water entering into the river from the Bay of Bengal due to sea-level rise as a result of the impact of climate change and cause the abundant occurrences of giant prawn broods in this region at pre-monsoon period. The indented bank of river Rupnarayan at Gadiara is the main spot for abundant occurrences of post larvae i.e., prawn broods of giant freshwater prawn (Galda chingri). The tiny post larvae of prawn drift in the river waters, as they are planktonic by nature. The giant freshwater prawn is scientifically known as Macrobrachium rosenbergii. The prawn broods occurred mostly in clear water at the pouch-like locales of the erosion site i.e., the inner convex bank of the river. Slight increase in parts per thousands of water salinity of the river waters play a major role in the occurrence of prawn broods in the river. It is interesting to observe that the drifting trend of post larvae of giant prawns is switched on with the increasing salinity of river water during pre-monsoon. Water samples were collected from different locations namely Gadiara and Shibpur of Howrah, Noorpur of South 24 Parganas and Geonkhali of Purba Medinipur district to estimate the water salinity during the pre-monsoon period. After analysis of those water samples the salinity is recorded as follows—at Noorpur around 1 ppt; Gadiara > 1 ppt; Shibpur < 1 ppt and the salinity at Geonkhali is about 0.7 ppt (ppt stands for parts per thousand). Prawn broods occur where salinity ranges between 0.25 and 1 ppt at Gadiara and Noorpur at the pocket like indented portion of the riverbank with compact silty and stable substratum [20]. So, the geomorphic situation is also an important factor in the giant

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7 Environmental Morphodynamics of Rupnarayan River

freshwater prawn brood occurrences [16, 17]. Other than the areas of erosion, the lower flood plain covered with tiny grass mat face tidal action is another site where giant prawn broods occur at the distal eastern part of Gadiara area. The collected materials after netting operations are preliminarily sorted out for the prawn seeds mainly for the broods of Macrobrachium rosenbergii and thereafter the rest of the materials are left aside on the riverbank or upon the river embankments. A large number of shellfish and finfish are also encountered in this process along with the prawn seeds. This, in turn, is bringing about a tremendous impact in the food web of the river ecosystem, as the collection of giant prawn seeds along with other encounter species is nearly a year-long phenomenon. Numerous finfish and shellfish are suffering a severe loss in population because of random exploitation during sorting out of giant prawn broods. This, in turn, adds to a tremendous threat to the balance of the total ecosystem in and around the confluence of Rupnarayan and Hugli River surrounded by the riversides of three districts.

7.7 Summary The river stretching from Kolaghat to Benapur of Rupnarayan is declared polluted to a large extent by the West Bengal Pollution Control Board due to the high values of BOD ranging from 3.1 to 5.8 mg/l [3, 5]. However, the water quality of the river from Kolaghat downstream to Geonkhali in the estuary is of poor quality as per obtained values of water quality index. Further, the river water is also not suitable for outdoor bathing as per the available number of faecal coliform bacteria found in the river water after laboratory analysis. Deterioration of Rupnarayan River water is due to mixing of effluents from Haldia industrial area and Kolaghat thermal power plant along with sewage discharge from Kolaghat, Haldia and Tamluk municipalities. Therefore, in river water, concentration of TDS, TSS, EC, and BOD are comparatively higher along with the existence of faecal coliform bacteria in numerous numbers in the river water of Rupnarayan [22, 24]. Besides, at present, brackish water from Hooghly River flows more upstream along the course of the river due to sea level rise and mixes with the water of Rupnarayan. As a result, the river water at the confluence of Rupnarayan turns into brackish water (about 0.5 to 1 ppt) that helps generate giant prawn broods in huge numbers [12]. The capture of such giant prawn broods has changed the socioeconomic status of the local people though Rupnarayan is famous for the capture of hilsa fish at Kolaghat for centuries.

References

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References 1. Anonymous (1989) Research schemes applied to river valley projects. C.B.I.P Project, Annual Review 2. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 3. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 4. Basu AN, Chakrabarty K, Bhandari PC (1973) Mathematical model for entire Rupnarayan River. River Behav Control VII:1–68 5. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi 110032, p 94 6. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 7. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 8. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 9. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 10. Das GK, Datta S, Sanyal SK (2004) Need for Geomorphic mapping in terms of physicochemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 11. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 12. Das GK (2005) Prawn seed collection at Gadiara—a threat to the balance of nature. IGA Review, Max Mueller Bhavan, Kolkata, pp 15–16 13. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9 14. Das GK (2011) Impact of salinity and nutrients on the changing mangrove floristic—a case study from the river flood plains of Sunderbans, India (119–129). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 15. Das GK (2011) Studies on the potentiality of medicinal applications of some mangroves of Sunderbans (68–73). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 16. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 17. Das GK (2014) Environmental scenario of Sunderbans: planning and management (1–24). In: Anthropecology and applied biodiversity. OmniScriptum GmbH & Co. KG, Saarbrucken, Germany, p 408 18. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland,p 211. ISBN 978-3-319-11342-5 19. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN 978-3-319-44190-0 20. Das GK (2019) Medicinal plants around wetlands in Sunderbans. Frontier 1–3 21. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1

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22. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 23. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 24. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 25. Ewing GN (1985) Instrumental method of chemical analysis. McGraw Hill Book Company, New York, p 624. ISBN 978-0070198517 26. McDowell DM, O’Connor BA (1977) Hydraulic behaviour of estuaries. Macmillan Publishers Limited, p 292. https://doi.org/10.1007/978-1-349-01118-6 27. Roy SC, Bhandari PC, Roy SK (1991) On some aspects of stability of tidal channel. C.B.I.P Project, Annual Review

Chapter 8

Water and Environments of Kangsabati River

Abstract The Kangsabati River, famous for the Kangsabati Reservoir in Mukutmanipur, flows across Purulia, Bankura, and Paschim Medinipur districts and joins the Keleghai River in Purba Medinipur district to form the Haldi River. For various reasons including transport and communications across the course of this river upstream the normal flow has practically been stopped. Due to damming on a temporary basis particularly in middle and downstream stretches the river is in dying condition particularly during the lean time. Although there are no significant cities other than Midnapore town, the Kangsabati water pollution is caused by mixing of waste materials in the river water from the non-point sources. The pollution level of this river is determined and categorized as priority IV because the value of BOD concentration shows 6.4 mg/l of the surface water samples of Kangsabati River near the Midnapore town. Keywords Water characteristics · Kangsabati · Keleghai · Kapaleswari · Changing river course · River commons · Water quality indices

8.1 Kangsabati River Course The Kangsabati or Kansai, about 465.23 km in length, is one of the major rivers of southwestern West Bengal (Fig. 8.1). This river is mentioned as Kapisha in Kalidasa’s Meghdootam and other Sanskrit literature. According to legend, when Krishna in the form of the river Damodar rushed to embrace Kangsabati, then Kangsabati rushed to meet her fiancé, the ocean. On the bank of such a mythological river Kangsabati, Midnapore town is located along the course of this river. The river Kangsabati originates from a hill about 600 m high in Jhalda region of Purulia district in the form of Jabarban Kansai Nala. A small stream called Saharjhora from the nearby Ajodhya Hills then joins the Kangsabati near Begun Kodar. Bandhu or Bandu River falls into Kangsabati near Teldihi village. The Kangsabati then moves east across the PuruliaChandil railway line and joins the Karmara Nama at a short distance. The river enters Bankura district after crossing Vedua village. Its confluence with the Kumari River,

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_8

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8 Water and Environments of Kangsabati River

Fig. 8.1 Kangsabati River course near Moyna in Purba Medinipur district

the main tributary of the Kangsabati, is at Mukutmanipur of Bankura. The famous Kangsabati dam and reservoir is built at the confluence of the Kangsabati and Kumari rivers in Mukutmanipur (Fig. 8.2). The Kangsabati Dam and Reservoir have been constructed on the confluence of the Kangsabati and Kumari rivers in the bordering areas of Bankura and Purulia districts of Khatra. These dams and reservoirs were constructed in 1956 to facilitate irrigation during the Second Five Year Plan. The area of the reservoir is 86 km2 . A picturesque tourist center has developed in Mukutmanipur around this reservoir. Leaving the dam, Kangsabati flows south-east past Raipur and enters Binpur area of Paschim Medinipur district. This river joins the Bhairab Banki River and then enters Paschim Medinipur district. Near Keshpur, the river splits into two branches. One branch flows over Daspur region named Palaspai Khal meets Rupnarayan River and the other branch flows south-east to join Kaliaghai or Keleghai River. Keleghai River joins the Kangsabati River to form Haldi River which is tidal along its entire course. All these fluvial and tidal rivers and rivulets consist of the Kangsabati River system. The water quality rating of Kangsabati River including river commons with the perspective of socioeconomic and ecological point of view is important for the study of riverine environment.

8.2 Kangsabati River System

117

Fig. 8.2 Kangsabati reservoir at Mukutmanipur in Bankura district

8.2 Kangsabati River System The river system of Kangsabati is formed with its tributaries like Saharjhora, Bandu or Bandhu, Kumari, and Bhairab Banki including other fluvial arteries like Keleghai, Kapaleshwari and Haldi rivers.

8.2.1 Saharjhora Saharjhora originates from Ajodhya Hills. A reservoir has been constructed on this river at Murguma mainly to facilitate irrigation. It then merges into the Kangsabati near Begun Kodar.

8.2.2 Bandu Bandu or Bandhu river descends from Ajodhya Hills near Sirkabad along with several other streams like Sarambisi, Burudi etc. After crossing 24 km, it outfalls into Kangsabati near Teldihi village.

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8 Water and Environments of Kangsabati River

8.2.3 Kumari The main tributary of Kangsabati is Kumari River. Its source of origin is Ajodhya Hills. Kumari joins several small streams while coming down the eastern slope of the hill. It flows south-east and crosses the Purulia-Chandil railway line touching Barabhum and Manbazar and then enters Bankura district. Along its course, four tributaries from the different sources of origin like Hanumata and Nangasai (right tributaries) and Jhor and Chaka (left tributaries) merge into the Kumari River. On the other hand, the Totka River in Jharkhand crosses Bandwan and joins the Kumari River near Majhidihi. The 70 km long Kumari River falls into the Kangsabati at Mukutmanipur.

8.2.4 Bhairabbanki The Bhairab Banki originates at Ranibandh in Bankura district and flows southeast to join the Kangsabati. Its main tributary is Tarafeni.

8.2.5 Keleghai–Kapaleshwari The Keleghai or Kaliaghai River originates in the village of Kalsibhanga under Dudhkundi Gram Panchayat of Jhargram district. Then beyond Bhagwanpur and Naipur in Sabong, the river joins the Kangsabati River near Dheubhanga of Tangrakhali in Purba Medinipur district. Keleghai is a right bank tributary of Kangsabati. Keleghai has two main tributaries—Kapaleshwari and Chandia. Kapaleshwari originates at Langalkata and Chandia near Shyamchak in Sabong block and merges with Keleghai near Moyna. The confluence of Kapaleshwari and Keleghai forms a wetland called Shalmari Jala, which is inundated by river water every year during the monsoons. The combined flow of Kansabati and Keleghai is known as Haldi River.

8.3 The Myth and Keleghai The Lodha community believes that the waters of the Keleghai River are nourished by the blessings of their god Kalindi and the river Kalighai originated from the name of Kalindi. Later the name of the river is Kaliaghai or Keleghai came from the name Kalighai. In the past, there was a reservoir formed by a waterfall in the village of Kalsi Bhanga, the source of the Keleghai River, the water of which was fed by the river. But that waterfall is no more, it has been closed. Now Keleghai is

8.5 Haldi River

119

nourished by the monsoon water only. Apart from Kalindi Thakur, two other local deities are worshiped by the people along the course of the Keleghai River and they are Ma Guptomani and Debi Joychandi. Local people believe that these three gods and goddesses are brothers and sisters. Kalindi Thakur is called Kaliya Sanrh by many people of the area which can be considered as the origin of the name of the river Kaliaghai.

8.4 Illegal Soil Mining and Selling Allegations of mining and selling silt from the Keleghai riverbed have been noticed day after day. No permission was taken from block administration or district administration for harvesting soil from the tidal shoals and riverbeds of Keleghai. In the Kirtankhali area of Gurgram Gram Panchayat area of Bhagabanpur-I Block, regular action with bulldozers, tractors, matadors, and machine vans have been going on for several days. Places like Kilakhali, Mohammadpur, Deredighi, Kantakhali, and Kirtankhali along with kilometer after kilometer of the Keleghai River have been noticed for such illegal silt mining. The police are taking legal action against those caught illegally evading government taxes and unscientifically cutting and smuggling soil from the riverbank and riverbed. Unplanned excavations, construction of unplanned earthen mounds, setting up of illegal brick kilns have created an unrestrained anarchic environment in the long stretch of the banks of the vast Keleghai River. A few people oppress the quiet freshwater river Keleghai. As a result of illegal and unrestrained exploitation of river grazing, Bhagwanpur faced a terrible flood in 2021 after the dam of the turbulent Keleghai River broke. No one learned a lesson from it. As a result, the people of the area along the Keleghai River are afraid to suffer from floods again.

8.5 Haldi River Haldi river is formed from the confluence of Kangsabati and Keleghai rivers. Haldi River originates from the confluence of two rivers at Dheu Bhanga near Tangrakhali bus stand in Purba Medinipur district. Haldi joins the Hooghly River at Haldia separating Haldia and Nandigram just a few km downstream of the confluence of Rupnarayan and Hooghly rivers. The total length of the Haldi River is 24 km. The total area of Haldi River basin is 10,210 km2 . According to the plan of Dr. Bidhan Chandra Roy, the new port-city of Bengal Haldia was built near the mouth of Haldi River.

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8.6 Shifting of River Course Kangsabati is one of the tributaries of Haldi River in Purba Medinipur district. After entering Paschim Medinipur district from Bankura district, Kangsabati narrows and flows about 21 km up to Kapastikri after crossing Midnapore town. Near the Kapastikri area, the Kangsabati or Kansai River bifurcates and forms two small streams. A relatively small branch flows northward taking the name of Old Kansai. The old Kansai again bifurcates to form smaller streams called the Palaspai Canal and the Durbachati Canal. These two small streams merge with the Rupnarayan River. After the bifurcation of Kangsabati River, its main tributary known as New Kansai River flows southeast and join the Haldi River near Itamogra under Mahishadal Police Station of Purba Medinipur district. In the late eighteenth century, shortly before Panshkura, the Kangsabati or Kansai River deviated quite a bit from its old course, and it started to flow towards the south. This is the current form of the Kangsabati or Kansai River which outfalls into the Haldi River. Haldi River meets Hooghly near Haldia that ultimately joins the Bay of Bengal [22, 28].

8.7 Kangsabati Project The Kangsabati Project is a reservoir and irrigation project in West Bengal. This project is also known as Kangsabati Irrigation Scheme or Kangsabati Reservoir Scheme. The project was launched in 1956 as a part of India’s second five-year plan for the purpose of irrigation in an area of 3484.77 km2 in the present Purba Medinipur, Paschim Medinipur, Bankura and Hooghly districts. Besides the Kangsabati River, the water of Silabati and Bhairab Banki Rivers is also used for irrigation purposes in this project. As part of the project, a 38-m high and 10,098-m-long reservoir has been constructed at Mukutmanipur near Khatra in Bankura district. Another reservoir of Kangsabati built in 1872 near Midnapore town was also used for this project. Once upon a time there was dense forest on both sides of the river Kangsabati of which there is no trace of forest patches anymore. Those places on both banks of the river have now been planted with trees under the initiative of the government forest department [23, 24].

8.8 River Commons People help identify the river, people name the river, and people come forward to make the river known everywhere. For example, the confluence of Kangsabati and Kumari rivers at Mukutmanipur was not known before. After the construction of Kangsabati Dam and Reservoir in Mukutmanipur, Mukutmanipur is now one of the tourist spots where afforestation drive was taken by the government forest department

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through plantation of Acacia and Eucalyptus including natural vegetation comprising several medicinal plants [19, 25, 26]. Many films are now shot here and a few of those films have won awards at several national events and have made Kangsabati River Dam even more popular. The confluence of the Kangsabati and the Kumari is now a sight to behold in the application of technology, engineering and science. People recognize a river sharing the knowledge of science maintaining ecological balance of the entire riverine and surrounding environment for the human welfare. Along the course of the Kangsabati River at Khirai, the natural environment, scenic views, florists, agronomists, and visitors in the valley of flowers are rare despite their unique nexus. Due to its close proximity to the railway station, many tourists flock to see the flower-covered fields of Khirai during the winter season. The approach to Khirai from the National Highway is even more beautiful where flower farming can be seen on either side of the winding river Kangsabati. Khirai village is located on the banks of the Kangsabati or Kansai River where about 800 to 1000 families are engaged in flower cultivation on about 2500 acres of land. Marketable flowers are brought to Mallik Ghat market by the florists who come to Howrah by local train from Khirai Station at 3.05 am. Now flower dealers in Kolaghat buy flowers from flower growers. The flower dealers pay the flower growers in advance for the cultivation of flowers which the florists repay by selling the flowers. If there is a problem in flower cultivation due to excess precipitation during monsoon or drought in summer, or when insects attack flowers, the district agriculture officers come forward to give advice. Agricultural scientists are encouraging Khirai’s flower growers to adopt organic farming. Flower growers have realized the far-reaching benefits of organic farming. This is how the scientific approach coordinates the social understanding by which the common people living on the Kangsabati subbasin not only are benefitted but also maintain mutual interdependence between social (human) and ecological aspects i.e., the river commons [20, 21]. Floriculture has been going on in the Khirai area for many years, but people have recognized Khirai as a valley of floriculture only a few years ago. Social media popularizes Khirai on the banks of the Kangsabati River as the Valley of Flower. Therefore, social media can be considered as one of the tools to describe the river commons.

8.8.1 Khirai—A Flowery Village Khirai, standing on the bank of Kangsabati River, is known as a flowery village where the inhabitants of the small village spend their daily routine work by nurturing and nourishing flowers and flower plants. Khirai is a small village. The village is fully covered with different species of seasonal flowers during the winter. It is more reasonable to call floriculture rather than flower gardens where the flower growers take care of the flower plants from early morning. After a little while, the girls and women of the house come and start picking flowers. As soon as the afternoon sun shines a little, the girls and women of the house take care of all the housework and

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help in sorting flowers. A few of them start making garlands. In the afternoon, all the flowers and flower garlands are sold by the elders of the house to the flower shopper at the nearby flower market [27]. The village named Khirai is beautiful like flowers. Khirai village is in front of Kansai Bridge on the bank of Kangsabati River in Panskura-1 Block of Purba Medinipur District. On the road from the National Highway to Khirai, one can see a variety of seasonal flowers across the fields on both sides of the narrow Kansai River. Here, flowers grow from field after field. Khirai is actually the name of a river, and the village is named after that river. Everything here is as colorful and beautiful as a painting. There is the pure taste of Bengal, there is the real Bengal full of rivershouses-fields-people. But in the midst of everything, what drives everyone back to Khirai again and again is the life of thousands of flowers in a collection of smiles. It is a local belief that Bengal’s Valley of Flowers is Khirai. Saplings are generally planted across miles of fields on the right and left sides of the Kansai and Khirai rivers in the last week of the month of September, which from mid-December to the first half of February are carpeted with colours and stories of flowers. There are marigolds, dalia, aster, chrysanthemums, and many other unnamed flowers. Field after field is covered with a carpet of flowers. Farmers are busy with flower fields nourishment. Flowers are of course the main attraction, besides there are various birds, butterflies, grasshoppers, and insects. All in all, it can be said that during this time nature fills this Khirai valley with its form-juice-smell. Flowers are cultivated mainly in the winter season. Flower dealers buy flowers from farmers at a low price. Field after field is full of flowers during winter from November to February. Farmers use pesticides like Neem oil, Ektara, Lansergold, Ulala, Pyromite, Intrepid, Massy, Lervin, Babistin, Cabritop, Amister, Dyrenium 45 to prevent insect damage to flowers. Maintaining the health of flower plants is very important for flower production. For such growing issues of flower plants, chemical fertilizers like Urea, Potash, Suphala (1 kg suphala = NPK 15:15:15), Phosphate, bone dust (calcium phosphate), and 10–26, 10–26–26, 0050, 1744, & 1919 etc. code marked liquid fertilizers are applied as per necessity. Apart from chemical fertilizers, organic fertilizers like cow dung and Neem cake are applied for the growth of the flower plants. Some of the people’s particularly the visitor’s negligence towards this place is visible. Plucking flowers from trees, taking pictures on tree branches, picnicking in unsanctioned use of amplifier-plastic packet-excess food waste in generally beautiful areas, etc. are symbolic of human ruthlessness in the carpet of flowers. So, keeping them away will enable the place to maintain its character now and in the future. Cultivation of flowers is a source of income for the flower growers. The flowers or the flowering plants should not be damaged in any way for tourists busy with the pleasure of seeing. Farmers were not living only by cultivating rice or vegetables in the paddy field. So, farmers started cultivating flowers as an alternative to rice or vegetables several years ago. Flower cultivation started by a few now gradually spread from Khirai to the nearby villages like Do Kanda, Champa Dali etc. Gradually rose, Rajanigandha and other flowers are added to the seasonal flowers. Not only in the winter season but

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now in all other seasons almost all kinds of flowers are cultivated, especially those flowers which are in demand in the market. Now wholesale flower dealers come to every flower growing village every day. They buy flowers and send them to the Howrah flower market. Not only are the villages centered around Khirai village, but now, while passing through NH 16 nearby Khirai and other neighbouring villages, everyone can see the cultivation of flowers in many fields. At present, flower farming has changed the socioeconomic status of almost all villages along with Khirai in Panskura-1 Block of Purba Medinipur district.

8.9 River Water Characteristics 8.9.1 pH The physicochemical nature of water samples, either acidic or alkaline representing hydrogen ion activity is described by the pH scale. River water samples showing values above 7 in pH scale are alkaline and below 7 is acidic in nature [12]. A one (1) unit change of represents a change of factor 10 in the order of magnitude in pH scale i.e., water samples having pH 5 indicate 10 times more hydrogen ion activity than the samples of pH 6. In the river water, the pH level is increased for the photosynthesis due to consumption of hydrogen by the algal community and it is decreased due to physiological processes like respiration and microbial decomposition [4, 13, 14]. Lowering of pH levels indicates increasing sulfate and total organic carbon (TOC). Further, pH has a positive correlation with the DOM (dissolved organic matter) of the river waters [32]. pH of surface water samples of Kangsabati River at Gandhi Ghat of Midnapore town ranges from 6.9 to 8.22 [1].

8.9.2 Dissolved Oxygen Most of the aquatic fauna exists within the river water because it contains dissolved oxygen. The quantity of oxygen remaining in the dissolved state in the water is known as dissolved oxygen. In the riverine environment, dissolved oxygen is generally saturated through the mixing of oxygen from the atmosphere and from the process of photosynthesis of the aquatic plants including a huge algal population containing chlorophyll or other photosynthetic pigments [30, 37, 40, 44]. The dissolved oxygen is positively correlated with the rate of gross primary production where the standard value of dissolved oxygen for fisheries is 5.8 mg/l as prescribed by EPA [31]. Surface water temperature and water transparency may change the distribution of dissolved oxygen content [43]. The dissolved oxygen content of surface water samples of Kangsabati River at Gandhi Ghat of Midnapore town ranges from 7.5 to 10.8 mg/l from January to December in a year.

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Turbidity may change the physicochemical properties of river water though turbidity shows a linear relationship with the dissolved oxygen as the dissolved oxygen level rises with the increasing values of turbidity [36]. Total dissolved solid (TDS) is positively correlated with conductivity where conductivity provides estimation of total dissolved solids with more than 90% accuracy in laboratory analysis [3, 29]. Conductivity of surface water samples of Kangsabati River at Gandhi Ghat of Midnapore town ranges from 151.5 to 283 µs/cm from pre-monsoon to post-monsoon seasons. Generally higher content of biodegradable organic material can deplete the level of dissolved oxygen content due to decomposition by the metabolic activities of the microbial organisms. Such decline of dissolved oxygen content results in the higher concentration of biochemical oxygen demand. Thus, higher biochemical oxygen demand (BOD) and lower dissolved oxygen (DO) levels of river water can interpret the abundant occurrence of phytoplankton where byproducts of algal photosynthesis can replenish dissolved oxygen in the river water.

8.10 Physicochemical Parameters River water, in major cases, contaminated from non-point sources is generally determined by the values of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as both of them are considered as the indicators of river water pollution from the non-point sources [39, 42]. BOD ranges from 1.4 to 4.6 mg/l in the river water of Kangsabati River at Gandhi Ghat of Midnapore town near Hanuman Mandir [1]. COD acts like an index for that provides an assessment of effect of the effluents discharged by the industry or wastewater drained from the connecting canals of the municipalities into the river water without treatment. The values of COD are high where the wastewater generally contains a higher quantity of organic materials which are to be oxidized consuming dissolved oxygen [16]. As a result, higher COD value reduces the dissolved oxygen content [45]. COD ranges from 7.8 to 12.9 mg/l in the river water of Kangsabati River at Gandhi Ghat of Midnapore town near Hanuman Mandir [1]. The values of BOD and COD of surface water in the Kangsabati River are exceeding the permissible limit which are not suitable for outdoor bathing.

8.11 Faecal Coliform Bacteria The faecal coliform bacteria is carried into the river water through runoffs generally during the storm flow condition as a result of heavy precipitation rather than low flow condition which is revealed by the statistical measures like correlation coefficients between the number of faecal coliform bacteria, water turbidity, total dissolved solids, and flow rate particularly from the region along the river course where the wildlife habitat, farming land, or animal grazing are abundantly occurred [34, 35, 38, 41]. Number of faecal coliform bacteria ranges from 4000 to 50,000 MPN/100 ml in the

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surface water of Kangsabati River at Gandhi Ghat of Midnapore town near Hanuman Mandir [1]. The permissible limit of faecal coliform bacteria is 300 MPN/100 ml of river water for the use of domestic purposes [5].

8.12 Water Quality Indices Water quality remains almost constant for Kangsabati River from the point of view of the concentrations of biochemical oxygen demand (BOD) as recorded recently in the Central Pollution Control Board (CPCB) Report 2022 [15, 17, 18, 20]. Kangsabati River featuring Priority IV in the CPCB Report 2018 has now been categorized as the same Priority IV in the report of CPCB 2022 [5]. The status of the river remains the same in Priority IV and soon the river will be excluded from the list of polluted rivers as the biochemical oxygen demand value goes down from 9.9 mg/l in 2018 to 6.3 mg/l in 2022 [1, 2, 5]. The river water is still unusable for outdoor bathing as the CPCB prescribed standard values of BOD to be 3 mg/l or less to consider a river stretch at least fit for outdoor bathing [6–8, 32, 33]. Water quality indices are calculated based on the physicochemical parameters available in the Database on environment and forestry statistics of West Bengal, Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal, 2015 [1, 22]. Water quality improves for Kangsabati River along its course because the surface water condition of Kangsabati River is 60% good, 32% fair and only 8% poor as per water quality rating based on computed values of water quality indices (Table 8.1). Table 8.1 Water quality indices of the river water of Kangsabati at Gandhi Ghat area in the Midnapore town Sampling station

Gandhi Ghat, Midnapore

WQI of Kangsabati River Year

Pre-monsoon

Monsoon

Min

Max

Min

Max

Post-monsoon Min

Max

2013–14

36.02 (Good)

54.81 (Fair)

23.37 (Good)

44.88 (Good)

30.91 (Good)

57.91 (Fair)

2014–15

45.49 (Good)

55.36 (Fair)

43.24 (Good)

62.77 (Poor)

35.12 (Good)

58.09 (Fair)

Water Quality Rating: WQI 0–45 = Good; 45–60 = Fair; > 60 = Poor

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8.13 Summary The government had built dams on the river Kangsabati as per the needs of the local people that blocked the flow of the river. Already this river does not have any water flow throughout the year except during the rainy season. Geographically, this river has been divided again and again and narrowed in the lower course. That is why the water holding capacity of the river is low [9, 10]. In the middle course of the river, at Midnapore Town, the river water is unsuitable even for outdoor bathing. The reason for this is that the effluents from the municipal sewers in Midnapore got mixed up in the river water [11]. The number of faecal coliform bacteria is high and ranges from 2000 to 80,000 MPN/100 ml in the river water which is beyond the permissible limit. The mixing of both municipal effluents and waste materials from non-point sources is responsible for the predominance of faecal coliform bacteria in the river water.

References 1. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 2. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 3. Atekwana EA, Atekwana EA, Rowe RS, Werkema DD and Legall FD (2004) The relationship of total dissolved solids measurements to bulk electrical conductivity in an aquifer contaminated with hydrocarbon. J Appl Geophys 56(4). https://doi.org/10.1016/j.jappgeo.2004.08.003 4. Chattopadhyay B, Datta S, Chatterjee A, Mukhopadhyay SK (2001) The environmental impact of waste chromium of tannery agglomerates in the east Calcutta wetland ecosystem. J Soc Leather Tech Chem 84:94–100 5. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi 110032, p 94 6. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 7. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 8. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 9. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 10. Das GK, Datta S, Sanyal SK (2004) Need for geomorphic mapping in terms of physico-chemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 11. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 12. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9

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13. Das GK (2011) Impact of salinity and nutrients on the changing mangrove floristic—a case study from the river flood plains of Sunderbans, India (119–129). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 14. Das GK (2011) Studies on the potentiality of medicinal applications of some mangroves of Sunderbans (68–73). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 15. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 16. Das GK (2014) Environmental scenario of Sunderbans: planning and management (1–24). In: Anthropecology and applied biodiversity. OmniScriptum GmbH & Co. KG, Saarbrucken, Germany, p 408 17. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN 978-3-319-11342-5 18. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN 978-3-319-44190-0 19. Das GK (2019) Medicinal plants around wetlands in Sunderbans. Frontier 1–3 20. Das GK (2020) Forest covers of West Bengal: a district wise review. Reason Tech J XIX:26–63. https://doi.org/10.21843/reas/2020/26- 63/209272 21. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1 22. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 23. Das GK (2022) Eucalyptus plantation in Badlands. Indian Sci Cruiser 36(2):8–9 24. Das GK (2022) Environmental feasibility test for Eucalyptus plantation applying statistical methods. Indian Sci Cruiser 36(2):52–53 25. Das GK (2022) Mahua tree and its products. Indian Sci Cruiser 36(4):11–12 26. Das GK (2022) Interference in the Elephant corridor: its effect and mitigation. Indian Sci Cruiser 36(4):13 27. Das GK (2022) Khirai–a flowery village. Indian Sci Cruiser 36(6):10–11 28. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 29. Day BA, Nightingale HI (1984) Relationships between ground-water silica, total dissolved solids, and specific electrical conductivity. Groundwater 22(1):80–85. https://doi.org/10.1111/ j.1745-6584.1984.tb01479.x 30. Doubek JP, Carey CC, Cardinale BJ (2015) Anthropogenic land use is associated with N-fixing cyanobacterial dominance in lakes across the continental United States. Aquat Sci 77(4):681– 694. https://doi.org/10.1007/s00027-015-0411-x 31. EPA (2000) Ambient aquatic life water quality criteria for dissolved oxygen (saltwater): Cape Cod to Cape Hatteras. United States Environmental Protection Agency Narragansett, RI, p 144. ISBN-13: 978-1249856160 32. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 33. Ewing GN (1985) Instrumental method of chemical analysis. McGraw Hill Book Company, New York, p 624. ISBN 978-0070198517 34. Fries JS, Characklis GW, Noble RT (2006) Attachment of fecal indicator bacteria to particles in the Neuse River Estuary, N.C. J Environ Eng 132(10). https://doi.org/10.1061/(ASCE)07339372(2006)132:10(1338) 35. Kim G, Choi E, Lee D (2005) Diffuse and point pollution impacts on the pathogen indicator organism level in the Geum River, Korea. Sci Total Environ 350(1–3):94–105. https://doi.org/ 10.1016/j.scitotenv.2005.01.021 36. Liao BQ, Lin HJ, Langevin SP, Gao WJ, Leppard GG (2011) Effects of temperature and dissolved oxygen on sludge properties and their role in bioflocculation and settling. Water Res 45(2):509–520. https://doi.org/10.1016/j.watres.2010.09.010

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37. Lv H, Yang J, Liu L, Yu X, Yu Z, Chiang P (2014) Temperature and nutrients are significant drivers of seasonal shift in phytoplankton community from a drinking water reservoir, subtropical China. Environ Sci Pollut Res 21:5917–5928. https://doi.org/10.1007/s11356-0142534-3 38. Mallin MA, Johnson VL, Ensign SH (2009) Comparative impacts of stormwater runoff on water quality of an urban, a suburban, and a rural stream. Environ Monit Assess 159:475–491. https://doi.org/10.1007/s10661-008-0644-4 39. Miltner RJ, Rankin ET (1998) Primary nutrients and the biotic integrity of rivers and streams. Freshw Biol 40(1):145–158. https://doi.org/10.1046/j.1365-2427.1998.00324.x 40. Paerl HW, Hall NS, Calandrino ES (2011) Controlling harmful cyanobacterial blooms in a world experiencing anthropogenic and climatic-induced change. Sci Total Environ 409(10):1739– 1745. https://doi.org/10.1016/j.scitotenv.2011.02.001 41. Sanders EC, Yuan Y, Pitchford A (2013) Fecal coliform and E. coli concentrations in effluentdominated streams of the upper Santa Cruz watershed. Water (Switzerland) 5(1):243–261. https://doi.org/10.3390/w5010243 42. Sheiham I (1981) Water chemistry. Water Res. https://doi.org/10.1016/0043-1354(81)90032-4 43. Stefan HG, Fang X, Wright D, Eaton JG, Mccormick JH (1995) Simulation of dissolved oxygen profiles in a transparent, dimictic lake. Limnol Oceanogr 40(1):105–118. https://doi. org/10.4319/lo.1995.40.1.0105 44. Xu H, Paerl HW, Qin B, Zhu G, Gao G (2010) Nitrogen and phosphorus inputs control phytoplankton growth in eutrophic Lake Taihu, China. Limnol Oceanography 55(1):420–432. https:// doi.org/10.4319/lo.2010.55.1.0420 45. Yao N, Wang J, Zhou Y (2014) Rapid determination of the chemical oxygen demand of water using a thermal biosensor. Sensors 14(6):9949–9960. https://doi.org/10.3390/s140609949

Chapter 9

Water Quality Determinants of Mathabhanga, Churni and Jalangi Rivers

Abstract Industrial manufacturers like sugar mills and distillery plants, and milk units drain waste effluents into the waters of Mathabhanga, Churni and Jalangi rivers of Nadia district in West Bengal. Apart from industrial effluent discharge, Mathabhanga, Churni and Jalangi rivers receive domestic sewage on a regular basis through drainage systems from Majdia town, Ranaghat and Krishnanagar municipalities respectively. The wastewater effluent and domestic sewage affect the aquatic environment resulting in drastic changes in the river water quality of Mathabhanga, Churni and Jalangi rivers which are deleterious to both aquatic flora and fauna and this is how most of the river stretches of Mathabhanga, Churni and Jalangi got polluted. For the determination of the magnitude of pollution, the water quality index of river water is computed. The obtained result reveals that the present condition of surface water of Mathabhanga and Churni is in worse condition where the situation of Jalangi River at its downstream is comparatively better. Keywords Churni · Anjana · Jalangi · Mathabhanga · Ichhamati · Water quality index · Physicochemical parameters

9.1 Churni–Mathabhanga–Ichhamati River Systems All the rivers of Nadia and North 24 Parganas districts of West Bengal are interconnected comprising the Mathabhanga–Churni–Ichhamati River systems where Jalangi is connected with Churni through the course of Anjana River.

9.1.1 Churni and Jalangi Churni and Jalangi rivers of Nadia are the two main waterways of the district, of which the Jalangi River is the longest (Figs. 9.1 and 9.2). Jalangi flows through Murshidabad and Nadia districts for about 233 km and joins Bhagirathi River at Swarupganj near

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_9

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Fig. 9.1 Blackish water flow along the course of Churni River at Aranghata of Nadia district, West Bengal

Mayapur. Jalangi is thus a tributary of Bhagirathi River. Jalangi originates from the Padma River in Murshidabad district and so, Jalangi is a distributary of Padma River. On the other hand, the Churni River originates from Mathabhanga River near Majdia in Nadia district and flows about 56 km to join the Bhagirathi River at Shibpur near Payradanga of the same district. The river Mathabhanga bifurcates to form Churni and Ichamati rivers at Majdia. It is said that King Krishnachandra of Nadia dug a canal from Majdia to Krishnaganj in the seventeenth century to escape Bargi raids. This canal later took the form of the Churni River. It may also be that a canal was cut from the Mathabhanga River which morphs into the Churni River. The geographical

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reason behind the cut canal becoming a river is the local subsidence which stabilized later in the seventeenth century. For this reason, although almost all the rivers here flow in the south-east direction, the Churni and Jalangi rivers flow in the south-west direction which bears the evidence of the young age of these two rivers [20].

Fig. 9.2 Jute processing by the local farmers in the river waters of Jalangi at Krishnanagar downstream in Nadia district of West Bengal

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9 Water Quality Determinants of Mathabhanga, Churni and Jalangi Rivers

9.1.2 Anjana A river called Anjana connects Jalangi and Churni rivers almost at right angles. The length of Anjana River is only 23 km which has lost its current earlier and it is now in crisis of existence. Due to the navigability of this river at one time, it was very convenient to travel by water. But when Muslim invaders started using this waterway, Raja Krishna Chandra’s predecessor Raja Rudra Ray blocked the source of the Anjana River. Later, during the British period, an attempt was made to control the flow of water by installing sluice gates on the source point of Anjana River from Jalangi River. At present, the urban people of Krishnanagar are making illegal constructions on the riverbank of Anjana, just like the farmers in the villages have started cultivating on the filled in riverbed of Anjana River. The Anjana River gradually became sick due to the repeated obstruction of the flow of water in the course of the river. Now no flow is seen across the course of the river. Almost all the river is covered with aquatic weeds and this river is now standing on the verge of extinction (Fig. 9.3). The encroachers are not only cultivating paddy in the riverbed but also making ponds for fish farming round the year in the river floodplain along its course [20]. The Anjana River had its origin for other reasons. In the estuary at Swarupganj near Mayapur, the water level of the Jalangi River is below the water level of the Bhagirathi River and that is why the water of Jalangi River cannot mix with Bhagirathi River. Then the water of Jalangi River started to flow backwards and flow through a slope. This is how the Anjana River originated as a tributary of the Jalangi River.

9.1.3 Mathabhanga Mathabhanga River, source of Churni River, originates from Padma in Munshiganj, Bangladesh and enters Indian territory. Carew & Company discharges all its factory waste effluents into the Mathabhanga River 4–6 times a year near Darshana in Bangladesh without any wastewater treatment. After dumping the polluted waste into the river, the effluent from the Mathabhanga River mixes with the water of the Churni River and within two to four days, the entire Churni River water turns black. Then all the fish floated in the Churni River and died later, and river water became unfit for all kinds of domestic use including outdoor bathing and washing clothes and utensils. Similarly, a milk company named The Kishan Cooperative Milk Producer Union Ltd drains its wastewater into the Jalangi River which pollutes the river water. Also, in the lower reaches of the two rivers, Ranaghat and Krishnanagar Municipalities discharge wastewater through municipal drainage systems. Simultaneous discharge of industrial effluent and municipal wastewater degrades the quality of river water. Mathabhanga River is the most polluted river that starts its journey from Padma River in Bangladesh. After entering in India near Gede international border

9.1 Churni–Mathabhanga–Ichhamati River Systems

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Fig. 9.3 Anjana River at Badkulla of Nadia district covered with water hyacinths

areas and flowing for a few kilometers, Mathabhanga River bifurcates to form Churni and Ichhamati rivers near Majdia of Nadia district of West Bengal [20].

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9.1.4 Ichhamati Ichamati River originates from Mathabhanga River in the Majdia area of Nadia District of West Bengal. Ichamati River is a transboundary river of Bangladesh and West Bengal. The river flows through Chuadanga, Jhenaidah, Jessore and Satkhira districts of Bangladesh and North Twenty-four Parganas district of West Bengal, India. The river has a length of 334 km and an average width of 370 m. In Ichamati, where in the past boats used to ply, regular tides play, there are now two or four broken boats lying on the banks of the river. However, the Basirhat-Hasnabad region still experiences tidal flow in the Ichamati River. Along the course of river, somewhere in Ichamati, a road has been built over the river, some where the water level has accumulated and the water level has not fallen, and somewhere else paddy cultivation has started on the riverbed. Ichamati is in such a state of losing current and velocity. The Ichamati not only flows in India but also enters Bangladesh after crossing a path of 20 km from Majdia and entering Bangladesh near Mubarakpur. After that, it flowed 35 km in Bangladesh and returned to Indian territory at Duttapulia. After crossing Nadia district, the Ichamati passes 43 km in North Twenty-four Parganas and enters subdivisional town of Bangaon and from there flows southwards through Angrail to Beri Gopalpur for 21 km along the Indo-Bangladesh border. Yamuna River flows for another 10 km from Beri Gopalpur and joins Ichamati River at Tipi. From Tipi, Ichamati reaches Hasnabad through Tentulia, Basirhat, Goalpara, and Taki. Ichamati is divided into two parts. Its western branch flows southwards as the Hasnabad canal and joins the Bidyadhari through Malancha and Raimangal to the sea. The main branch goes through Hingalganj and joins the sea near the mouth of the Kalindi River in the Sundarbans. However, the 133 km stretch from Majdia to Beri Gopalpur is now full of streamless watercourses and covered with aquatic weeds and water hyacinths. About 19.5 km of course of Ichamati from Pabakhali to Fatehpur is currently almost plain land due to accumulation of silt in the waterless riverbed. There is now paddy cultivation in the riverbed and floodplains. Due to loss of source of Ichamati, flood situation occurs in vast areas of Dattafulia, Bangaon, and Basirhat during heavy rains. There is no end to the misery of people leaving their homes during flood situations. On the one hand, as there is no water in the river during hot season, the farmers cannot use the river water for irrigation purposes. On the other hand, the surrounding areas are flooded due to a little heavy rain, causing huge damage to the crops. At its source near Majdia town of Nadia district, Ichamati riverbed is 14 feet higher than Mathabhanga, while Churni is six inches lower than Mathabhanga. During the dry season the headwaters of the Mathabhanga are higher than the Padma and as a result no water enters the Ichamati during this period. One of the causes of siltation in the river is the construction of guard walls in the river by railway overbridges near its source. Riverbed excavation is essential in the area particularly at source as there is flow of water of Mathabhanga even during dry season [20].

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9.2 Commons of Riverside Countries Immersion of Durga idols at Ichamati is a century-old custom which seems to be river commons of both countries for India and Bangladesh. The Ichamati River defines the border between India and Bangladesh at Taki of North 24 Parganas. People from outside the state or country come to Taki of Basirhat to witness this idol immersion from the riverside of both countries. There are completely different emotions and feelings around this abandonment of the people of Bangladesh and Bengal in India. As so many people come, the border guards of both countries are also more active. The idol is immersed in the Ichamati River of Taki. India is located on this side of the Ichamati River and Bangladesh is on the other side. Many people framed the scene of Goddess Durga going to Kailash by boat. Durga idol of Puber Bari was given the first immersion. Since then, one by one, various idols of the area have boarded boats and floated around the river water in Ichamati.

9.3 Physicochemical Parameters Uses and utilization of river waters are generally determined by some selected physicochemical parameters like pH, conductivity, DO, BOD, COD, TDS, TSS, TFS, TA, TH, calcium, magnesium, faecal coliform etc., and water quality index are computed averaging weight of some of the selected water parameters like pH, conductivity, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, total fixed solids, total alkalinity, and total hardness according to their significance and importance in a particular environment [19]. In the present study, water quality index (WQI) is calculated applying the standard statistical formula considering the minimum and maximum values of individual physicochemical parameters of Churni, Jalangi, and Mathabhanga rivers based on Database on environment and forestry statistics of West Bengal [2]. After computation of water quality index, water quality rating is determined on the obtained values of WQI.

9.4 River Water Characteristics A sugar manufacturing and distillery unit named Carew and Company at Darshana of Bangladesh discharges industrial effluent into Mathabhanga River that enters Churni River in India. Like Carew and Company, The Kishan Co-operative Milk Producers’ Union Ltd of Nadia district discharges wastewater effluent in Jalangi River. Generally, three types of adverse effects are observed when the river water receives the wastewater from the canals or drainage systems that flow directly from the industrial plants, municipality, or urban areas. Physical pollution is interrelated with the changes in

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turbidity, temperature, water colour including several other surficial properties [1, 2]. Organic or inorganic nutrient pollution is caused by oxygen depletion or eutrophication [13, 15, 16]. Chemical pollution happens due to the changes of toxicity, acidity, alkalinity, or salinity alterations which are determined by the laboratory analysis of pH, conductivity, DO, BOD, COD, TDS, TSS, TFS, TA, TH, and microbiological water pollution is considered with the availability of the most probable number (MPN) of microbial organisms like faecal coliform or total coliform bacteria in the surface waters of the rivers [29–31]. Industrial water effluents mixed in the Mathabhanga River water at Darshana of Bangladesh contaminate river waters of Churni though a portion of the riverbank of Mathabhanga is covered with bushes and jungles near Gede border areas [17, 18]. Like sugar manufacturing plants of Bangladesh, The Kishan Cooperative Milk Producer Union Ltd discharges wastewater effluent into Jalangi that pollutes the river waters. The rivers of West Bengal are generally alkaline and have an influence on climate change mitigation by absorbing atmospheric carbon dioxide [12, 21]. For the analysis of BOD, two factors like temperature and time are very important to obtain accurate and reproducible results [25, 26]. Like BOD, the occurrences of microbial populations are influenced by the availability of dissolved oxygen, temperature, pH, and ultimately the composition of wastes and sewage released in the river water [4, 6]. COD analysis is concerned with rigorous chemical oxidation and for this reason, COD values show no relationship with that of BOD [14, 27]. For wastewater treatment, chemical parameters of the river water like pH, conductivity, DO, BOD, COD, TDS, TSS, TFS, TA, TH, TKN etc. are to be standardized to the permissible limit for domestic or agricultural usage [24]. River water has a greater concentration of dissolved solids as part of direct run-off enters the river system soon after precipitation in the form of rain [7–9]. Some dissolved substances in the form of total dissolved solids are present in the natural uncontaminated river waters [10, 11]. TDS, TSS, and TFS values are rather higher for the river water of Mathabhanga in the upstream than that of Churni River in the downstream only except a few exceptional cases [28]. Huge quantity of wastewater drained by the sugar and distillery plant of Bangladesh into the water of Mathabhanga River is carried to Churni River that causes decomposition of Cyanobacteria existing in the river water. The process of decomposition results in huge consumption of dissolved oxygen that leads to hypotoxic conditions of the surface water of the Churni River [23]. The river water almost lacking dissolved oxygen along with the decomposed algal materials lead to turn the colour of the river water black [20]. The blackish condition of river water persists at least a fortnight until the river water gains again the minimum content of dissolved oxygen duly saturated through the air–water interaction in the fluvial environment [5].

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9.5 Water Quality Index Surface water condition of the river is generally determined by the Water quality index (WQI), which is computed by averaging the relevant values of physicochemical parameters of the water samples. The Water Quality Index is considered as the water quality determinant which is likely to be significant for the interpretation of the present conditions of the water bodies. Values of the computed water quality index revealed that the water quality rating indicating about 25% good, 66% poor, and only 9% fair water conditions of Mathabhanga River as per standard water quality rating chart during three principal seasons of South Bengal i.e., pre-monsoon, monsoon, and post-monsoon in a year is not suitable for outdoor bathing that contains 66% poor surface water (Fig. 9.4). After computation of water quality indices of Churni River, the values show that the surface water contains about 25% good, 25% fair, and 50% poor water as per water quality rating chart issued by the Central Pollution Control Board (CPCB). Computed water quality index indicates that the surface river water of Jalangi River containing about 58% good, 34% fair, and only 8% poor water is at least suitable for outdoor bathing as per standard water quality rating chart of the Central Pollution Control Board (Fig. 9.4). The values of water quality indices revealed that the water quality of Jalangi River is rather better than that of Churni and Mathabhanga rivers as reflected by the calculated WQI values. Computed values of water quality indices reveals that the condition WATER QUALITY INDEX Pre-monsoon

Pre-monsoon

Monsoon

Monsoon

Post-monsoon

Post-monsoon

WATER QUALITY INDEX

90 80 70 60 50 40 30 20 10 0

2013-14

2014-15

2013-14

MAJHDIA

2014-15

RANAGHAT CHURNI

2013-14

2014-15

2013-14

2014-15

GOBINDAPUR

KRISHNANAGAR

MATHABHANGA

JALANGI

Fig. 9.4 Water quality indices of the surface water samples of Churni, Mathabhanga and Jalangi rivers

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of surface water of Jalangi River is almost in good condition and suitable for outdoor bathing only except the month of January 2015 where the surface water quality shows poor water conditions during the post-monsoon period. At Krishnanagar of Jalangi downstream, the water quality indices values support good and fair water conditions. Despite such favourable values of water quality indices, the water of Jalangi River is not usable because of the prolific presence of faecal coliform bacteria and their number is very high that crosses beyond the permissible limit as per standard values directed by the Central Pollution Control Board. After the analyses of water samples, the most probable number of faecal coliform bacteria varies from 4000 to 110,000 per 100 ml of surface water samples in 2015 which is declined to only 400 MPN/100 ml in 2020 after rigorous treatment of municipal sewage in eight drains of Krishnanagar municipality before their release into Jalangi River.

9.6 Summary The criteria of polluted surface water are determined by BOD values and MPN of faecal coliform bacteria present in the river waters. In Jalangi River, the BOD value ranges from 1.05 to 5.6, 1.0 to 6.0, and 1.6 to 5.7 mg/l in 2017, 2018, and 2019 respectively [3]. For this reason, water quality is poor a little bit for the bacterial number and higher content of BOD [22]. After primary treatment initiated by the River Rejuvenation Committee since September 2019 applying screens and sedimentation tank on Jalangi River, the BOD value ranges from 2.0 mg/l in February 2020 to 3.25 mg/l in the month of May 2020 with only an exception of 6.35 mg/ l in the month of March 2020. Similarly, the faecal coliform bacteria in the river water of Jalangi varies from 33,000 to 3,00,000, 4000 to 5,00,000, 2000 to 5,00,000 MPN/100 ml during 2017, 2018, and 2019 respectively. But after sewage treatment like chlorination on the mouths of all municipal drains, the faecal coliform bacterial numbers declined to 400 MPN/100 ml in the month of May 2020 that leads to almost fit for outdoor bathing in the river water of Jalangi. But the water quality of Mathabhanga and Churni rivers will be remaining the same until and unless the sugar manufacture and distillery plant under the Bangladesh Government takes a drastic step for the treatment of industrial wastewater effluent before its discharge into Mathabhanga River.

References 1. Anonymous (1996) Standards for liquid effluents, gaseous emissions, automobile exhaust, noise and ambient air quality. Central Pollution Control Board (CPCB), Ministry of Environment and Forests, Government of India, Pollution Control Law Series, PCL/4/1995-96 2. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal

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3. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 4. Bartha C, Jipa M, Caramitu AR, Voina A, Tókos A, Circiumaru G, Micu DD, Lingvay I (2022) Behavior of microorganisms from wastewater treatments in extremely low-frequency electric field. Biointerface Res Appl Chem 12(4):5071–5080. https://doi.org/10.33263/BRIAC124.507 15080 5. Brooks BW, Lazorchak JM, Howard MDA, Johnson MVV, Morton SL, Perkins DAK, Reavie ED, Scott GI, Smith SA, Steevens JA (2016) Are harmful algal blooms becoming the greatest inland water quality threat to public health and aquatic ecosystems? Environ Toxicol Chem 6. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi 110032, p 94 7. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 8. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 9. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 10. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 11. Das GK, Datta S, Sanyal SK (2004) Need for Geomorphic mapping in terms of physicochemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 12. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 13. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, pp 1–254. ISBN 81-87169-72-9 14. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 15. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, pp 1– 211. ISBN 978-3-319-11342-5 16. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, pp 1–51. ISBN 978-3-319-44190-0 17. Das GK (2019) Medicinal plants around wetlands in Sunderbans. Frontier 1–3 18. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, pp 1–231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1 19. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 20. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 21. Das GK (2023) Water quality index of Churni and Jalangi rivers, West Bengal, India. Int Res J Environ Sci 12(1):14–18 22. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 23. Galal Uddin Md, Nash S, Agnieszka I, Olbert A (2021) Review of water quality index models and their use for assessing surface water quality. Ecol Indicators 122:107218. https://doi.org/ 10.1016/j.ecolind.2020.107218 24. Langone M, Sabiab G, Pettab L, Zanettic L, Leonic P, Bassoc D (2021) Evaluation of the aerobic biodegradability of process water produced by hydrothermal carbonization and inhibition effects on the heterotrophic biomass of an activated sludge system. J Environ Manage 299. https://doi.org/10.1016/j.jenvman.2021.113561

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25. Muralikrishna IV, Manickam V (2017) Analytical methods for monitoring environmental pollution, environment management, pp 495–570. https://doi.org/10.1016/B978-0-12-811989-1.000 18-X 26. Subramanian V (2011) A textbook of environmental chemistry. I.K. International Publishing House Ltd., New Delhi, pp 1–482. ISBN 978-93-81141-19-9 27. Tyagi VK, Lo SL (2016) Energy and resource recovery from sludge: full-scale experiences, environmental materials and waste, resource recovery and pollution prevention, pp 221–244. https://doi.org/10.1016/B978-0-12-803837-6.00010-X 28. Weide T, Brügging E, Wetter C (2019) Anaerobic and aerobic degradation of wastewater from hydrothermal carbonization (HTC) in a continuous, three-stage and semi-industrial system. J Environ Chem Eng 7(1). https://doi.org/10.1016/j.jece.2019.102912 29. WHO (2004) Health risks from drinking demineralized water. WHO, USA 30. WHO/UNICEF (2005) Water for life: making it happen. ISBN 92-4-156293-5 31. WRN (2016) pH in the environment. Available from http://www.water-research.net/index.php/ ph-in-theenvironment. Accessed 3 Jun 2016

Chapter 10

River Environments of North Bengal

Abstract The rivers of North Bengal are perennial and generally carry rain and snow water from the upland hilly region that flow to the downstream plains. This natural flow of the rivers of mountainous origin with a more or less stable state of equilibrium is considered as natural waterways. But the flows of such natural waterways are interrupted by the gradual reduction of carrying capacity that accommodates the river discharge from the upland areas due to human encroachment of the part of the riversides and floodplains. Apart from the reduction of the accommodation capability, the increase of rainfall including the snow-melt water for current issues like global warming due to climate change causes huge discharge into the rivers of North Bengal by which the state of equilibrium is not maintained. Destruction of riverside forests and conversion of forest lands into tea estates, agricultural lands, human habitation etc. is another problem that is accelerating soil erosion and spilling over the banks resulting in flooding. Changing river courses into new fluvial inlets sometimes causes avulsion of rivers where the main river channel becomes abandoned. Concrete bridges for roadways including railway bridges over the rivers contract the river course, a narrow one for its natural flow that sometimes causes flooding in the area. Apart from these, there are several towns and municipalities along the banks of rivers in North Bengal that discharge sewage from municipalities. The sewage along with wastewater enters the river water causing it unusable even for outdoor bathing. For this reason, Paharpur to Siliguri is the polluted stretch of Teesta in 2018 and along Sevoke during 2022 in the category of Priority-V as demarcated by the Central Pollution Control Board. Keywords River systems · River commons · River environments · Water quality indices · Changing river courses · Canals and barrages

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_10

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10.1 North Bengal Rivers Most of the rivers in North Bengal originate from the hilly regions of Sikkim, Bhutan, Tibet, and Darjeeling. The major rivers of North Bengal belong to the Brahmaputra and Ganges basins. The Brahmaputra basin consists of Teesta, Torsa, Jaldhaka, Kaljani, Raidak, and Sankosh. And in the Ganga basin there are Mahananda, Kulik, Nagar, Tangan, Punarbhava, Kalindi etc. These rivers are overflowing due to heavy rainfalls that lead to landslides in hilly areas and severe floods in plains, mainly in North Bengal because the Himalayan mountainous region in the state of West Bengal has an annual rainfall of 3000–6000 mm. North Bengal is characterized with very heavy precipitation particularly in the hilly region during the entire monsoon. Simultaneous huge rainfall in the upland areas for a long period and local heavy precipitation cause high velocity of the rivers of North Bengal at the upstream in the hilly region. But huge quantities of boulders, cobbles, pebbles, sands and silt drifted with the flow of the river and accumulated in the plain, results reduction of velocity due to decrease of gradient of riverbed from 40 m/km in the hilly region to only 0.70 m/km in the plains in the North Bengal. Implementation of projects on various rivers for the development of North Bengal through increase in production of food crops, applying irrigation system, generation of hydropower for domestic and industrial development, creation of long waterways, flood control etc. is in progress. Apart from these, emphasis is being given to irrigation works in agricultural land through other small projects by mitigating flood intensity in villages and towns, reduction of soil erosion, efforts to maintain the course of drought-prone rivers etc.

10.2 River Systems The major rivers of North Bengal are Teesta, Torsa, Jaldhaka, Raidak, Kaljani, and Sankosh including some important rivers like Turtur, Gadadhar, Cheko, Saphia Khola, Kalkut, Nonai, Kaljani, Holong, Torsa, Ekti, Birbiti, Dimdima, Diana, Murti, Mal, Tunbunia, Chaiti, Jayanti, Malangi in their river systems. Most of the rivers of North Bengal originate from the hills and are covered with forest on both sides of the rivers on their way to the plains [9, 14, 15]. After proceeding through the plains, most of the rivers of North Bengal merge into the Brahmaputra and the remaining rivers outfall into the Ganges which eventually flows into the Bay of Bengal [12, 13, 18].

10.2.1 Karala Karala is a tributary of the Teesta River. The river originates at the Baikunthapur jungle in Rajganj area of Jalpaiguri district. It flows through Jalpaiguri district for

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about 40 km and outfalls into Teesta River near Jalpaiguri town. A large volume of water encompassing about 140 km2 area drains into the Teesta River through Karala River. The Karala River is navigable along its entire course. The river bisects the town of Jalpaiguri, an industrial trade center, and flows through the middle of the town.

10.2.2 Jaldhaka Jaldhaka River is a transboundary river. This 186 km long river originates from the Himalayas in South-East Sikkim, passes through Bhutan, crosses Darjeeling, Jalpaiguri and Cooch Behar districts of West Bengal and enters Bangladesh bisecting Lalmonirhat district. After entering into the Dharla River, it joins the Brahmaputra near Kurigram taking the name of Dharla. Jaldhaka, a tributary of Brahmaputra, is also known as Dichu. A hydroelectric power station has been set up on the Jaldhaka River at Bindu on the Bhutan–India border. After entering Bangladesh, the Jaldhaka joins the Brahmaputra River. Jaldhaka like Teesta River also floods almost every year during August–September in the monsoon period.

10.2.3 Raidak The Wang Chhu or Raidak River originates from the Himalayas. The river is known as Thimphu Chhu upstream. The main river is a fast-flowing river. Its motion continues on rocky riverbeds. The course of this river is very narrow between the confluence of Thimphu Chhu and Paro Chhu rivers. But then this path expanded. There it flows through very steep slopes. It then flows southeast into a relatively open valley. Several small rivers join this river from nearby hilly areas. Ta Chhu, one of the main tributaries of this river upstream of Paro Dzong joins it on the left side. Ha Chhu joins this river on the west side. At Tashichho Dzong, the riverbed elevation is 2121 m but where the river enters the Dooars, this is only 90 m above sea level. After entering Dooars in Alipurduar district of West Bengal, the river flows over Cooch Behar district. Raidak joins the Brahmaputra River in Kurigram district of Bangladesh. The name of this river in this region is Dudhkumar River. The unit length of the Raidak river course is 370 km. However, the length of this river is 610 km in Bhutan alone with the branch rivers.

10.2.4 Sankosh Sankosh River flows through India’s Assam state and Alipurduar and Cooch Behar districts of West Bengal. The Sankosh River basin area is quite large. The river

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originates in the Himalayas of Bhutan. The name of this river in the mountains is Mo Chhu. The Sankosh River descends from the mountains to the south of Deorali Gaon. This river flows along the border of Goalpara and Cooch Behar districts. The Wang, a tributary of Sankosh, coming down from the western side of Bhutan joins the Sankosh River at the border of Cooch Behar and Goalpara. This combined stream joins the Brahmaputra south of Dhubri taking the name Gadadhar.

10.2.5 Torsa The Torsa River originates in the Chumbi Valley of Tibet. The length of this river is 358 km and the area of the basin is about 4883 km2 . The name of Torsa River in Tibet is Machu. After crossing the 113 km flow path and entering Bhutan, this river was named Amochu. Torsa has crossed another 145 km lower flow path and down into the plains of West Bengal. 50% of the total flow path of Torsa falls in Bhutan and Tibet. The main tributaries of Torsa are Halong and Kaljani.

10.2.6 Kulik Kulik River is the lifeline of district headquarters Raiganj (Fig. 10.1). Kulik originates from the lower reaches of Thakurgaon village in Dinajpur district of Bangladesh and flows in the south direction. Then the river flows over places like Pirganj and Rani Shankail under Dinajpur district of Bangladesh and enters Uttar Dinajpur of West Bengal. After that, the Kulik flows through Hemtabad and Raiganj areas and joins the Nagar River at Bishahar village, about 11 km southwest of Raiganj Sadar in Uttar Dinajpur district.

10.2.7 Nagar Nagar River is one of the most important tributaries of Mahananda River. It is a trans-boundary river. The river originates in Bangladesh and after crossing about 130 km in Bangladesh, it flows through West Bengal in India. After entering West Bengal from Bangladesh, the river crosses quite a distance in Uttar Dinajpur district and later joins the Mahananda River. The Nagar River joins the Kulik River shortly before joining the Mahananda River. The combined streams of Kulik and Nagar flow in the south direction taking the name of Nagar.

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Fig. 10.1 Kulik River—the habitat for the traditional local fishes near Raiganj town in Uttar Dinajpur district

10.2.8 Mahananda and Kalindi Kalindi River connects Phulhar River with Mahananda River in Malda district of West Bengal. Mahananda River divides Malda district into two parts. The eastern part is divided by flood plains. It consists of old alluvium. Here a few hills can also

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be seen. This area is known as Barendrabhumi and it is a part of the Gangetic delta region. The western part consists of new alluvium. In this part Kalindi River joins Mahananda River. The territory north of the Kalindi River in Malda is very familiar and is called Tal. It is a lowland area. Here many swamps and bills can be seen. The fertile section south of the Kalindi River is called Diara.

10.2.9 Atreyi Atreyi River is the lifeline of Balurghat town of Dakshin Dinajpur district. This river has many unknown histories including known-unknown stories. Making its own course it is still flowing continuously. The river is described in the Mahabharata, Devi Purana, and Rabindranath Tagore’s Chinno Patrabali. Atreyi river is the passion of Dakshin Dinajpur. Atreyi is the longest river in Dakshin Dinajpur district with a length of about 58 km from Kumarganj border in the north to Dangi border in Balurghat in the south. At present, Atreyi flows through Bangladesh from the south through Samjia in Kumarganj of this district. Through Balurghat, it flows through ‘Chalanbil’ of Rajshahi district of Bangladesh and joins with Kartowa and ultimately merges into Padma River. Once the Teesta River descends from the Darjeeling Hills and flows over Jalpaiguri District, three tributaries emerge from the southern side of the Teesta River. Its middle branch is the source of the Atreyi River. Later, a devastating flood changed the course of the Teesta due to a massive landslide. Atreyi breaks up with Teesta. As a result, the river Atreyi was deprived of its main watercourse.

10.3 Shifting of River Courses During the late 1700’s, Teesta River was divided into three channels near Jalpaiguri. These channels were Dhepa Punarbhaba that flowed to the southwest, Atrai to the south and Jamuna to the southwest and all the branches discharged into Ganga which indicated that the Teesta River was then within the Ganga River system. Atrai River was then the main channel followed by Punarbhaba which was considered as secondary important channel and Jamuna was about to go to the way of extinction as per Rennel’s map of 1770. During that period, near Jalpaiguri, a less important channel of Teesta, namely Teesta Creek flowed southeast from Atrai River. Once ignored as an abandoned channel in Rennel’s map, Teesta Creek, now Teesta River at present flows with the full capacity receiving water load from Atrai, Punarbhaba, and Jamuna in the Teesta system that ultimately outfalls into Brahmaputra River in Bangladesh. A flood over Jalpaiguri and its surrounding areas in 1787 changed the course of the river all of a sudden. Geologically, underground diastrophism caused subsidence in the Gangetic Delta that forced Teesta waters towards Brahmaputra

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system and as a consequence, comparatively the old channels are left waterless conditions. In the same region of North Bengal, Torsa River was divided into two channels viz. Char Torsa and Sil Torsa and it used to flow as separate channels after bifurcation below the Hasimara area. Before 1954, the eastern channel Sil Torsa was the major channel receiving the main share of water of Torsa. A flood in 1954 changed the channel course and from then the western channel Char Torsa started flowing, taking the greater quantum of discharge. Another flood in 1957 resulted in further changes by rejuvenating Sil Torsa into the state of the channel prior to 1954 and by 1964 Sil Torsa once again became the main channel that has been carrying a major load of discharge of the Torsa system.

10.4 River Commons According to local belief, the region on the left side of the Teesta River is the Terai and the region on the right is the Dooars. River Teesta has changed its course many times. Apart from the Teesta River, North Bengal has many other rivers like Torsa, Raidak, Jaldhaka, Kaljani, Mahananda, Sankosh etc. and North Bengal is the alluvial zone of these rivers. The nature of soil of Terai and Dooars of North Bengal is almost similar. There are at least 150 tea gardens in the Dooars area. But the taste and flavour of tea here is not so good. This tea is exported abroad. Pineapples are grown in the plains of Dooars. People of South Bengal call it the pineapple of Siliguri. Also, factories making tea boxes and match boxes can still be seen here. In the tea plantations, mainly the tribals are involved in planting tea seedlings, collecting tea leaves, and processing tea. Dense forests can be seen along almost every river in North Bengal. Wild animals sometimes come near the houses of people living along rivers or forests. It is also seen that a group of elephants are standing in the backyard of a house in the morning. Sometimes deer come and call. Sometimes the king cobra stands in the house with its hood up [15]. The rivers and its surrounding areas are interesting in the Terai and Dooars areas of North Bengal.

10.5 Teesta Project River management leads to social upliftment of the people living in the river basin, a prime example of which is the Teesta project. Scientific management of Teesta River has brought economic and social development in and around the Teesta basin. The main objectives of the Teesta project were to provide irrigation water for agriculture, generate hydropower, control floods and create a waterway connecting the Brahmaputra and the Ganges. With the implementation of this project, it is becoming possible

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to provide water for cultivation through irrigation in 6 districts of North Bengal— Cooch Behar, Darjeeling, Jalpaiguri, Uttar Dinajpur, Dakshin Dinajpur, and Malda. From the Teesta Barrage project, 90,000 hectares of boro rice cultivation is possible every year during the dry season alone and produces about 5.5 lakh tons of additional paddy with a market value of at least 30 crore rupees. At least 1 crore 10 lakh labour days are commemorated during the non-working hours of the farmers. Teesta Barrage has ensured growth of kharif crops through irrigation of 9 lakh 22 thousand hectares of land. Simultaneously the construction of the Teesta Canal Road has reduced the distance from Kolkata to North Bengal by 70 km, saving on travel costs and fuel. Also, the travel time is reduced. Teesta Barrage Project provides public drinking water under Siliguri Municipality. Through the flushing system, it is possible to remove the unsanitary environment of the Karala River in Jalpaiguri town. About 650 MW (megawatts) of hydropower is generated from this project and 67.5 MW (megawatts) of electricity are generated every year through hydropower projects from the Teesta Canal alone, meeting domestic and industrial needs (Fig. 10.2). The direct value of which is 50 crore rupees, and the indirect value is many times more. In addition to water for irrigation, power generation, etc., in the application of science, the rivers of North Bengal have their own natural resources and that is fish, the silver crop of river water [17]. In the rivers of North Bengal there are some fish which are generally not found in any other river. These rare fish species in the rivers of North Bengal continue to carry the traditional heritage of North Bengal even today.

Fig. 10.2 The newly constructed Teesta Canal now functioning at Gajoldoba in Jalpaiguri district

10.6 Traditional River Fishes

149

10.6 Traditional River Fishes For a surveyor searching for the local tradition and history there can be no accounting for tastes, but here the taste matters, the delicious—looking Raikar fishes are, however, simply nice to the taste. Happy are those who know the taste of Raikhar fish of Atrai River of Dakshin Dinajpur. The curry tastes of Raikhar fish is really delicious. Raikhar, available only in the waters of Atrai (Atreyee) River, is a renowned and branded local fish of Dakshin Dinajpur district. The local fish diversity of Uttar Dinajpur particularly at Raiganj, the district headquarters, is richer than its counterpart in comparison to Raikhar, the only representative of local fishes of Dakshin Dinajpur. At Raiganj, the fish-sellers in the marketplace adjacent to the Raiganj rail station carry and display a variety of local fish for sale of their catches in the morning. Some fish sellers in the fish market identified the local fishes such as Piyali, Bou, Chapla, Ghaaira etc. The rivers like Kulik and Nagar are the habitat of these Piyali, Bou, Chapla and Ghaaira, indigenous and traditional local fishes of Uttar Dinajpur district. The British officials too recorded the name of Raiganj as one of the large fishing villages of unpartitioned Dinajpur district [16]. Boroli, a local fish of Cooch Behar district, is so popular that the district administration used to arrange an entire festival, where a delicious dish of Boroli is the central part of attraction to each and every visitor of the festival, though it is costly. The Boroli fish festival comes every year with a festive mood which is generally inaugurated by the North Bengal Development Minister of the Government of West Bengal. Boroli fish are abundantly occurring in the mainstream of Torsa River and all of its branches like Buri Torsa, Shil Torsa, Mara Torsa, and Char Torsa. Apart from Boroli, Korti fish is another variety that represents the local fishes of the Cooch Behar district. Boroli, or Korti fishes are available in the district, though fishermen or fishing communities are scarce in this district even in the era of the British period. The number of local fish in the Darjeeling district is quite different from the remaining districts of North Bengal. Darjeeling, the major area of which stood on the hill region with the slope, is a district dearth of local fish and fishing, and surprisingly nobody takes the leadership on surveys for fishing expeditions. In the perspective of fish, fishing, fisheries or fishing communities, the district is neither fish, flesh, nor good red herring, engaged in managing other fish to fry. Local fishes of Malda district are very delicious, and this will be experienced during an occasion or local festival. Any traveler or tourist might experience the taste of delicious curry of Golsa, a Tangra type fish. The habitat of Golsa is the river waters of Punarbhaba and Tangan that flow in and around the Malda district. Malda district is a place of huge fish diversity and availability due to abundant occurrence of fishes in the Ganga River, and therefore it is the only district having several fishing communities who live by fishing [16]. Malda district is not only self-sufficient in fish production, particularly by its capture of fish from the river waters of the Ganga, Mahananda, Kalindi, Punarbhaba and Tangan, but the fishes caught in this district have been transported to the other districts.

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Fish in the district of Jalpaiguri are not only tasty, but everyone recalls its sweetness of variety. Topographically, Jalpaiguri district is befitted for the habitat of such diversity of local fishes. Lines of well-known rivers flowing parallel in the district of Jalpaiguri are the habitat of local fishes with typical names like Bhangna, Khatti, Bhatti, Garali, Boroli, Elang, Tatkini, Rayek, Batasi, Dwarika, Kurail, Bhol, Panya, Mauya, Bangach, Sangach etc. though there are no fish market or depo to transport from this district to the other places. Therefore, nearly all fishing families cultivate land also, the produce of which affords them the main means of support.

10.7 Water Quality Index The water quality index (WQI) reflects the water quality rating of the river water that ultimately indicates the polluted portion of a particular river stretch along the river course [19]. Water quality indices are very important for the determination of river pollution. For North Bengal rivers, the water quality indices are computed based on the data available in the report of West Bengal Pollution Control Board [1]. Water quality indices reflect the water quality rating of a river. Further, a river is said to be polluted based on the permissible limit of BOD concentration in terms of the standards values prescribed by the Central Pollution Control Board [1–3, 20]. On the basis of the BOD data supplied recently by the West Bengal Pollution Control Board to the Central Pollution Control Board, the CPCB has removed some river stretches of Kaljani and Karola from the list of polluted rivers due to good water quality [3]. The water quality of Teesta, Karola, and Kaljani rivers is 100% in good condition but the water quality of Mahananda at the downstream stretch of Ramghat area is quite poor. At Ramghat area, surface water condition at downstream stretch of Mahananda River, is 50% good, 16% fair and 34% poor as per water quality rating based on computed values of water quality indices (Table 10.1). High TDS, TFS and TSS values of Mahananda at Siliguri generally do not affect the water quality rating of the river [4–6]. Such high values of physicochemical parameters are probably due to the huge runoffs of waste materials dumped on the banks of Mahananda nearby Siliguri into the river water causes maximum TDS concentration of 382 mg/l, TFS 288 mg/l, and TSS 468 mg/l for a huge rainfall during monsoon. The huge concentrations of TDS, TFS and TSS do not hamper the water quality and these physicochemical parameters never affect the BOD values of the surface water samples of Mahananda River [8, 11]. The BOD value of Mahananda River ranges from 1.4 to 2.4 mg/l during monsoon period which is within the permissible limit that prescribes that the river water of some stretches of Mahananda is suitable for outdoor bathing. The water quality indices also indicate the river waters remain in good condition. During the pre-monsoon period, the maximum value of TSS goes to 198 mg/l though it does not hamper the values of TDS, TFS and conductivity. Despite total dissolved solids (TDS) and conductivity have a direct linear relationship, but that relationships are not maintained for the river water sample of Teesta collected during the monsoon period where TFS

10.8 Summary

151

Table 10.1 Water quality indices of the surface water samples of the rivers of North Bengal Name of the rivers

Sampling stations

Kaljani

Monsoon

Min

Max

Min

Post-monsoon

2013–14 39.59 (Good)

38.75 (Good)

27.58 48.14 (Good) (Fair)

2014–15 32.71 (Good)

Max

40.35 (Good)

30.8 (Good)

41.51 (Good)

25.21 45.89 34.49 (Good) (Good) (Good)

32.72 (Good)

2013–14 42.9 (Good)

86.79 (Poor)

28.53 63.28 (Good) (Poor)

31.23 (Good)

51.79 (Fair)

2014–15 34.73 (Good)

69.84 (Poor)

26.35 46.87 (Good) (Fair)

45.13 (Good)

66.51 (Poor)

2013–14 21.12 (Good)

25.45 (Good)

16.42 74.1 (Good) (Poor)

21.93 (Good)

22.63 (Good)

2014–15 19.5 (Good)

29.93 (Good)

17.29 31.1 21.5 (Good) (Good) (Good)

24.99 (Good)

2013–14 29.13 (Good)

27.58 (Good)

16.33 21.69 23.43 (Good) (Good) (Good)

26.22 (Good)

2014–15 34.04 (Good)

36.95 (Good)

18.11 21.58 28.14 (Good) (Good) (Good)

30.37 (Good)

Alipurduar 2013–14 36.38 (Good)

33.53 (Good)

26.18 193.52 (Good) (Poor)

30.49 (Good)

32.41 (Good)

2014–15 39.22 (Good)

33.81 (Good)

28.32 32.26 34.72 (Good) (Good) (Good)

33.28 (Good)

Ramghat

Karola

Pre-monsoon

Min

Mahananda Siliguri

Teesta

Year

Siliguri

Jalpaiguri

Max

Water Quality Rating: WQI: 0–45 = Good; 45–60 = Fair; > 60 = Poor

and TSS values are 802 and 878 mg/l respectively on comparison to the maximum conductivity value of only 71 µs/cm of the water samples of monsoon period [10]. The exceptional value of 2402 mg/l for TFS is probably due to huge runoffs of waste materials dumped on the bank around the municipal discharge point of Alipurduar because of heavy rainfall during the monsoon.

10.8 Summary Acute land erosion, submergence of agricultural land, tea plantations, rural and suburban areas are major problems of the rivers in North Bengal. Floods due to overflowing of banks in populated areas and sand accumulation in agricultural areas, river expansion, upwelling of riverbeds, and accretion of large amounts of silt and gravel cause rivers to leave their old courses through separation from the main river and create new channel or river courses. In addition, large-scale displacements of important communication systems such as roads and railways pose a problem. Human habitation and its continuous growth along the banks of the river obstruct the natural

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course of the river and force it to change its course. Moreover, various other manmade obstacles obstruct the course of the river [7]. The concerned department of the state government tries to maintain the course of the fast-flowing river by constructing armoured dams, earth dams, revetments, spurs, porcupines etc. In addition, various departments work to reduce the intensity of floods in villages and towns, reduce soil erosion and accelerate the task of irrigation of agricultural land through various small projects. Every year the flood forecast of the rivers of North Bengal is prepared by the departmental control room after being complied with the rainfall prediction in the weather bulletin published daily by the India Meteorological Department (IMD).

References 1. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal 2. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 3. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi 110032, p 94 4. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 5. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 6. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 7. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 8. Das GK, Datta S, Sanyal SK (2004) Need for geomorphic mapping in terms of physico-chemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 9. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 10. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9 11. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 12. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN 978-3-319-11342-5 13. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN 978-3-319-44190-0 14. Das GK (2020) Forest covers of West Bengal: a district-wise review. Reason Tech J XIX:26–63. https://doi.org/10.21843/reas/2020/26-63/209272 15. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1

References

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16. Das GK (2021) Localities known by local fishes in North Bengal. Frontier 17. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 18. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6 19. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. License: CC BY 3.0 IGO. http://hdl.handle.net/10986/33224 20. Ewing GN (1985) Instrumental method of chemical analysis. McGraw Hill Book Company, New York, p 624. ISBN 978-0070198517

Chapter 11

Bidyadhari—A Sewage-Fed Tidal River

Abstract Small streamlets like Nona Gung, Noai, Sunti and Yamuna rivers form the river systems of Bidyadhari. Originating from the district of Nadia and outfalls in the Jhilla River of the Sunderbans, Bidyadhari has been carrying wastewater effluent of the megacity Kolkata since the British period by which the river got polluted all along its tidal stretch from Haroa upstream to Malancha Downstream. The point sources of mixing of domestic wastewater and industrial effluent from Kolkata metropolis are the places of union of canals. The concentrations of determinants of declined water quality like dissolved oxygen of the river water are very low and even sometimes are below detectable limit. The water quality rating in the context of the values of computed water quality indices is extremely low in conditions that indicate its extremely poor usability in all aspects for agriculture, aquaculture and domestic uses. Keywords Bidyadhari · Sakha Bidyadhari · Adi Ganga · Piyali · Water quality · River environments

11.1 Bidyadhari River Course Bidyadhari is a very important river in undivided twenty-four parganas. Its current source is Barga Bill in Nadia district. From the Barga Bill it flows over the North 24 Parganas and joins the Kalindi-Raimangal River in the Sundarbans. Long before the Yamuna flows east of Triveni from the Hooghly River, the Bidyadhari was the only course of the lower Ganga basin. In Rennel’s map of 1781, a stream of Bidyadhari flows through Kashinathpur, Mahesh Pukuria, Pratapnagar, Tardah, Dhapabil Baor in the northern part of the Matla River in the Canning of the present South 24 Parganas towards Shyambazar in Kolkata. The famous Tardah of Garia was once an important port. The first settlement of the Portuguese in the twenty-four parganas was also built in this port. The tile drain of the rush is also mixed in this Bidyadhari. After the closure of Yamuna’s headwaters, Haringhata’s Barga Bill is now regarded as the source of Bidyadhari. However, it cannot be accepted that Bidyadhari was a tributary

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_11

155

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11 Bidyadhari—A Sewage-Fed Tidal River

of Yamuna from early times. Because Yamuna cannot be called an ancient river by any means. According to archeologists, civilizations as ancient as Mohenjo-Daro and Harappa can be found in the adjacent areas of Bidyadhari river basin in West Bengal. Artifacts of different periods have been found in Berachampa, Chandraketugarh, Hadipur, Minakha etc. of North 24 Parganas which helped a lot to know about the past. According to some historians, between 300 BC and 500 AD, international trade revolved around this region. Chandraketugarh of Berachampa had the Gangaridi port of international fame. According to archaeologists, the civilizations of Haroa and Chandraketugarh date back to the pre-Harappan period. Dwiganga or Deganga village in Barasat subdivision is also known as a very ancient place. Its age can be guessed by looking at the brick ruins and large ponds. Historians see this Deganga as the existence of civilization developed on the banks of Bidyadhari. Many also speculate that the Bidyadhari was once a branch of the Bhagirathi which, when it began to meander, created a new flow as the slope of the land towards the south-east. This flow is known today as the Yamuna River. Bhagirathi lost its grandeur only after the origin of this Yamuna. It gradually narrowed down to where it stands today. It is believed that the current condition of Bidyadhari also happened due to the same reason. Time is a very strange indicator of change. Once the appreciation is at its peak, that appreciation is slowly lost with the evolution of time. Not only humans, but also nature is not spared from this change. A once strong flowing river becomes a canal when it gradually loses its speed by forming a natural delta. About two thousand years ago, people came to know about the great Bidyadhari River described by the Greek geographer Ptolemy. That river is today the Guma Canal of Ashoknagar in North 24 Parganas. Even this canal was once the Dwiganga or the second Ganga i.e., Deganga. The amount of natural gas and oil that has been discovered under the Guma Canal clearly suggests that this entire area was occupied by the Bay of Bengal. The estuary of the Ganga was near the Rajmahal Hill. Then the river formed this flat expanse as it completed its delta formation. Moreover, Bidyadhari is highly polluted for carrying the sewerage of Kolkata for more than two centuries. Since then, the water of this river is no longer usable. The environment on both sides of the Bidyadhari River, which carries polluted sewage water, is gradually becoming uninhabitable. Assessment of such environmental deterioration as well as computation of water quality indices will be helpful to monitor water pollution level of Bidyadhari River.

11.2 Bidyadhari River Systems Bidyadhari River originates from Nagarukhra in Nadia district. The name of Bidyadhari River in the source area is Nona Gung. After entering North 24 Parganas district from Nadia district, it is named Bidyadhari after its union with the combined flow of Noai and Sunti rivers (Fig. 11.1). Noai and Sunti are very small rivers in context with their length and width. The present condition of Nona Gung, Noai or Sunti

11.2 Bidyadhari River Systems

157

Fig. 11.1 Bidyadhari River near its source of origin at Ashoknagar in North 24 Parganas district

River is like a narrow canal. Yamuna River was the freshwater source of Bidyadhari River at its source. But the river Yamuna is now dying, when it is filled with rainwater, Yamuna appears to be a river. Bidyadadhari is known by different local names throughout the river course viz. Haroa Gung, Kulti Gung, Choumuha Gung, Malancha River, and Kalagachia River from its upstream to downstream. Bidyadhari later is divided into two different streams Jheela and Raimangal in the Sunderbans [17, 20]. Bidyadhari consists of several tributaries. Most of these tributaries are now extinct and dying, some traces of which can still be seen across the paleochannel of the river.

11.2.1 Sakha Bidyadhari Another Bidyadhari river existed. The name of this Bidyadhari River is Shaka Bidyadhari and it was connected upstream with the main Bidyadhari River. It was joined by the Beliaghata Canal and Tolly Nullah after a short distance of about 55 km and was connected to the Karati and Amjhara rivers in the Port Canning area. The combined streams later became a big river and known as the Matla River from Port Canning. The source of the Matla River is Sakha Bidyadhari, which is now completely extinct. Sakha Bidyadhari with water from several canals once flowed from Sealdah in old Calcutta to Matla of Port Canning. The Karati or Kuribhanga River flows from the

158

11 Bidyadhari—A Sewage-Fed Tidal River

Poyna Abad and Sarengar Abad in the north along with the Amjhara or Bichuti canal flowing on the eastern side that joins Sakha Bidyadhari River to form the source of Matla River near Port Canning. Tolly nullah and Beleghata canal once discharged into this Sakha Bidyadhari and the river Matla received the entire quantum of discharge at its source. The earlier name of Canning town was Matla. The river was named Matla probably because it flows through the areas of the Sunderbans named Matla. After flowing southward for about 1 km, the Matla merges into the Bay of Bengal. The Matla River, which flows to the sea and is navigable by river steamers up to Port Canning [16, 21].

11.2.2 Piyali Piyali River has started flowing from the Sakha Bidyadhari River near Pratapnagar of South 24 Parganas. After flowing south for about 45 km, it joins the Matla River. A pumping station has been set up under the supervision of the Irrigation Department of the Government of West Bengal at Uttarbhag Ghat in the upper reaches of the Piyali River. As a result, the excess water accumulated during the monsoons of the Garia, Sonarpur, Subhasgram, Mallikpur, and Baruipur regions is pumped through the Piyali River into the Matla River. In the eighties of the last century, the mouth of the Piyali River was dammed at Ambikanagar. The dammed riverbed has provided irrigation facilities to local farmers by harvesting rainwater. The once Piyali River with salty tidewater now carries fresh water. But Piyali has lost its momentum for damming the mouth of the river. As there is no tide in the river, numerous long seaweeds obstruct the movement of both fishing and mechanized boats. Now no mangroves can be seen along the floodplains of Piyali River. The river is invisible in the events of breaking and building. Tidal shoals do not wake up. Now Piyali is a river only by name, not by characteristics and features [11].

11.2.3 Adi Ganga At one time the river Adi Ganga was well-connected with the river Bidyadhari through which goods were transported from the then Calcutta, the capital of British India to other parts of lower reaches of undivided Bengal particularly in Khulna and Barisal (presently in Bangladesh). Now the river Adi Ganga is like a pond somewhere else or exists like a lake or a narrow canal. Major Tolly dredged Adi Ganga about two centuries back, but the existence of that Adi Ganga is highly 4 to 5 km or less at present in the Kolkata metropolis. Adi Ganga’s presence outside the city, however, is a little different. A tiny turtle, basking in the mud slope, slithers to the water, a gallinule sneaks in the fig bushes, a heron in its knee-dip water cranes its neck in searching of a swimming fish—these are the scenario of Adi Ganga at a glance adjacent to the Krishnamohan

11.3 Riverside Vegetation of Adi Ganga

159

station of Sealdah-Lakshmikantapur railways. Adi Ganga, a sick river, still exists here as wetlands with an extension of about two kilometers stretch in and around the Baruipur Municipality. The relic of this river is still seen as patches here and there, in the shape of a pond after excavation either by the then zamindars or by the locals in order to maintain religious rituals in the holy waters of Adi Ganga, though they are rainwater accumulated ponds in Mathurapur, Dakshin Barasat and Joynagar areas. Adi Ganga River has long fallen into decay due to lack of head water supply from the river Hooghly. Major William Tolly, an officer of British East India Company, took initiatives for renovation of a part of Adi Ganga. As this part was excavated and deepened by Major William Tolly in 1773 and connected to river Bidyadhari at Samukpota helping easy transport of goods from Kolkata to Khulna and Barisal, so therefore and thereafter, this part of Adi Ganga bore his name and known as Tolly’s Nullah. Adi Ganga was once the main flow of the Hooghly River from the fifteenth to seventeenth century but has subsequently dried up which is also known as Tolly’s Nullah, Surman’s creek and Gobindapur creek in and around Kolkata metropolis. The Adi Ganga is a river of historical interest for Chaitanya Dev’s Nilachal visit and for the uses of Adi Ganga waterways by Dhanpati Saudagar, Srimanta Saudagar and Chand Saudagar as mentioned in the Chandimangal and Manasamangal respectively.

11.3 Riverside Vegetation of Adi Ganga Adi Ganga River, at present, of about two kilometers stretch, in and around the Baruipur Municipality, is a stagnant water body, filled only with the rainwater which is static fresh water covered with weeds and marshes, having the depth of water on an average 6 feet in summertime and 16–18 feet during monsoon season. The riverturned wetland is characterized by herbaceous vegetation, receives drainage from the Baruipur Municipal areas and becomes a shallow marshy wetland [18]. Water moves from this wetland down into an underground aquifer recharging groundwater table round the year. The groundwater is usually cleaner, due to filtering processes, than it is on the surface. Thus, plenty of ground water is available for agricultural purposes and for human uses in the area. Further, the Adi Ganga wetland retains nutrients, most importantly nitrogen, phosphorus and potassium by accumulation of subsoil. This wetland is said to act as sources as the nutrients are returned to the surroundings and that is why Baruipur area is well known for its greenery and orchards for soil fertility particularly due to Adi Ganga. It contains potential energy for humus consumption, normally in the form of plant matter and peat. Local farmers usually make compost, a kind of bio-fertilizer, after collecting plenty of water hyacinths floating in the Adi Ganga waters and leaving under the soil for decomposition. Surprisingly, no migratory birds visit this wetland region during winter season, although the diversity of fish species is notable. Adi Ganga is also important as a genetic reservoir for certain species of plants, particularly the weeds and herbs, commonly known as wetlands plants (Table 11.1). The Adi Ganga wetland supports a dense population

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11 Bidyadhari—A Sewage-Fed Tidal River

Table 11.1 Wetland plants, phytoplankton, and zooplanktons from the wetland environments of Adi Ganga Wetland plants

Phytoplanktons

Zooplanktons

Sapla—Nymphaea nouchali Kalmi sak—Ipomoea aquatica Kachuripana—Eichhornia crassipes Kachu—Colocasia esculenta Bera Kalmi—Ipomoea carnea Topa pana—Pistia stratiotes Chesco, Fatfati—Scirpus sp. Sarbajaya, Kalaful—Canna sp. Hasnahena—Cestrum diurnum Lal pana, Duckweed—Lemna sp. Mator dal pana, Duckweed—Spirodela polyrhiza Suji pana—Wolphea sp. Indur kan pana—Salvinea sp. Jhanji—Hydrilla sp. Pata Sapla—Oetelia sp. Pata Jhanji—Vallisneria sp. Dumur—Ficus hispida

Nostoc sp. Anabaena sp. Microcystis sp. Anabaenopsis sp. Spirulina sp. Chlamydomonas sp. Volvox sp. Pandorina sp. Eudorina sp. Scenedesmus sp. Pediastrum sp. Chlorella sp. Cosmarium sp. Euglena sp. Peridinium sp. Navicula sp. Nitzschia sp.

Filirica Brachionus Keratella Nauplius Cyclops Mysis Copepods

of phytoplankton and zooplankton that fishes and other herbivorous aquatic animals feed on such nutrient-rich microflora and fauna. The Adi Ganga wetland has significant impacts on hydrology of the surrounding areas. Its hydrology leads to a unique vegetation composition that can enhance species richness. Nutrient cycling and nutrient availability are both significantly influenced by hydrologic conditions. The field of Adi Ganga wetland is not yet routinely studied, that is to be properly combined in university academic programmes as there is great deal of interest in formulating sound policy for the regulation and management of such a wetland. These regulations and management approaches need a strong scientific underpinning integrated as wetland ecology. After all, the efforts of Baruipur municipality will not perish in the dust, they maintain a large sized park at the bank of Adi Ganga along with a picnic spot, though their performance leaves much to be desired. The Adi Ganga wetland, in its sphere, is all about the glow to keep it going.

11.4 Drainage Canals The sewage, wastewater, and drainage water from the Kolkata megacity and suburbs are drained into Bidyadhari River by a number of canals, channels, and waterways. The drainage water overflowing the city due to heavy rainfall during monsoon are either drained by gravity flow or pumped into various canals that ultimately outfalls into Bidyadhari River. Among such canals, Bagjola Khal, Kestopur-Bhangarkata Khal, and Beliaghata Circular Canal, are important for sewage and wastewater

11.5 River Environment and Water Quality

161

discharge from the megacity Kolkata. Wastewater from Kolkata drains into Bidyadhari River near Kulti area where Bidyadhari River is known as Kulti Gung. Apart from these canals, Storm Weather Flow Channel (SWFC) and Dry Weather Flow Channel (DWFC) play a significant role during awkward situations like occurrences of cyclonic storms etc. Most of these canals are silted up for carrying heavy drainage load from the megacity and suburban areas. The reason behind the heavily silted up situation is nothing but unplanned rapid urbanization of the lowland areas in the city outskirts and suburbs lying vacant even four decades ago [12]. Besides, the canal banks and sometimes canal sections are encroached by the outsiders that clogged the smooth passage of water. There have been large cattle sheds in the old city for centuries that drain total garbage into the canals that are used for the flow of wastewater [13]. Sometimes railway crossings, and existing shortcuts are advantageous for persons in walking and cars cause obstructions reducing the adequate passage in the flow of waters mixed with wastes and sewage from the megacity of Kolkata. Untreated industrial effluents, household garbage, sewars etc., thrown directly into the canals creating heavy siltation resulting in water logging in many areas in the megacity by overflooding that caused inconvenience to the residents. Such heavily silted up canals changing into almost stagnant water bodies create not only health hazards like vector borne diseases but also livelihood of the people by the side of those canals [15]. In the present years, vector borne diseases like dengue account for high mortality rates in the urban belt and suburbs of the megacity. Increasing of hydraulic capacity through dredging and re-section of the canals are the only ways to keep up better environmentally including health and roads of the locality by smooth drainage of wastewater along with rainwater to Kulti Gung i.e., Bidyadhari River. Apart from dredging, removal of encroachers and large cattle sheds from the canal banks may stop the discharge of effluents into the canal waters.

11.5 River Environment and Water Quality The main flow of the Bidyadhari River is in the Sunderbans region. As there is no industrialization in the Sunderbans region so the level of pollution here by industrial effluent is relatively low [7]. One of the major causes of river water pollution in the Sunderbans is the sediments that move during ebb and flood tide. The rivers of Sundarbans have lost their momentum due to the excess of silt and the formation of numerous tidal bars, point bars, and mid channel bars. Also, the rivers of Sundarbans are getting polluted due to various other reasons. Pollution affects the biota and organisms living in the river [5]. Migratory fish and birds are increasingly forced to change their nest-making abode during monsoon and winter respectively. Sewage from various canals of Kolkata Municipal Corporation flows into the Bidyadhari River and is the main cause of river pollution [4, 6, 9]. As a result, during high tide, the sewage water rises up to Haroa in the upper course of Bidyadhari and flows in the lower course to Dhamakhali during low tide. Solid metals in free sewage effluents from industrial areas of East Kolkata are mixed with Bidyadhari

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11 Bidyadhari—A Sewage-Fed Tidal River

water through various sewage canals and thereby largely increase the concentrations of total dissolved solids (TDS) and total fixed solids (TFS). These solid metals (chromium, cadmium, zinc, lead, iron, copper, manganese etc.) are generally insoluble in river water that enhance the value of electrical conductivity (EC) and total hardness [9, 14]. All those metals are accumulated in cells and tissues of the plant or animal body through uptake of food or various processes and are carried unchanged by the next consumer. The movement of such chemical substances absorbed into the various layers of the food intake is called biomagnification. In this way, people consume polluted river fish as food and assimilate various metals into the cells and tissues of the body. As a result, the possibility of incurable cancer may arise in the future [4, 5, 9]. All these metal substances are consumed by different species of phytoplankton and zooplankton, besides snails and clams of the phylum Mollusca [24]. Also specially adapted mangroves play a special role in preventing metal pollution for their physiological functions [3]. Sewage and garbage from the city of Kolkata and free effluents from the industrial areas of East Kolkata enter the Bidyadhari River through several drains and canals. Bidyadhari flows east of Calcutta megacity and Bidyadhari is the only river that carries wastewater and sewage to Sunderbans from the industrial areas of East Kolkata. For these reasons, the water quality index of its upstream stretch at Haroa and at Malancha downstream of Bidyadhari River shows exceptionally higher values indicating water quality rating of the river water in extremely poor conditions (Fig. 11.2 and Table 11.2). Water quality rating is determined by the values of water quality indices computed after the analytical data of physicochemical parameters of the surface water samples [1, 2, 23, 25, 26]. Other reasons for which the water of the rivers of Sunderbans become polluted are collision or sinking of the oil tankers; oil spillage from ships; cleaning the tanks of oil tankers in rivers; spillage of oil in the waters of rivers or estuaries from large ships to small ships during transfer of oil; indiscriminate use of pesticides in agriculture and its leaching into river water etc. [8, 10].

11.6 Natural Remedy Some mangrove species like Chak Keora, Garjan etc. can absorb waste-borne metals that causes biomagnification. The tissues and cells of these mangrove species showed less than 1 percent metal contamination whereas the surrounding soils contained 99 percent manganese and 100 percent iron, chromium, lead, zinc and cadmium. Possible reasons for such low pollution by the toxic metal substances in the tissues and cells of mangroves are—(i) mangroves can absorb capillary water by expelling metals during ascent of sap i.e., the root system of mangroves can be said to be the main barrier to metal pollution and (ii) if little metallic substances are absorbed, the mangroves’ adaptive physiology prevents the accumulation of those metals in the body [22].

11.7 River Commons

163

Fig. 11.2 Bidyadhari River at its downstream stretch near Malancha of North 24 Parganas. Note the series of brick kiln along the riverside areas of Bidyadhari

Table 11.2 Water quality index (WQI) of the surface water samples of Bidyadhari River Water quality index (WQI) of Bidyadhari River Sampling station Haroa Malancha

Year

Premonsoon

Monsoon

Min

Min

Max

2013–14

260.16

2014–15

307.78

2013–14

811.13

2062.4

2014–15

632.07

1980.7

Postmonsoon Max

Min

Max

514.45

76.53

270.82

88.82

106.75

739.32

200.38

507.61

273.84

310.79

100.61

665.5

66.77

228.73

242.87

1558.3

267.24

481.9

11.7 River Commons Most of the area through which the Bidyadhari River flows belongs to the Sundarbans. The reason why there are no forests in this part of the Sundarbans is because during the British period, the forests were cleared from this area to make way for human settlements and agricultural land. Tribal people brought from Bihar and Jharkhand cleared the forest on both sides of the river but after the creation of the land, the people of Midnapur, people who migrated from the other side of East Bengal, and Muslim community occupied the land. Most of those tribal people who lost their

164

11 Bidyadhari—A Sewage-Fed Tidal River

lives while clearing the forests of Sundarbans remained peddling Sundarbans as no one cared about them. Since then, they have lived in remote areas of villages on both banks of Bidyadhari River although recently all communities live together in Sunderbans area. This diverse human coexistence is found along almost all rivers in the reclaimed areas of the Sundarbans that can be called ethnological diversity.

11.8 Ethnological Diversity in Sunderbans Sunderbans presents ethnologically the aspect of international borderline areas of the part of two districts—North and South 24 Parganas. Most of the inhabitants are outsiders having their routes either in the adjacent Midnapur district or from the districts of Satkhira, Khulna and Bagerhat of the newly emerged nation Bangladesh that show a high immigration which attracts reclamation land of almost free of cost and it is mostly of a permanent character. At present, in general, the entire population of the Sunderbans may be classified into four divisions—Midnapuria, Bangal (East Bengalees), Mohammedan and tribal communities. In this respect Sunderbans suggests points of resemblance to the unity of diversity through different culture, customs, rituals and long-established practices, though the people in general, considered as living in relationship and fellowship in the society despite the co-existence of the rich and poor in the same hamlet. Ethnologically, among the Midnapuria and Bangal, the settlement of sacerdotal class of Hindus like Brahmins has not taken place in the areas of the Sunderbans since its reclamation, but of late they are settled performing priesthood in the villages, many of them are also landholders, and others are employed in Government jobs particularly in the primary and secondary schools. Many also of these Brahmins, either landholders or employed as teachers or secretaries of the Gram Panchayats, act as priests and religious instructors to the lower castes. Kayastha, the writer caste of Bengal, are rarely visible, though a few are immigrated for employment in schools recommended by the School Service Commission. In majority, Poundra Khatriya or Pod community is numerous in numbers, followed by Mahisya, Namasudra, Bagdi, Mahara, Baule, Moule and Jele. The Pod community, large in numbers, scattered all over the areas of the Sunderbans, is classified into four sub-castes based on their occupations by L. S. S. O’Malley in his Bengal District Gazetteers, 24 Parganas, 1914—More than half the Pods of Bengal are residents of the 24 Parganas, practically all the remainder being found in adjoining district, viz, Khulna, Midnapore, Howrah, Jessore and Hooghly. There are four main sub-castes, viz. Chasi Pod, Mecho Pod, Tanti Pod and Bhasa Pod or Dhamna Pod. The differentiation between them appears to have had its origin in differences of occupation, as indeed may be gathered from the names…the Bhasa Pods appears to be a comparatively recent accretion from outside. The name Bhasa means floating, and tradition has it that the Bhasa were washed over to the 24 Parganas from Hijili and other places in Midnapore in the cyclones of 1824 and 1834 [19]. Further, Annu Jalais tells a tale on the naming of Pod community in her book, Tiger of Forest, 2009 hearing the story from a person

11.9 Tribal Recreations

165

belonging to the same community—Parasuram needed people to come and fight on his side, we got so scared that we crouched, hiding our faces in the upturned earth of our ploughed fields and sticking our buttocks up in the air. When Parasuram saw this, he said, why, these are not people, they’re just bums? Since then, we’ve been stuck with our names, and we don’t really fancy it [19]. The rest is the tribal community, and they are brought from the different areas of Bihar for the reclamation purpose of the Sunderbans with a hope of distributing them reclaimed land free of cost for a lifetime during the British era and they have not frittered away such opportunity. Mohammedans of the Sunderbans are generally converted Muslims from the lower caste Hindus in order to escape or supposed to be greatly relieved from the torture and tyranny of the upper caste Hindus. These lower caste people lived early in the districts of Satkhira, Khulna and Bagerhat of Bangladesh and presently in the Indian part of Sunderbans after their gradual immigration with time. These people of the Sunderbans, irrespective of their caste and communities, stand united to perform social and cultural activities like fairs for religious ceremonies in the villages where minor articles, brass ware, utensils, furniture, toys and various eatables are sold in the fairground. Even they establish marketplaces in the villages according to their necessity. Further, Sunderbans is peculiarly liable to be infested by banditti off and on who ravage the land, forest and water courses in armed bands numbering several hundred particularly in the border areas of the Bangladesh Sunderbans. Apart from such minor irregularities, the people of the Sunderbans are simple minded personality; they respect them who know how to do the same. They are very friendly, emotional and mixed practical.

11.9 Tribal Recreations Tribes have been living in some villages on the left bank of Bidyadhari River particularly in the Sandeshkhali 1 & 2 Blocks since the reclamation of the Sunderbans. The tribes mainly helped to reclaim the mangroves forest only for a piece of reclaimed land for farming as their wage. Since then, tribal communities have lived in a few villages on the left bank of the Bidyadhari River. On the day of sitting the market, they enjoy playing with the cocks reared in their family during November to March. The play, known as cock fight, is purely a kind of tribal recreation. It is a soft haze dewy season afternoon. A mild gathering of hardly a hundred people around a circle-shaped spot is seen at the roadside of a market in Sandeshkhali block, about one km away from the Dhamakhali ferry ghat. All the spectators of the gathering are silent and serious, even they are not ridiculing, jesting, or bantering, only keeping vigil as the event proceeds at the center of the tiny playground where two cocks are attacking each other. These cocks are called as the striker and their owners induce their strikers shouting off and on for a straight win of the game. The cocks are accompanied with a sharp tiny knife tightly tied with their legs. The cockfight is a competitive one, rather than merely a game in the playground as the cock, the defeated one, must have to be killed with several attacks by its rival, and

166

11 Bidyadhari—A Sewage-Fed Tidal River

only then the surviving one is to be declared winner though severe wounds are borne around its body. The owner of the winning cock leaves the playground after being prized with the defeated and dead cock as his winning trophy. In Sunderbans, only the tribal community take part in such an event of cockfight, and thus, cockfight is a tribal game of tribal affairs. Cockfight is commenced on and from the Kojagori Purnima (the day of worshiping Goddess Lakshmi) and ends on the day of Chaitra Sankranti (the last day of Bengali Year). The performance of the game has been continuing and is extended almost six months. Again, it commenced from the day of next Kojagori Purnima in the ensuing year. The schedule of cockfighting is simply connected with the leisure period of the tribal Baule (woodcutter), Moule (honey-collector) and Jele (fisherman). Only the tribes could take part in the cock-fighting events, although the spectators of the game might be of heterogeneous origin coming from the different castes of both Hindus and Muslims. There are no hard and fast rules on such categorical participation in cockfight, but it is a traditional game that keeps its flag flying as a tribal event since those very days of reclamation of the Sunderbans. Cockfight is not merely an entertainment of the tribal community of the Sunderbans, but it is an event of the maintenance of their unity indicating they are packed for any kind of gregarious movement at least in the remaining days of the year at their domain. Almost all the terms used in the event of cockfight are of tribal origin. The playground of cockfights is known as Akhrhai. The cocks performing in the cockfights belong to the different varieties and names like Jhijhri, Mala, Junglee, Baga, Kaora, Uchhara etc. The participant cocks are at first allowed to select their own rival outside the playground much before being performed in the real fight inside the Akhrai. Kantidaar, the experienced men, tie the small knife with the leg of a cock by getting ready for fighting. Kaantidaar is waiting outside the Akhrai taking all the necessary items like small knives, leather pieces, needle, threads, cloth pieces etc. The Burhi, an associate to the Kantidaar, assists the Kantidaar in tying knives on the legs of the cock. The knife, to be tied, is known as kant (Kantidaar comes from this term ‘kaant’). The kant (knife) is classified as moza foli, benka foli, soza daant, benki etc. according to their size, shape, and sharpness. A Kantidaar is considered only a little wage of two to four rupees for his performance of knife-tying of a cock. The knife is a poisonous one with the application of tunte (Copper Sulfate) covering round the knife. There is tremendous excitement during the event of cockfight, but generally no spectator shouts. The owner of the winning cock gains that cock already defeated, almost dead or completely dead, as his trophy. The winning cock is known as Jeetkar whereas the defeated cock Paourh. Being in practice, obeying all the prejudices much before arrival to akhrai, all the cock-owners maintain traditional rituals to achieve a good performance of his cock in the event of cockfight. The owner of the cock covers his fighting cock with a cloth on his way to the akhrai, he never talks to anybody else on the road, and never looks back, never responds to anybody beyond him or even does not respond to his nature’s call on the way to the cock-fighting ground. This is a fact that a cock always attacks looking for another one in its surrounding area and it is created by Lord Krishna as per the tribal myths. The myth is like that

References

167

cocks always warned King Kangsha, uncle of Lord Krishna, about all suspicious movements of Lord Krishna for killing Kangsha as the cocks are the followers of the King Kangsha. But the most veteran politician of the epic Mahabharata, Lord Krishna disbanded the unity of the flock of cock by opening the windows of disbelief among the cock’s community, and that is why the cocks fight among them. Despite such disbelief of the cocks among themselves, the tribal community is always united and gregarious. In the past, due to their unity, the tribes took part whole-heartedly in the Tebhaga movement against the State Government and organized the Hool revolt against the European Company rulers in British India.

11.10 Summary Due to Malancha’s proximity to the Bay of Bengal, the level of total dissolved solids is high. For the same reason, the level of total dissolved substances including total dissolved solids and total fixed solids increases as tidal water reaches Haroa. At Kulti, the river water of Bidyadhari has the highest concentrations of sewage and industrial effluents causing the surface water of Malancha to have the highest concentration of total dissolved solids. The level of total suspended solids is lower than that of total dissolved solids in the surface waters of Bidyadhari. This is because the polluted sewage carried by the canal mixes with the river water and settles in the riverbed. However, the level of total suspended solids is high in surface water of Haroa due to unfavourable tidal hydrodynamics. Biochemical oxygen demand in Bidyadhari River water is far below the acceptable level. This is because the canals carry sewage containing a considerable amount of organic matter. All those organic materials are decomposed by microorganisms in the presence of sunlight and available dissolved oxygen in the surface waters of Bidyadhari. As a result, values of biochemical oxygen demand in the surface water of the river increases [3]. Factory effluents from East Kolkata carried by canals mix with river water increasing chemical oxygen demand which was observed in the surface waters of Bidyadhari at Haroa, Kulti, Malancha, and Dhamakhali. Microorganisms break down organic matter in surface water brought into rivers by the canals due to favourable pH levels in river water. Due to these reasons, despite the existence of Bidyadhari River, the water of this river is completely unusable. Kolkata Municipal Corporation and the concerned department of the state government can try to make the water of this river usable so that untreated sewage does not mix with river water.

References 1. Anonymous (2015) Database on environment and forestry statistics of West Bengal. Bureau of Applied Economics and Statistics, Department of Statistics and Programme Implementation, Government of West Bengal

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11 Bidyadhari—A Sewage-Fed Tidal River

2. Anonymous (2020) Action plan for rejuvenation of River Jalangi Krishnagar, West Bengal, priority—IV. Nodal Agency Municipal Engineering Directorate, Department of Urban Development & Municipal Affairs, Government of West Bengal, River Rejuvenation Committee, West Bengal, pp 1–14 3. CPCB Report (2022) Polluted river stretches for restoration of water quality. Water Quality Management (I) Division, Central Pollution Control Board (CPCB), Ministry of Environment, Forests & Climate Change (MoEF & CC), Parivesh Bhawan, East Arjun Nagar, Delhi, 110032, p 94 4. Chattopadhyay B, Datta S, Chatterjee A, Mukhopadhyay SK (2001) The environmental impact of waste chromium of tannery agglomerates in the east Calcutta wetland ecosystem. J Soc Leather Tech Chem 84:94–100 5. Das GK, Datta S (2004) Surface water assessment of Kolkata wetlands. IGA Review, Max Mueller Bhavan, Kolkata, pp 51–54 6. Das GK, Datta S (2004) Studies on the impact of water quality on the adjoining wetland ecosystem of Bidyadhari River, West Bengal. Indian Sci Cruiser 18(4):16–21 7. Das GK, Datta S (2006) Managing waters of wetlands in and around Kolkata. Indian Sci Cruiser 20(3):22–27 8. Das GK, Datta S (2014) Man-made environmental degradation at Sunderbans. Reason XIII:89– 105 9. Das GK, Datta S, Sanyal SK (2004) Need for geomorphic mapping in terms of physico-chemical analysis of the sewage fed Bidyadhari River carrying effluents from the greater Calcutta. J Indian Soc Coast Agric Res 22(1&2):49–51 10. Das GK (2003) Changing environment and responses of the living systems. IGA Review, Max Mueller Bhaban, Kolkata, pp 16–19 11. Das GK (2006) Sunderbans—environment and ecosystem. Sarat Book House, Kolkata, p 254. ISBN 81-87169-72-9 12. Das GK (2011) Impact of salinity and nutrients on the changing mangrove floristic—a case study from the river flood plains of Sunderbans, India (119–129). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 13. Das GK (2011) Studies on the potentiality of medicinal applications of some mangroves of Sunderbans (68–73). In: Biotic potential and the abiotic stress. Lambert Academic Publishing AG & Co., Saarbrucken, Germany, p 408 14. Das GK (2012) Impact of water quality on the changing environmental scenario of Sunderbans. Reason XI:57–66 15. Das GK (2014) Environmental scenario of Sunderbans: planning and management (1–24). In: Anthropecology and applied biodiversity. OmniScriptum GmbH & Co. KG, Saarbrucken, Germany, p 408 16. Das GK (2015) Estuarine morphodynamics of the Sunderbans. Springer, Switzerland, p 211. ISBN 978-3-319-11342-5 17. Das GK (2017) Tidal sedimentation in the Sunderban’s Thakuran Basin. Springer, Switzerland, p 151. ISBN: 978-3-319-44190-0 18. Das GK (2019) Medicinal plants around wetlands in Sunderbans. Frontier 1–3 19. Das GK (2019) Ethnological diversity of Sunderbans. Frontier 24 September 2019 20. Das GK (2020) Forest covers of West Bengal: a district-wise review. Reason Tech J XIX:26–63. https://doi.org/10.21843/reas/2020/26-63/209272 21. Das GK (2020) Declining River Matla. Indian Sci Cruiser 34(5):8 22. Das GK (2021) Forests and forestry of West Bengal—survey and analysis. Springer, p 231. ISBN 978-3-030-80705-4. http://www.springer.com/, https://doi.org/10.1007/978-3-030-807 06-1 23. Das GK (2022) Shilabati River: its environment. Indian Sci Cruiser 36(5):40–45 24. Das GK (2023) Coastal environments of India, a coastal West Bengal perspective. Springer, Switzerland, p 232. ISBN 978-3-031-18845-9. https://link.springer.com/book/10.1007/978-3031-18846-6

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25. Essayas A (2019) Determinants of declining water quality. World Bank, Washington, DC. http://hdl.handle.net/10986/33224 26. Ewing GN (1985) Instrumental method of chemical analysis. McGraw Hill Book Company, New York, p 624. ISBN 978-0070198517

Chapter 12

Water Quality Rating of Kolkata Waterbodies

Abstract Kolkata’s wetlands not only provide breathing oxygen or keep the surrounding environment cool, but these wetlands also provide huge fish produce by which the fishing community sustains its livelihood by fish farming in the wetlands. But the serious polluting substances cause a decrease of water quality in Kolkata wetlands principally by human interference. Kolkata water bodies are polluted mainly by the inorganic and organic solid wastes, toxic chemicals, and organic compounds etc. which are generally found in the wastewater coming from the domestic discharges. The analytical results of the surface water samples collected from the different water bodies in and around Kolkata metropolis show the extreme deterioration of water quality of the waterbodies which are even unusable for outdoor bathing. Keywords Waterbodies · Water quality index · Conductivity · Turbidity · Wetlands · Remedies of pollutants

12.1 Urban Wetlands West Bengal ranks third in India in terms of number of wetlands after Tamil Nadu and Uttar Pradesh. The total number of wetlands in West Bengal is 147,826 out of which the number of wetlands less than 2.25 hectares is 138,707. The total area of wetlands in West Bengal is 11,07,907 hectares. Again, among the cities of West Bengal, Kolkata metropolis has the highest number of wetlands out of which only sewage-fed fish tanks numbered 254 in East Kolkata [11]. The area of sewage-fed waterbodies for vegetables and fish farming in and around Kolkata is the largest in the world where farming of vegetables and fish is going on by recycling urban sewage wastewater. Such wetlands in East Kolkata supply 18,000 tons of fish daily and the farmers grow and sell about 150 tons of vegetables in Kolkata markets daily by using the wastewater from the sewage-fed wetlands. Due to these reasons, the wetlands of

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024 G. K. Das, River Systems of West Bengal, Springer Water, https://doi.org/10.1007/978-3-031-53480-5_12

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12 Water Quality Rating of Kolkata Waterbodies

the city of Kolkata play an important role in all aspects. Apart from these wetlands, there are several wetlands in and around the city of Kolkata whose role in tourism and recreation is undeniable (Fig. 12.1). Water of such wetland is polluted due to release of domestic wastewater discharge in the water bodies of Kolkata. Water pollution may lead to health hazards to aquatic life of these waterbodies. Therefore, water conservation through maintenance of water quality is urgently needed in the said water bodies. Surface water samples were collected and analyzed in order to identify the pollutants and their sources. Some remedial measures are suggested to maintain the water quality in Kolkata wetlands [17]. Depletion of water quality in wetlands may lead to the result of both water pollution and health hazards to aquatic life. Thus, in turn, may cause biological magnification even in the physique of human beings. Human pressure, rapid urbanization, building constructions, small scale industries etc. are the identified causes spotted for decaying wetlands surrounding Kolkata metropolis disturbing the ecological balance of the area [19]. The wetland from the eastern part of Kolkata is the gateway for ventilating adequate oxygen along with the dense green vegetation resulting in decreasing the rise of temperature of greater Kolkata and Kolkata metropolis during summer (Fig. 12.2). Recently, cementing of banks was planned and executed by the executive engineers of Kolkata Metropolitan Development Authority (KMDA) in order to stop bank erosion which may lead to severe impact in destroying wetland ecosystems where water quality has gradually been depleting with time [7]. The wetland bank contains a number of species that not only assist the carbon sink but also the plants are worthy for their medicinal values [12, 13]. Surface waters of wetlands of Kolkata and its surrounding zone are polluted mainly due to domestic wastewater discharges from the surrounding locality, ground water run off during rainfall and various anthropogenic activities like washing, bathing, throwing of solid wastes like polyethene, plastic packets, papers, rotten foods, flowers, fruits, toxic chemicals, batteries, building materials etc. [23]. Keeping clean, healthy, pollution-free surface water of wetlands in and around Kolkata metropolis is necessary because anthropogenic activities have gradually been increasing in the urban areas in greater Kolkata. Wetlands are important for cooling surrounding ambient temperature during summer as well as water source for quench of any incidental fire. National water policy was introduced in 1987 considering water as a basic human need and precious national asset. For these reasons, wetland conservation through maintenance of water quality is essential in the present time [20]. Estimation of pollution level through analysis of dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, oil and grease etc. and determination for the suggestion of affordable remedial measures for the lowering of water contamination as well as pollutants below permissible level of these waterbodies will be helpful for catering the health of wetlands.

12.1 Urban Wetlands

Fig. 12.1 Rabindra Sarovar Waterbody in the heart of the city of joy

173

174

12 Water Quality Rating of Kolkata Waterbodies

Fig. 12.2 The waterbody of Rabindra Sarovar, also known as Dhakuria Lake, where all types of anthropogenic activities like washing of cloths and cooking utensils, outdoor bathing, throwing of solid wastes like polyethene, plastic packets, papers, rotten foods including flowers and fruits for the activities for religious rituals or festivals are completely prohibited by the Kolkata Metropolitan Development Authority

12.2 Wetland Vegetation Wetland plants especially with submergence characteristics are important for rendering assistance in lowering the pollution level of wetland waters through various other natural processes. People living around the waterbodies can also enjoy the benefit of wetland productivity without destroying an important habitat of medicinal plants grown naturally [12, 13, 15]. More than 14 species of medicinal plants were identified around wetlands like Jadavpur University Lake when a weed eradication drive was taken by the university management. Wetland plants are classified depending on their submergence characteristics [18, 20, 23]. These are (i) submerged plants (e.g., Hydrilla sp.); (ii) free floating plants (e.g., Eichhornia sp.), (iii) rooted but floating plants (e.g., Nelumbo sp.); (iv) rooted and emerged plants (e.g., Colocasia sp.). Some wetland plants including medicinal plants are identified surrounding the water bodies in and around Kolkata megacity (Table 12.1).

12.4 Surface Water Analysis Table 12.1 Medicinal plant species surrounding waterbodies in and around Kolkata metropolis

175

Serial number

Local name

Scientific name

1

Dhutra

Datura metel

2

Basak

Adhatoda vasica

3

Kalmegh

Andrographis paniculata

4

Tulsi

Oscimum sanctum

5

Brahmi

Bacopa monnieri

6

Kulekhara

Hygrophila auriculata

7

Keshardam

Ludwigia adscendens

8

Gima

Polycarpon prostratum

9

Amrul

Oxalis corniculata

10

Thankuni

Centella asiatica

11

Hincha

Enhydra fluctuans

12

Ashwagandha

Withania somnifera

13

Kanchira

Commelina benghalensis

14

Mutha

Cyperus rotundus

12.3 Physicochemical Characteristics Surface water samples from eleven stagnant water bodies in and around Kolkata metropolis were collected for the estimation of physicochemical parameters of surface waters. Samples of surface water from the selected water bodies were collected in polythene bottles of 1 L capacity. Physicochemical parameters like pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, oil and grease were estimated using standard methods and standardized equipment [4, 25]. The water quality index is computed using statistical methods [21].

12.4 Surface Water Analysis Surface water samples were collected from eleven stagnant waterbodies standing in and around Kolkata megacity. It is observed after analyzing the collected water samples that the values of biochemical oxygen demand for most of the waterbodies exceed the permissible level except for the lake of Jadavpur University campus. The biochemical oxygen demand value of all wetlands is low, even sometimes below detectable level during the monsoon period because of dilution due to excess rainfall [16]. Chemical oxygen demand value indicates the requirement of oxygen to oxidize biologically degradable and non-biodegradable organic matter. For this reason, chemical oxygen demand values are always greater than the corresponding biochemical oxygen demand values. Chemical oxygen demand values of Kalpukur tank, Dhakuria

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12 Water Quality Rating of Kolkata Waterbodies

Lake with cemented bank, Bikramgarh Jheel is above the permissible level probably due to higher concentration of organic matter. Mentionably, values of chemical oxygen demand of surface waters affected with domestic discharges is considered to be objectionable for the surface water. In most cases biochemical oxygen demand levels are higher than dissolved oxygen in surface waters because bacteria need dissolved oxygen to oxidize for the stabilization of organic matters through decomposition [5-7]. The dissolved oxygen of five collected surface water samples is shown within the range of 6.0–8.5 mg/l which is taken as optimum for the temperature range 20–30° (Table 12.2). The dissolved oxygen of the remaining samples shows below the optimum (6.0–8.5 mg/l) and dissolved oxygen is depleted in these samples where biochemical oxygen demand is high [9]. A very high value of dissolved oxygen is not prescribed for the surface water due to the high rate of eutrophication. Table 12.2 Analysis of surface water samples of the waterbodies in and around Kolkata Sample No. and location

pH

Conductivity Turbidity TDS TSS DO BOD COD Oil and (Mhos/cm) (NTU) (mg/ (mg/l) (mg/ (mg/l) (mg/l) Grease l) l) (mg/l)

Subuddhipur 7.39 0.67 (K1)

6

32

0.21

3.3

14.3

48

2.1

Baruipur (K2)

7.43 0.65

5

31

0.014

3.6

21.7

92

4.8

Kalpukur (K3)

7.52 0.56

15

23

0.35

3.1

26.6

128

4.9

Dhakuria Lake (cemented bank) (L1)

7.23 0.19

3

9

0.45

6.3

23.4

136

1.9

Dhakuria Lake (L2)

7.61 0.14

4

23

0.12

4.1

19.5

93

5.7

Bikramgarh Lake (BG1)

7.84 1.016

3

126

0.78

7.3

29.7

215

3.9

Nandan Nagar Lake (N1)

7.29 1.069

3

50

0.04

4.2

23.1

52

12.7

Bibek Nagar 7.81 1.06 Lake (J1)

12

37

0.19

6.7

21.6

40

14.28

Jadavpur University Lake (JU)

7.77 1.01

11

53

1.14

4.2

22.2

12

8.57

Hedua Lake (H1)

8.06 1.07

20

26

2.02

7.2

26.4

84

14.21

College Square (CS)

7.83 1.02

8

13

2.22

6.8

21.6

72

10.1

12.6 Remedial Options

177

Table 12.3 Water quality index values of the water bodies in and around Kolkata metropolis Name of wetlands Subuddhipur Tank

WQI 85.31

Name of wetlands

WQI

Nandannagar Jheel

114.42 105.08

Baruipur Jheel

164.71

Bibeknagar Jheel

Kalpukur Tank

228.99

Jadavpur University Jheel

Dhakuria Lake (Cemented Bank)

220.95

Hedua Swimming Pool

161.28

Dhakuria Lake

165.88

College Square Swimming Pool

150.22

Bikramgarh Jheel

287.24

97.07

The permissible range of pH is 6.8–9.0 for sustaining living organisms in wetlands. The pH value of all collected surface samples is well within the range. The values of turbidity and total suspended solids go parallel. It is observed from the data pool that when turbidity of surface water samples is high, total suspended solids of the samples are also high and vice versa [1, 2, 24]. Conductivity and turbidity of the samples are well within the permissible limit except the Kalpukur Lake. Oil and grease concentration more than 10 mg/l is harmful to the wetland biota. The oil and grease value are objectionably high for Nandan Nagar Jheel, Jheel Road Lake, Hedua Lake, and College Square swimming pool. Oil and grease are harmful for surface water as it remains suspended at the surface creating a very thin layer due to less specific gravity of it than the water. This thin layer of oil and grease acts as the separating membrane between air and water.

12.5 Water Quality Rating Calculated values of water quality indices based on the values of physicochemical parameters of the surface water samples show that the water quality of all the waterbodies is in poor conditions as per the chart of the standard values for water quality rating (Table 12.3). The reasons behind such poor water quality of the water bodies are due to the man-made pollution and surface runoff during heavy rainfall in the monsoon period. Surface runoff moves towards the waterbodies along with the thrown materials by the locals living surrounding the waterbodies in the Kolkata metropolis.

12.6 Remedial Options Identification of sources for polluting substances is essential for maintenance of wetland water quality. The possible sources are ground water runoff, domestic wastewater discharges and human activities [1, 14]. Proper law and order banning human interference will lead to a better aquatic environment of waterbodies. Manual

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cleaning operations such as collection of non-biodegradable plastic and fibers by fine screened net may be performed. Several other methods like aeration, flash mixing, filtration, disinfection etc. may be suggested for water purification [1, 3]. Application of Chloramines is useful for disinfection. Aeration enhances inclusion of dissolved oxygen in the water. Alum helps in cleaning turbid or sediment laden water. Unpleasant odour is removed from the water with the application of activated charcoal and it (charcoal) clears, cleans, and purifies wetland waters. Another remedial step may be taken through coagulation and flocculation of dissolved and suspended solids adding foreign chemicals to the surface waters [10, 14, 22]. Lime alum, ferric chloride, ferrous ammonium sulphate (FAS) may be used as coagulants based on the nature and quality of raw water.

12.7 Wetland Commons The urban waterbody is like a breath of fresh air around which many people from old to young come for a morning walk. In the noon day-labourers or hawkers who come from the village to the city for work take a rest under the shade of the trees around the wetlands. At that time the washerman cleans the clothes on one side of the waterbody. Before the arrival of the morning walkers, the fishermen pull the nets and send the fish to the market. In the afternoon, the young men and women come and find the shade of the swamp trees and tell the secret they have kept in their hearts. Later in the afternoon, the children come holding the mother’s hand and they play in their own way, sometimes alone, sometimes in groups. The children’s joy and happiness created a heavenly environment around the waterbody. Amidst these activities of the people around the wetlands, the creatures living in the bosom of nature continue their activities as per their whims. The kingfisher takes fish from the swamp water and eats it by sitting on the branches of trees. Marsh rats catch snails, oysters, crabs and eat them. Common carps move among the algae and fill their stomachs by swallowing phytoplankton and zooplankton. Under the water of the swamp, snails search for food by crawling over the crusty detritus material. And this is how the food chain and food web of a wetland ecosystem are not only maintained, but also the society (human) and nature (ecological) shared interdependence are going to be correlated surrounding the environment of a waterbody indicating the network of socio-ecological systems i.e., wetland commons [22]. But unfortunately, the number and area of wetlands in the megacity of Kolkata is decreasing. If Kolkata city’s wetlands continue to play their mournful farewell music, the temperature in the urban areas will continue to rise as a consequence in the near future. Now, the temperature in Kolkata often exceeds 42 °C during summer. The supply of fresh oxygen to the city will begin to decrease. Prevention of mosquito-borne diseases like malaria, dengue, encephalitis etc. will be difficult if mosquito larvae are not destroyed by swamp-dwelling frogs, techokha, koi, tilapia, Niloticus mozambique and lyata fishes. The next generation will cease all morning

References

179

exercise pleasures and evening excursions. Flat-dwelling teenagers of the city will no longer find a place to talk in private. No more chirping insects can be heard around the waterbody. In the evening, nobody can see the flickering and burning of Jonaki (firefly). In the rainy season, the frogs’ longing calls for mating will no longer be heard. No more will people see the eager wait of a heron for a fish, the swiftness of a kingfisher, or the spiral swimming of a water snake coloured and designed with black-and-yellow mosaics.

12.8 Summary Due to climate change the temperature is rising all over the world from which the city of Kolkata is not spared. Wetlands help keep Kolkata cool in the face of rising temperatures. Maintenance of water quality is very much essential in such wetlands in Kolkata metropolis as water is life giving treasure to all living things like plants, and animals including human beings [8, 15]. It is observed from the analytical results that waters of most of the wetlands in Kolkata are polluted and even in critical condition. The water quality of the swimming pools like College Square and Hedua Park is in an alarming stage because several parameters for the water quality determination are beyond permissible range with fluctuating seasonal variations. If the level of pollution increases like this, it will be difficult for the wetlands of Kolkata to exist.

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