The Nahal Tanninim Dam and Its Vicinity: Final Report of the 2000-2005 Excavation Seasons 9789654067713, 9789654067720, 9654067714

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IAA Reports, No. 71

The Nahִal Tanninim Dam and Its Vicinity Final Report of the 2000–2005 Excavation Seasons

Yosef Porath, Uzi ‘Ad and ‘Abed al-Salam Sa‘id

With contributions by

Donald T. Ariel, Etan Ayalon, Yehoshua (Yeshu) Dray, Amir Freundlich, Peter Gendelman, Avner Hillman, Moshe Izra’eli, Eriola Jakoel, Nili Liphschitz, Yossi Nagar, Yehuda Peleg, Irina Segal, Leah Di Segni, Yonel Sharvit and Tamar Winter

JERUSALEM 2023

IAA Reports Publications of the Israel Antiquities Authority Editor-in-Chief: Zvi Greenhut Series and Production Editor: Shelley Sadeh Volume Editors: Debi Manor and Shelley Sadeh Editorial Board: Yuval Baruch, Zvi Greenhut, Yael Gorin-Rosen, Doron Ben-Ami Front Cover: The Naḥal Tanninim Dam, looking northwest (photograph, Assaf Peretz) Back Cover: Views of the Naḥal Tanninim Dam (photographs, Tsila Sagiv; Kovlonov Archives, Kibbutz Ma‘agan Mikha’el) Cover Design, Layout, Typesetting and Production: Ann Buchnick-Abuhav Illustrations: Dov Porotsky, Natalya Zak Printing: Digiprint Zahav Ltd. Copyright © 2023, The Israel Antiquities Authority, Jerusalem POB 586, Jerusalem, 91004 ISBN 978-965-406-771-3 EISBN 978-965-406-772-0 www.antiquities.org.il

Contents

ABBREVIATIONS

v

PREFACE

vii

FOREWORD

Moshe Izra’eli

ix

CHAPTER 1: INTRODUCTION

Yosef Porath, Uzi ‘Ad, ‘Abed al-Salam Sa‘id and Yehuda Peleg

1

PART I: THE ARCHAEOLOGICAL STRATA (V–I)

Yosef Porath, Uzi ‘Ad and ‘Abed al-Salam Sa‘id

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

13

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

43

CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

101

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

123

 Appendix 5.1: The Provenance of the Basalt Millstones

157

Irina Segal

CHAPTER 6: THE KURKAR QUARRIES (STRATA V–II)

161

CHAPTER 7: OTHER STRUCTURES IN THE VICINITY OF THE DAM (STRATA IV–II)

177

PART II: THE FINDS CHAPTER 8: THE POTTERY

Peter Gendelman

191

CHAPTER 9: THE GLASS FINDS

Tamar Winter

229

CHAPTER 10: THE COINS

Donald T. Ariel

249

CHAPTER 11: A BILINGUAL INSCRIPTION

Leah Di Segni

255

CHAPTER 12: METAL AND WOOD FINDS FROM THE

Etan Ayalon and

261

DAM AND THE FLOUR MILLS

Yehoshua Dray

CHAPTER 13: WOOD OBJECTS

Avner Hillman and Nili Liphschitz

CHAPTER 14: WOOD AND METAL FINDS FROM THE Etan Ayalon OPERATING SYSTEMS OF THE OTTOMAN FLOUR MILLS

275 279

iv CHAPTER 15: CERAMIC TOBACCO PIPES

Yonel Sharvit

297

CHAPTER 16: FOUR BOARD GAMES

Eriola Jakoel and Uzi ‘Ad

325

CHAPTER 17: HUMAN SKELETAL REMAINS

Yossi Nagar

331

Yosef Porath, Uzi ‘Ad and ‘Abed al-Salam Sa‘id

337

PART III: DISCUSSION AND SUMMARY CHAPTER 18: DISCUSSION AND SUMMARY

REFERENCES

345

APPENDIX 1: CONSERVATION AND RECONSTRUCTION WORK ON THE DAM, THE LOW-LEVEL AQUEDUCT AND THE MILLS

351

Amir Freundlich

APPENDIX 2: LISTS OF LOCI AND WALLS

375

v

Abbreviations

AASOR

Annual of the American Schools of Oriental Research

AE

L’Année épigraphique. Paris. 1888–

AIHV

Association internationale pour l’histoire du verre

ASOR

American Schools of Oriental Research

‘Atiqot (ES)

English Series

‘Atiqot (HS)

Hebrew Series

BAIAS

Bulletin of the Anglo-Israel Archaeological Society (Strata BAIAS from 2009)

BAMA

British Academy Monographs in Archaeology

BAR Int. S.

British Archaeological Reports International Series

BASOR

Bulletin of the American Schools of Oriental Research

BDASI

Bulletin of the Department of Antiquities of the State of Israel (Alon; Hebrew)

BGU

Berliner Griechische Urkunden (Ägyptische Urkunden aus den königlichen [staatlichen] Museen zu Berlin, Griechische Urkunden). Berlin 1895–

DOP

Dumbarton Oaks Papers

ESI

Excavations and Surveys in Israel

HA

Ḥadashot Arkheologiyot

HA–ESI

Ḥadashot Arkheologiyot–Excavations and Surveys in Israel

IEJ

Israel Exploration Journal

IJES

Israel Journal of Earth Sciences

JAS

Journal of Archaeological Science

JGS

Journal of Glass Studies

JRA

Journal of Roman Archaeology

JSOT

Journal for the Study of the Old Testament

JSP

Judea & Samaria Publications

LA

Liber Annuus

MA

Mediterranean Archaeology

NEAEHL

E. Stern and A. Lewinson-Gilboa eds. New Encyclopedia of Archaeological Excavations in the Holy Land 1–4. Jerusalem 1993

NEAEHL 5

E. Stern ed. The New Encyclopedia of Archaeological Excavations in the Holy Land 5: Supplementary Volume. Jerusalem 2008

vi OBO.SA

Orbis Biblicus et Orientalis Series Archaeologica

PBSR

Papers of the British School at Rome

PEQ

Palestine Exploration Quarterly

PEFQSt

Palestine Exploration Fund Quarterly Statement

PIR

Prosopographia Imperii Romani Saeculorum I–III. Berlin–Leipzig 1933–

PMich.

Michigan Papyri. Ann Arbor 1933–

QDAP

Quarterly of the Department of Antiquities of Palestine

SB

F. Preisigke et al., Sammelbuch griechischer Urkunden aus Ägypten. Strassburg, Berlin–Leipzig–Heidelberg 1913–

SBF

Studium Biblicum Franciscanum

SEG

Supplementum epigraphicum graecum. Leiden 1923–

ZDPV

Zeitschrift des deutschen Palästina-Vereins

ZPE

Zeitschrift für Papyrologie und Epigraphik

vii

Preface

This volume describes the results of the excavations at the Naḥal Tanninim Dam (map ref. 1918–24/7166–74), conducted over ten excavation seasons during the years 2000– 2005 on behalf of the Israel Antiquities Authority (IAA), initiated by the Carmel Drainage Authority and the Israel Nature and Parks Authority, and financed by the Israel Ministry of Environmental Protection, the Carmel Drainage Authority and the IAA. The excavations were directed by ‘Abed al-Salam Sa‘id and Uzi ‘Ad (Permit Nos. A-3356/00, A-4030/03) and by Peter Gendelman (Permit No. A-4324/04). Chapter 1 is a brief introduction by Yosef Porath, Uzi ‘Ad, ‘Abed al-Salam Sa‘id and Yehuda Peleg of the general background of the site, the history of research, the local environment and the reasons for the current excavations. Part I provides a detailed description by the authors of the stratigraphy revealed in the archaeological excavations: Chapter 2 discusses the ‘pre-dam’ stratum (Stratum V), Chapter 3 the two strata of the dam (Strata IV–III), Chapter 4 the low-level aqueduct to Caesarea (Stratum IV) and Chapter 5 the flour mills operated by the dam water (Strata IV–III), with an appendix by Irina Segal on the provenance of the basalt millstones. Chapter 6 describes the kurkar quarries (Strata V–II) and Chapter 7 the other structures in the vicinity of the dam (Strata IV–II). Part II describes the varied finds discovered during the excavations, including the pottery by Peter Gendelman (Chapter 8), the glass by Tamar Winter (Chapter 9), the coins by Donald T. Ariel (Chapter 10), a Greek and Latin inscription by Leah Di Segni (Chapter 11), the metal and wood items from the dam and mills by Etan Ayalon and Yehoshua Dray (Chapter 12), a description of the wooden framework for the dam’s foundations by Avner Hillman and an analysis of wood samples by Nili Liphschitz (Chapter 13), the wood and metal finds from the operating systems of the Ottoman flour mills by Etan Ayalon (Chapter 14), the Ottoman ceramic tobacco pipes by Yonel Sharvit (Chapter 15), four board games by Eriola Jakoel and Uzi ‘Ad (Chapter 16), and the human remains by Yossi Nagar (Chapter 17). Part III Chapter 18 is a discussion and summary of the excavations and the finds by the excavators. Finally, the conservation and reconstruction works carried out at the site are described by Amir Freundlich (Appendix 1). Appendix 2 contains the Lists of Loci and Walls. We wish to thank the following people who assisted in the excavations and the publication of this volume: Amani Abu-Hamed (area supervisor), the late Shlomo Ya‘aqov Jam (administration), Vadim Essman, Viatcheslav Pirsky, Rivka Mishayev, Anwar Amara and Avraham Hajian (surveying), Natalya Zak, Ira Brin, Elizabetta Belshov and Dov Porotsky (drafting), Tsila Sagiv and Assaf Peretz (field photography), Yossi Nagar (physical anthropology), Giora Ben Ya‘acov and Assaf Peretz (photographic scanning), Roni Gat and Elisheva Kamaisky (pottery restoration), Olga Shorr (glass restoration),

viii

Lena Kupershmidt (metallurgical laboratory), Clara Amit, Yael Yulovitz and Assaf Peretz (studio photography), Marina Shuiskaya and Carmen Hersch (finds drawing), Sky View Photography Ltd. and Assaf Peretz (aerial photography), Yehoshua (Yeshu) Dray (technical consultation), and Yoram Saad and his team: Yigal Merom, the late Yigal Hantiyev, Avner Hillman, Dani Sivoni, Edward Kolick, Ami Sabah and Amir Freundlich (IAA Conservation Department). We were further assisted by the late Yehuda Peleg, the late David Amit and the late Avner Raban, as well as the late Yehudit Ayalon, the employees of the Koblanov Archive at Kibbutz Ma‘agan Mikha’el, and the administrators and workers of the Israel Nature and Parks Authority at the site. This volume was brought to final publication by the IAA Publications Department, and we wish to thank the head of the department Zvi Greenhut, the IAA Reports series editor Shelley Sadeh, the editor Debi Manor, the graphic artists Ann Buchnick-Abuhav and Dov Porotsky, and Rachel Kudish-Vashdi who assisted with the final proofreading. Yosef Porath, Uzi ‘Ad, ‘Abed al-Salam Sa‘id Jerusalem 2023

Foreword Moshe Izra’eli Director of the Carmel Drainage Authority

The area under the jurisdiction of the Carmel Drainage Authority, established in 1997, incorporates the region’s drainage basins, in which the ancient Naḥal Tanninim Dam is located. The area is bordered on the east by the watershed of the Carmel Ridge and the Menashe Hills, on the south by the northern watershed of Naḥal ‘Iron and Naḥal Ḥadera, and on the west by the Mediterranean Sea. One third of this area is the drainage basin of Naḥal Tanninim, which flows through the dam. As three additional streams (Naḥal Barqan, Naḥal Mishmarot, Naḥal ‘Ada) flow into Naḥal Tanninim, which serves as their outlet to the sea, the ancient dam across the gap in the kurkar ridge between Jisr ez-Zarqa and Ma‘agan Mikha’el (see Chapter 1: Fig. 1.1) is a significant obstacle for flood waters from these four streams. Due to the topographic structure of the Carmel coast, none of the Carmel Ridge’s east–west streams north of Naḥal Tanninim as far as Tel Shiqmona, Haifa (Naḥal Tira, Naḥal Gallim, Naḥal Oren, Naḥal Me‘arot, Naḥal Maharal, Naḥal Daliya) has a natural outlet to the sea––they are all blocked by the kurkar ridge parallel to the coastline. This caused inland troughs and flood plains to form along the Carmel coast, between the Carmel slopes on the east and the kurkar ridge on the west (see Chapter 1). This was a serious problem in ancient times, hindering agriculture and obstructing transportation. In order to solve this drainage problem, artificial outlets were hewn through the kurkar ridge. Some of these fascinating millennia-old drainage operations are preserved to this day, such as the hewn channel of Naḥal Daliya, spanned by an ancient bridge. The Naḥal Tanninim Dam is an ancient water facility constructed across the natural breach of Naḥal Tanninim and Naḥal ‘Ada through the kurkar ridge. It was designed to create a reservoir with a water level of approximately 6 m above sea level, to supply water to the city of Caesarea and operate numerous water mills. During torrential rainstorms, it could result in the creation of extensive flood plains, and indeed, in two such events from recent years—1992 and 1995—the dam caused wide-scale inundation and the closure of Highway 2, and severe flooding in nearby settlements. In addition, the central 30 m long segment of the dam is 1 m lower than its northern and southern ends, and the torrential flow gushed over the central segment, cascading onto the foundations of the air-face side and threatening their preservation. As a result, the Carmel Drainage Authority was established to find a solution and prevent recurrences. The authority commissioned the offices of LaviNatif Engineering and Consultants Ltd. (henceforth, Lavi-Natif) to conduct a hydrological survey, which concluded that the flow capacity through the dam had to be increased to 150 cu m per second, or at least four times that of the existing outlets, and thus additional outlets needed to be breached in the dam. This proposal was categorically rejected by the Israel Antiquities Authority (IAA), the Israel Nature and Parks Authority, the Society for

x

the Protection of Nature in Israel, and other environmental bodies, due to concern for the irreparable impact on such an important site. Discussions were conducted to resolve the conflict of interests between the various bodies involved, and an agreement was reached in 2000 to cooperate on developing the dam site as a National Park. Thus, the Naḥal Tanninim Dam Project was established, directed by the author on behalf of the Carmel Drainage Authority, by Dror Barshad, former District Archaeologist for the Haifa Region, Ya‘acov Sheffer, former head of the Conservation Department and Yosef Porath, former Director of IAA Excavations at Caesarea, on behalf of the IAA, and Ze’ev Margalit, former Director of Conservation and Development, on behalf of the Israel Nature and Parks Authority. The main goals of the project were to increase the flow capacity of the dam to prevent further flooding, and to excavate, reconstruct and operate the dam’s ancient hydraulic facilities (sluices, gates, winches, etc.) and flour mills. Archaeological excavations began in December 2000, exposing the ancient sluice outlets, the adjacent channel system and other outlets in the dam. It became clear that a fascinating site was being uncovered, and that by studying the design of the dam’s original builders and later users, solutions could be found to the modern drainage problems. The archaeologists were faced with the dilemma of what to disassemble and which period to preserve. For example, should the relatively more recent Ottoman channels be removed to expose the ancient channels from the Late Roman–Byzantine period? Obviously, each archaeological decision was also significant from the drainage perspective. The decision was made to recreate the way in which the site had operated and functioned during the Byzantine period, some 1650–1350 years ago, and how the water was channeled to supply the city of Caesarea as well as to operate the ancient flour mills. Following the excavation season in the summer of 2001, all the existing outlets in the dam had been excavated, cleaned and surveyed (Fig. 1),1 and the total flow capacity had been increased from c. 35 cu m per second to 80–90 cu m per second. However, during heavy rains in December 2001, water continued to flow through gaps in the stone walls and wash out the mortar from the dam’s core, forming voids, and there was fear of internal collapse. Moreover, now that the dam had been excavated to its foundations and was no longer supported by earth on both sides, it became apparent that with insufficient drainage, a head of water 4–6 m deep would accumulate on the water-face side and severely damage the dam. A further examination by Lavi-Natif established that the combined potential flow rate of the dam’s outlets was still insufficient. The dam’s present potential flow capacity of 80–90 cu m per second, when the water level in the reservoir was 5.10 m asl, would be insufficient when flooding produced a flow rate of 150 cu m per second, and Highway 2 would still be inundated. Subsequently, a planner from Lavi-Natif, Gadi Yom-Tov, suggested enlarging the three existing modern breaches—two of Naḥal ‘Ada and one of Naḥal Tanninim—which would have minimal impact on the archaeological site. This

These also included three modern breaches––the Naḥal Tanninim outlet and the northern and southern outlets of Naḥal ‘Ada––made by the Palestine Jewish Colonization Organization (PICA) in 1924, and later by Dov Kovlonov of the Jewish Agency, to drain the Kebara Swamps (see Chapter 1: Plan 1.1). 1

xi

M16 P4

M10

P3 a

M11

M12

Ottoman?

P2 P1 Naḥal ‘Ada

Naḥal Tanninim

b

Fig. 1. The outlets in the dam, before (a) and after (b) the excavations, looking west.

involved (1) removing parts of the original dam wall near the entrance to the southern outlet of Naḥal ‘Ada and widening the outlet by 2.0 m to 3.5 m; (2) deepening the threshold of the northern outlet of Naḥal ‘Ada from 1.85 m to 0.25 m asl; (3) deepening the floor of one of the three sluice passages from 3.6 m to 0.5 m asl, with equivalent deepening of the channel to its west. This would enable a total of 135 cu m of water per second to flow through the dam. A flow rate of 150 cu m per second would still cause Highway 2 to be inundated, but much less severely. Thus, it was decided to act immediately to improve the modern outlets according to Lavi-Nataf’s proposal, except for the deepening of the floor of one of the sluice channels, which would be compensated by the enlargement of the Naḥal ‘Ada outlets. A resulting flow rate of 140 cu m per second ultimately surpassed the initial goal of 135 cu m per second. In the first stage of reconstruction, following the 2002 excavation season, the three modern breaches in the dam were cleaned and enlarged, according to the recommendations of Gadi Yom-Tov (above) and the dam was carefully sealed. A smaller version of the original water reservoir formed by the dam was created to the southeast, and drainage from the reservoir was now through the three passages of the sluice (Figs. 1, 2). In the second stage, submerged pumps were installed in the lower reaches of Naḥal Tanninim, and pipes were installed to carry water to this reservoir. A system was designed to catch the water that had once passed in a section of the stream and convey it to the reservoir, from where it would flow back, through the original passages in the sluice, to rejoin the modern course of the stream. In this way, new ecosystems and habitats would develop (Fig. 3).

xii

Fig. 2. View of the reconstructed reservoir from the modern bridge over the sluice, looking northeast.

Fig. 3. Reconstructed passages in the sluice, looking west.

In the following stage, sluices, gates, lifting winches and mill wheels were reconstructed, and it is impossible not to mention here the unique contribution of Yehoshua (Yeshu) Dray, who used the remains of markings on the rock to interpret the way in which the ancient facilities had operated, and to subsequently reconstruct them and render them functional as in the past (Figs. 4, 5)

xiii

In retrospect, this may be the first case in which modern drainage needs have resulted in providing the wider public with a fascinating reconstructed archaeological site and a national park.

Fig. 4. Reconstructed Ottoman-period flour mill (M16).

Fig. 5. Reconstruction of a vertical paddle wheel in Mill 6, looking northeast.

Y. Porath, U. ‘Ad and ‘A. a-S. Sa‘id, 2023, Naḥal Tanninim (IAA Reports 71)

Chapter 1

Introduction Yosef Porath, Uzi ‘Ad, ‘Abed al-Salam Sa‘id and Yehuda Peleg

1 Jisr ez-Zarqa

I

3

202 000

200 000

m

ini

n an T l ha Na .

4

714 000

a

hal Na .

d ‘A

712 000

Caesarea

710 000

III 4 200 000

198 000

196 000

194 000

0

km

202 000

‘Ein al-Asal 192 000

708 000

716 000

‘En Shuni

II

190 000

710 000

198 000

196 000

3

I

712 000

2 The Northern Dam 718 000

II 714 000

1 The Naḥal Taninnim Dam

‘En Zabarin .

2

718 000 716 000

194 000

192 000

190 000

The city of Caesarea Maritima, founded by Herod the Great and inaugurated in 10/9 BCE, enjoyed an abundant water supply derived from sources at some distance from the city (Conder and Kitchener 1882:18; Olami and Peleg 1975, 1977; Peleg 1989; Porath 2002a; Porath and ‘Ad 2015). At this stage of research, three systems are known to have brought water to the city: the High-Level Aqueduct from ‘En Shuni and smaller springs in the upper reaches of Naḥal Tanninim (Fig. 1.1:I; Porath and ‘Ad 2015), the Low-Level Aqueduct from the Naḥal Tanninim reservoir created by the Naḥal Tanninim Dam (Fig. 1.1:II; Peleg 1989, 2002a; Chomicki 2002; Porath, Gendelman and Arnon 2007; Fitton, Reinhardt and Schwarcz 2008), and the southern pipeline from ‘Ein al-Asal in the lower reaches of Naḥal Ḥadera (Fig. 1.1:III; Porath 1990, 2002b:119–120; 2006). Most of the drinking water for the city’s inhabitants was conveyed via the High-Level Aqueduct (Porath and ‘Ad 2015:107).

Fig. 1.1. The water sources of Caesarea Maritima.

708 000

3 The Naḥal Taninnim Reservoir 4 The distribution installation (divisorium) of the High-Level Aqueduct I The High-Level Aqueduct II The Low-Level Aqueduct III The Southern Pipeline

2

YOSEF PORATH, UZI ‘AD, ‘ABED A-S. SA‘ID AND YEHUDA PELEG

The Site The coastal plain of Israel is composed of a series of elongated, aeolian calcareous sandstone (kurkar) ridges, extending subparallel to the Mediterranean coast. Between the ridges are low depressions known as troughs, in which soils accumulated from the adjacent slopes of the kurkar ridges (Karmon 1961; Nir 1970:5–54; Horowitz 1979; Mazor 1980:449; Gvirtzman 1990; Gvirtzman, Netser and Katsav 1998; Tsoar 2000). These kurkar ridges are cut by a few natural channels that drain water westward from the foothills and central mountains, depositing fine-grained alluvial sediments in their path. In the narrow coastal strip between Mount Carmel and the sea, the kurkar ridge was cut by the shared outlet of two streams, Naḥal ‘Ada and Naḥal Tanninim (Fig. 1.2). In the millennia prior to the construction of the Naḥal Tanninim Dam, as a result of climatic fluctuations and rapid sea-level rise at the beginning of the Holocene, wetlands dominated the landscape of the western and eastern troughs along the southern part of the Carmel coastal plain (Chomicki 2002). Until their drainage in 1924, the Kebara Swamps spread from Naḥal Daliya in the north to Bet Ḥananya in the south, on both sides of the kurkar ridge (Fig. 1.2; Ayalon 1987; Krakovsky 1987; Avitsur 1988). Early in the Byzantine period, apparently in the second half of fourth century CE,1 the wetland waters in the eastern trough were raised to an elevation of c. 6 m asl in a reservoir created by the construction of two dams: the Naḥal Tanninim Dam from north to south, which blocked the shared outlet of Naḥal Tanninim and Naḥal ‘Ada, and the Northern Dam from east to west, between the kurkar ridge and the foot of Mount Carmel, which closed off the northern end of the reservoir (Figs. 1.2–1.5; see Karmon 1961; Horowitz 1979:109– 115; Gvirtzman 1990).2 These dams were an essential component in a sophisticated water system that was designed to create the reservoir at a sufficiently high elevation to allow water to flow by gravity via the Low-Level Aqueduct to Caesarea Maritima, to operate flour mills and probably other facilities (such as wood and stone mills, bathhouses, water pools, fountains and flushing toilets in Caesarea), and via the aqueduct to Dor that directed water northward from the Northern Dam (Porath, Gendelman and Arnon 2007). The dams were built according to the finest principles of Late Roman planning and execution, and the Naḥal Tanninim Dam continued to function, with modifications, until the modern breaches in 1924 to drain the Kebara Swamps. The waters of the reservoir powered flour mills, intermittently, from apparently the time the dam was built until 1924 CE. The mills, most of which were unearthed during the current excavations, operated according to various technological means that were modified during the different periods of the dam’s existence (see Chapter 5).

We follow here the chronology of the New Encyclopedia of Archaeological Excavations in the Holy Land (NEAEHL 5:2126), which dates the Byzantine period to 324–638 CE. 2 For a detailed description of the site in the context of Late Pleistocene–Holocene marshes along the Carmel coast, and an analysis of Late Pleistocene–Holocene cores from the region, see Cohen-Seffer et al. 2005. 1

3

CHAPTER 1: INTRODUCTION

194 000

192 000

190 000

The Naḥal Tanninim Dam is unique in Israel, on account of both its dimensions and its state of preservation. Over the centuries, its impressive remains have attracted the attention of travelers, explorers, pilgrims and tourists alike.

Dor

Haifa 722 000

ya

Dali Nah. al

722 000

ridge

Jerusalem

Northern Dam

Kebara Swamps

Ma‘agan Mikha’el

718 000

Mount Carmel

716 000

1

km

194 000

192 000

190 000

0

Kurkar

Nahal Tanninim

l ‘Ada

h.a

.

716 000

Sand

718 000

Timsaḥ Springs

Na

Naḥal Tanninim Dam

720 000

r

Western trough

rka

Mediterrannean Sea

Ku

720 000

Eastern trough

Swamps

Fig. 1.2. The Carmel Coast.

Byzantine dam

4

YOSEF PORATH, UZI ‘AD, ‘ABED A-S. SA‘ID AND YEHUDA PELEG

Fig. 1.3. Aerial photograph of the dam and its environs (January 2003).

CHAPTER 1: INTRODUCTION

Fig. 1.4. The entire length of the dam’s water face with the sluice on the left and the reconstructed reservoir in the foreground, looking northwest (February 2009).

Fig. 1.5. The southern half of the dam’s air face with the sluice, the mills and the Lower Aqueduct into which the Low-Level Aqueduct was inserted, looking northeast (February 2009).

5

6

YOSEF PORATH, UZI ‘AD, ‘ABED A-S. SA‘ID AND YEHUDA PELEG

History of Research The dam on Naḥal Tanninim (‘Crocodile Stream’) is not mentioned in ancient literature and there are hardly any written records of the Low-Level Aqueduct to Caesarea.3 Whereas the flour mills on the Yarqon River (near Tel Aviv) and the Afeq/Qurdani Stream (near ‘Akko/ Acre) are mentioned quite frequently in Crusader documents, no such early mention of the Naḥal Tanninim dam or its mills exists. The French Jesuit monk, Michel Nau, was apparently the first to mention the dam. He described a small stream south of Dor called el-Temasieh (‘crocodile’ in Arabic) that powered some mills (Nau 1757:14). In May 1848, members of Captain Lynch’s expedition to the Jordan River and the Dead Sea passed by the dam on returning to their ship, and the busy mills are mentioned in their report (Lynch 1850:450). William M. Thomson, who visited the dam in April 1857 (Thomson 1881), called the stream Zerka (‘blueʼ in Arabic) and identified it with the Crocodile Stream of antiquity (see Pliny the Elder, Natural History V, 18; Strabo, Geography XVI, 2, 27). According to Thomson’s account, the dam was 230 paces long and 10 paces wide, and the difference between the water levels on the two sides of the dam was 25 feet. He estimated that there were once as many as 20 mills at the dam, some of which lay in ruins, while eight to ten were still in operation. He was much impressed by the dam and its busy mills, in his words: “The grandest milldam I have ever seen” (Thomson 1881:73). The dam is mentioned in a preliminary report by Tyrwhitt Drake (1873), a member of the Palestine Exploration Fund survey team, where it is referred to as Jisr el Zerka, i.e., the bridge on the blue river: The low-level aqueduct comes from the Jisr el Zerka and has a total length of three miles. It is supplied by the Nahr el Zerka, which, at the mills about a mile and a half from the sea, is stopped by a broad dam, which raises the water some twenty feet. Its channel is at first rock-cut, and open at top, but afterwards is a vault of masonry, 7 feet high, and 4 inches wide, built on the low hills bordering the sea (Drake 1873:109). In the Survey of Western Palestine (SWP), the site is also referred to as Jisr el Zerka: This is properly speaking a dam rather than a bridge, built across the river so as to form a large pool. There is a causeway on top of the dam: the height on the west is 20 feet; on the east the level of the water was 3 feet below the roadway. The masonry resembles that of the aqueduct fed from the pool. The eastern face of the dam is cemented. Sluices lined with cement are constructed in the dam. The roadway is 8 feet to 10 feet broad. The work appears to be Roman (Conder and Kitchener 1882:18). The mills are not mentioned in the SWP report, for unknown reasons. As they were then still in operation, they were probably not considered to be within the scope of the survey, which dealt with ancient remains.

According to an Islamic source (al-Bâldhurî), the infiltration of Muslim forces during the occupation of the city in 641/642 CE was through a ditch under the city wall; this may well have been the Low-Level Aqueduct, as proposed by Holum (1992:74). 3

CHAPTER 1: INTRODUCTION

7

In 1877, the journal of the German Templer community, Tempel-Warte, published a letter by the master mason Christian Beilharz, who apparently acted as a building contractor, in which he tells of restoration work on mills at Jisr el Zerka: The mill is situated half an hour inland from the sea, where two valleys meet. These valleys are two hours in length and one hour in width; swamps overgrown with bushes, good cover for boars, crocodiles, hyenas and other game. Above the mills is a basin in which the water is confined and collected by a dam five meters high and about 180 meters long. This masonry structure built of big ashlars, with several big and small passages, was built by the Romans or Crusaders, more probably by the former. There is also a rock-cut channel that brought water to the moat of Caesarea. The mills are of the oldest and simplest type of construct; at present eight are in operation, once there were twelve (Beilharz 1978). In about 1885, Gottlieb Schumacher led an expedition that tried, in vain, to find a live crocodile. However, he produced a good description and some drawings of the Northern Dam (Schumacher 1887:80). In the 1950s, Shmuel Avitsur conducted an extensive study of the Naḥal Tanninim Dam and mills as part of his survey of the remains of water-powered mills and other waterpowered installations in Israel (Avitsur 1963:69–71). The Ottoman mills at the dam are described at length in his report. In his opinion, the dam and the mills were built by Roman legions during the Bar Kokhba Revolt (132–135 CE), and the dam’s main purpose was to power mills to produce flour for the legions stationed at Caesarea at that time. However, subsequent research has determined that the dam was built in the early Byzantine period (see Chapters 3, 18). Avitsur described the operation of the mills at the beginning of the twentieth century, when they even served far-off villages as they were capable of operating all year round, in contrast to most other mills that were dependent on seasonal streams. He regarded these mills as the largest water-powered installation ever built prior to the plant that pumped water to the gardens at Versailles. They continued to be operated into the 1920s. In 1972–1973, a team of the Archaeological Survey of Israel, directed by Ya‘acov Olami, explored the area of the Caesarea Map, including a thorough survey of the Caesarea aqueducts. This survey established that the Naḥal Tanninim Dam and its reservoir were the water source for the Low-Level Aqueduct to Caesarea (Olami and Peleg 1975, 1977; Peleg 1986, 1989). In 1974–1975, Robert J. Bull, director of the Joint Expedition to Caesarea Maritima, conducted soundings at seven unpublished locations along one of the dam’s faces and in the rock-cut channels at its southern end. The expedition’s architect, Edward Russell, prepared a plan of the site. John P. Oleson conducted a field study in 1978 and 1981 and published plans, sections and an isometric drawing of a rock-cut mill installation (Mill 2; see Chapter 5). In the publication, Oleson (1985) compared this mill with the type mentioned by Vitruvius in his Ten Books on Architecture (X.5.2). The plan prepared by Russell is included in that publication, unfortunately in a very scaled-down version. In 1984, Thorkild Schiøler initiated an excavation of the mills at the dam, conducted together with Jørgen Hansen and Michal Artzy in the framework of a Danish–Israeli

8

YOSEF PORATH, UZI ‘AD, ‘ABED A-S. SA‘ID AND YEHUDA PELEG

expedition aimed at researching watermills from the Roman period (Artzy and Schiøler 1984–1986; Schiøler 1989). The team examined a number of mills and excavated one single mill (Mill 12) and one double mill (Mill 11), both constructed against the air face of the dam. At the same time, the staff and students of the field school of the Society for the Protection of Nature at Ma‘agan Mikha’el partially excavated the southernmost double mill (Mill 10). These mills proved to be Ottoman and not Roman. Only the double penstock mill (Mill 14), toward the northern end of the dam, was dated by Schiøler, based on radiocarbon analysis of a wood fragment, to the second half of the fourth century CE; however, this date is in doubt.4 Schiøler’s team sank a probe along the dam’s water face, beneath the opening in the dam that conveyed water to the double mill they had excavated (Mill 11). This probe showed that the water face was originally plastered. They sank another probe in Quarry 2, near the northern wall of the rock-cut passage of the channel of the Low-Level Aqueduct to Caesarea, uncovering a narrow channel that is here termed the Lower Aqueduct, which had been hewn in the pre-dam phase (see Chapter 2). In 1988, within the framework of the Combined Caesarea Expeditions (CCE) sponsored by the University of Maryland and the University of Haifa, surveys and salvage excavations were carried out to the north of Caesarea along the course of the Low-Level Aqueduct (Everman 1992).

The Current Excavations The modern breaches made in the dam in 1924 were sufficient to convey the spring water that gushed into the drainage basin of Naḥal Tanninim and Naḥal ‘Ada and the regular winter runoff. However, in times of heavy precipitation and abundant runoff, the dam would block the torrential flow for a short period and flood the fields on either side. The construction of Highway 2, the expressway between Haifa and Tel Aviv, altered the fragile equilibrium that was created after the Kebara Swamps were drained. Torrential rains in 1992 and 1995 caused inundation of the new road and completely blocked traffic. To prevent a repetition of this occurrence, it was imperative to find a solution to enable the waters of Naḥal Tanninim and Naḥal ‘Ada to flow unhindered to the sea. Thus, the Carmel Drainage Authority joined forces with the Israel Antiquities Authority (IAA) and the Israel Nature and Parks Authority in the Naḥal Tanninim Dam Project, in an attempt to solve the problem without damaging the ancient dam (see Foreword). The archaeological excavations began in December 2000, first under the direction of ‘Abed al-Salam Sa‘id, later joined by Uzi ‘Ad in 2000 and Peter Gendelman in 2004. The main objectives were to investigate the dam’s state of preservation and to expose its original openings to determine if there was a practical way to channel a larger amount of water through the dam. During ten excavation seasons in the years 2000–2005, an extensive area was excavated, c. 1000 m from north to south and 250 m from east to west, according to a

Evidence from the current excavations suggests that the mill actually dates later than the Byzantine period, but earlier than the end of the Crusader period (see Chapter 5). 4

9

97

Q14, Q13, Q12

717 96 300

Building 1

95

n Ta al

Na

M16

192 450

192 400

192 350

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M15 Building 2 B34

D5

87

M14 B31

717 86 200

85

D4

84 83

Dam

82

Built flour mills

D3

M12

D2 M11

78 77

Hewn flour mills

717 76 100

Naḥal ‘Ada southern breach

B10 B9 N2 B7 B6 S2 B3

M10 W1 M13 Q7 D1 M19

Building 3 S1 E1

Q6

Q9

Q5

Q4 Lower Aqueduct

M1-M6

74 73 72

C1

Building 6

P5

Q1

717 050

Q2

Lower Aqueduct

70

717 100

Building 5

Building 4

717 71 050

717 150

Diversion channel

Sluice

Q8

75

717 200

Lower Aqueduct

B31

D6 N4

79

Naḥal ‘Ada

aifa

88

to H

89

717 81 150 80

717 300

m ni

ḥ

Q10

717 91 250 90

T11

ni

Q11

92

192 300

Q3

2

93

T10 T12

Road

94

192 250

192 150

192 200

CHAPTER 1: INTRODUCTION

Low-Level Aqueduct

69 68 67 717 66 000 65

717 000

64 63 62

Q15

716 61 950

716 950

Q16

60

Low-Level Aqueduct

58

B, D, E, S, W = Probes C = Channel M = Flour Mill Q = Quarry T = Burial Cave P = Passage

57 716 56 900 55

54

716 900

to Tel Aviv

Lower Aqueduct

59

53 I

J

K

Q17

L M N O

P

Q

R

S

T U

V W X

Plan 1.1. The Naḥal Tanninim Dam and its vicinity.

Y

Z AA

0

50 m 192 450

H

192 400

F G

192 350

E

192 300

D

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850

Q18 C

192 200

52 51 B 716 A

716 850

10

YOSEF PORATH, UZI ‘AD, ‘ABED A-S. SA‘ID AND YEHUDA PELEG

10 × 10 m grid calibrated to the Israel National Grid (Plan 1.1). The excavations revealed important details of the methods and the means used by the builders of the dam, how it functioned on a daily basis, the alterations made to it over the centuries, and the operation of the flour mills alongside it. In addition, a pre-dam phase was uncovered, which included an ancient aqueduct (the Lower Aqueduct, see Chapter 2), whose floor elevation (max. 3.24 m asl) was lower than that of the Low-Level Aqueduct (max. 5.46 m asl), as well as burial caves and quarries (Plan 1.1; see Chapter 6). The stratigraphic sequence of human activities uncovered in the archaeological excavations was divided into five strata: Stratum V: Pre-dam remains (pre-Roman and Roman periods, prior to the second half of the fourth century CE). Stratum IV: The period during which the dam was built (Phase IVc) and maintained (Phases IVb–a), and supplied water to Caesarea via the Low-Level Aqueduct, and to the flour mills hewn into the kurkar bedrock to the west of the dam (Byzantine period). Stratum III: The period following the abandonment of the dam and hewn mills at the end of the Byzantine period. During this period, the reservoir supplied water to flour mills built adjacent to its air face. This stratum is sub-divided into Phase IIIb (Early Islamic period, mid-seventh–tenth centuries CE; Mamluk period, thirteenth–fifteenth centuries CE) and Phase IIIa (second half of the Ottoman period and early British Mandate period, seventeenth–early twentieth centuries). Stratum II: Remains of the Kebara Swamps drainage works (1924–early 1930s). Stratum I: Accumulations from the drainage of the Kebara Swamps until the commencement of the current excavations (c. 1935–2000). The archaeological excavations carried out at the Naḥal Tanninim Dam and its adjacent mills have expanded our knowledge of Roman engineering capabilities and dam construction, and enriched the features of the Naḥal Tanninim Nature Reserve, turning it into a fascinating site for both scholars and the general public alike.

Part I The Archaeological Strata (V–I)

Y. Porath, U. ‘Ad and ‘A. a-S. Sa‘id, 2023, Naḥal Tanninim (IAA Reports 71)

Chapter 2

The Pre-Dam Stratum (Stratum V)

Extensive remains of human activities that predate the construction of the Naḥal Tanninim Dam were uncovered in the excavations. They can be assigned to a pre-dam stratum (Stratum V), either because they were damaged by the construction of the dam or the Low-Level Aqueduct (Stratum IV), or because they are located below the water level of the reservoir and covered by the sediments that accumulated there. These remains include kurkar quarries, burial caves, an aqueduct (termed here the Lower Aqueduct) and a paved road beside and above the aqueduct (see Chapter 1: Plan 1.1).

Kurkar Quarries Kurkar was a common building stone for thousands of years in the coastal plain in general, and in the central Sharon plain in particular, due to its availability, the relative ease with which it can be quarried, and its low density compared to other building stones in the region (chalkstone, limestone, dolomite). It was first utilized in the earliest permanent settlements in the Sharon plain in the Chalcolithic period and Early Bronze Age (Gophna 1974; Dar 1977; Paley and Porath 1993:610). During Herodian times, the quarrying of kurkar in the northern Sharon plain and the Carmel coast accelerated with the building of Caesarea, where it served as the principal construction material. Surveys have located many quarries to the north and south of the outlet of Naḥal Tanninim and Naḥal ‘Ada through the kurkar ridge (see Chapter 1: Plan 1.1). At least five quarries (Q1, Q3–Q6) were exploited in the period prior to the construction of the dam and the Low-Level Aqueduct to Caesarea (see Chapter 6). The northern part of the Low-Level Aqueduct was built into the eastern part of Quarry 1, while the northern end of the dam meets the hewn wall of Quarry 3. Three small quarries (Q4–Q6), situated along the course of the Lower Aqueduct, were covered by the water of the reservoir and filled up with sediments; thus, they were in operation in the intervening period between the abandonment of the Lower Aqueduct and the accumulation of water behind the dam.

Burial Caves Three burial caves have so far been discovered in the southeastern slope of the kurkar ridge to the northeast of the dam (T10, T11, T12; see Chapter 1: Plan 1.1). They were hewn into a step in the slope that had apparently been created by ancient quarrying (Q3) and then smoothed by the water of the reservoir. The kurkar bedrock in the area of these caves is fractured, and large kurkar blocks have collapsed from the walls and roofs in Caves T10 and T11. Two of the caves were excavated in the framework of the present excavations

14

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

(T10, T11), while Cave T12 was only documented. A fourth burial cave probably existed in the area of the distribution basin and the upper section of Channel 1 (see below). Burial Cave T10 (Plan 2.1) This cave was damaged by looting in antiquity and remained open and empty of finds. It contains an entrance chamber (L6100) and a burial chamber (L6101; Figs. 2.1, 2.2). The entrance chamber (1.8 × 2.3 m) has a vaulted roof (max. height 1.9 m) and in the

1 L6103

2

L6104

L6102 L6105 L6101

L6106

L6100 L6109

L6107

1 L6108 0

2

breach

2

m

7 00

76 00

L6104

L6100

65 00 L6108

L6107

L6106

L6105

45 00

1-1

L6109 L6102

7 00

76 00 L6108

L6100

56 00

2-2

Plan 2.1. Burial Cave T10.

45 00

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

15

southeastern wall is a rectangular entrance (0.8 × 1.3 m; threshold 4.8 m asl). The margins of the entrance are stepped and recessed by 0.15 m at the door jambs and 0.20 m at the lintel (Plan 2.1: Section 1-1). The two inner corners of the lintel have round depressions (10–11 cm diam., 8–9 cm deep) that are the upper sockets for the pivots of the doors. Remains of the lower sockets can be identified in the threshold. On the eastern door jamb, 0.9 m above the threshold, traces of a depression (8–10 cm diam.) were detected, probably for a bolt. The burial chamber (L6101) is rectangular (3 × 4 m) and has a high roof (2.1 m max. height). Seven loculi were hewn in the chamber walls (standard size 0.7–0.8 × 2.1 m, 1.3–1.4 m high) and one arcosolium.

Fig. 2.1. Cave T10, the entrance, looking north.

Fig. 2.2. Cave T10, the burial chamber, looking northwest.

16

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

In the southwestern side are three loculi of standard size (L6106–L6108), and a smaller one (L6105; 0.6 × 0.8 m) apparently intended for the burial of a child or as a repository. The floors of these loculi are 0.1 m higher than the chamber floor. To the south is one loculus (L6109) whose southern part is missing (0.7 m wide, 1.5 m estimated original length); the floor is 0.3 m above the chamber floor. In the northwestern wall are two loculi (L6103, L6104) whose floors are 0.4 m above the chamber floor. A large fissure in this location was apparently known to the workmen when they prepared the cave and for this reason they avoided hewing a third loculus to the west. On the walls of the burial chamber and in the loculi were vestiges of plaster that had originally covered the friable kurkar. The light colored plaster was laid on a gray-plaster foundation layer that contained potsherds (some ribbed). A triangular niche for a lamp was hewn in the southeastern wall of the burial chamber, between the entrance and Loculus 6109, 1.5 m above the chamber floor (Plan 2.1: Section 2-2). A similar niche was hewn in the northwestern wall, above the partition that separates the two loculi. In the northeastern wall is an arcosolium (L6102) containing a trough (0.80 × 1.95 m, 0.70 m high, thickness of side 0.30 m) above which is a hewn vault (1.05 m wide, 2.10 m diam.; Fig. 2.3). The reason for the carving of an arcosolium here was probably the relative proximity to Cave T11 (see below), which left insufficient room to hew out additional loculi. This suggests that the preparation of Cave T11 preceded that of T10. The southern part of the cave collapsed in a later period (of unknown date) creating another opening into the cave at the end of L6108 (see Fig. 2.1). The lower part of the entrance from Chamber 6100 to the burial chamber was widened by 1.6 m, either by looters or eroded by the water of the reservoir, or a combination of both. The western part of the trough in Arcosolium 6102 was also destroyed.

Fig. 2.3. Cave T10, the arcosolium, looking north.

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

17

Burial Cave T11 (Plan 2.2) This cave was damaged by looting in antiquity and remained open and empty of finds. It comprises an entrance chamber (L6110) and a burial chamber (L6111). The entrance chamber (1.20 × 2.20–2.50 m) has a vaulted roof (max. height 2.15 m; Fig. 2.4) and a rectangular entrance in its southeastern wall (0.9 × 1.1 m, threshold 5.02 m asl). The margins of the entrance are stepped and recessed by 10 cm at the door jambs and 20 cm at the lintel (Plan 2.2: Section 2-2). The outer face of the lintel is arched and the inner face is horizontal. Three grooves of unclear function were hewn in the door jambs, one in the upper part of each jamb (south: 11 × 13 cm, 16 cm deep; north: 9 × 11 cm, 6 cm deep) and one (7 × 8 cm) in the northern jamb, 0.96 m above the threshold. No signs of a door pivot were discerned. The rectangular burial chamber (L6111; 3.0 × 3.5 m) has three loculi hewn in each of the northeastern, northwestern and southwestern walls (0.85–0.95 × 1.8–2.3 m, 1.0–1.2 m high). The chamber floor has mostly caved in and was only preserved near the northwestern and southwestern walls. There was no attention to detail in the hewing. The dimensions of the loculi are not uniform and the thickness of the partitions and quality of the finish vary. The floor in the center of Chamber 6111 was originally 0.4 m lower than the level adjacent to the northwestern loculi, perhaps indicating the existence of a standing pit. The floors of Loculi 6112, 6113, 6119 and 6120 were damaged in a later collapse. In the southwestern corner of L6119, a passage to the burial chamber of T10 was created by the widening of a natural fissure. Beneath the three northeastern loculi (L6115–L6117) is a hewn cavity (L6121) that was only partially exposed due to safety considerations. Its southwestern margins are rounded and it may have been part of a semicircular cavity that opened toward Burial

Fig. 2.4. Cave T11, the entrance chamber, looking west.

18

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

1

Chamber 6111 and connected with the probable standing pit in the center of the chamber (Plan 2.2: Section 1-1). It may have served as a repository. Part of the fill in L6121 was cleaned during excavation to 0.4 m below the floor of the burial chamber (c. 0.9 m lower than the floor of the loculi), without reaching its floor.

2

L6115

L6114 L6113

L6116

L6112 L6117 L6111

L6110

L6118 L6119 L6120

1

2

0

L6117

L6116

2

m

8 00

L6115

7 00 L6114

L6118

6 00

L6111 L6121

4 00

1-1 L6120

L6119

5 00

8 00

L6118

L6117 L6110

7 00

6 00

5 00

2-2

Plan 2.2. Burial Cave T11.

4 00

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

19

The lower part of the entrance to Cave T11 was widened to 2.1 m in a later period (Fig. 2.5), like the entrance to Cave T10 (above), either by looters or eroded by water from the reservoir, or both.

Fig. 2.5. Cave T11, the widened entrance from inside the cave, looking southeast.

Burial Cave T12 (Plan 2.3) This cave is located just east of the foundations of the northern edge of the dam’s water face. As entry was only possible through a very small breach (0.4 × 0.5 m) in the southern wall of Loculus 6124, the cave was only documented. It comprises an entrance chamber (L6122), a burial chamber (L6123) and nine loculi. A probe to the east of the foundations of the dam and W215 (L6019; see Chapter 3: Plan 3.11) exposed the entrance chamber (c. 1.5 × 2.0 m; floor elevation 2.5 m asl) with a vaulted roof (max. height 2 m) and an opening to the burial chamber (0.7 × 0.9 m) sealed by a stone slab (0.5 × 0.5 m, length unknown) that remained in situ (Figs. 2.6, 2.7). On the inside of the entrance threshold, two steps were hewn (treads 10 cm, 20 cm; risers 10–15 cm). Burial Chamber 6123 is rectangular in plan (2.6 × 2.9 m), and three loculi were hewn in each of the northern, southern and western walls (0.80–0.85 × 2.10–2.20 m, 0.80–0.90 m high). Remains of a light colored plaster coating on a foundation layer of lime-based mortar with large sherds were discerned on the walls of L6123 and the loculi. The floors of the chamber and the loculi were covered with a friable fill to 1.2 m beneath the roof, apparently formed by erosion and sediments from the Naḥal Tanninim reservoir.

20

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L6130

1

L6129 L6132 L6131

L6128 L6127

L6123 L6122

1 L6126

L6125

L6124

0

2

m

6 00

L6122

L6128 L6130

L6131

L6132

1-1

Plan 2.3. Burial Cave T12.

Fig. 2.6. Cave T12, the sealed entrance from inside.

5 00

4 00

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

21

Fig. 2.7. Cave T12, the entrance chamber and the sealed entrance.

Limestone sarcophagi were found in three loculi (Figs. 2.8, 2.9): L6128 (0.55 × 2.10 m, 0.50 m high, wall thickness c. 10 cm), L6130 (0.4 × 1.3 m, c. 0.3 m high, wall thickness 5–7 cm) and L6131 (similar in size to the sarcophagus in L6128). The sarcophagi are made of soft limestone in a style reminiscent of Samaritan sarcophagi (second–fourth centuries CE; Eitan 1969:62, Pl. XII:1–3; Barkay 1987; Magen 2009:293–351). The sarcophagi in Loculi 6128 and 6131 have gabled limestone lids; one was broken and the other had been moved during looting in antiquity. The lid in Loculus 6128 has acroteria-decorated corners. By order of the Israel Antiquities Authority, no archaeological excavation was conducted and the sarcophagi were left in situ. As the cave could not have been used after the dam and reservoir were created, this resulted in the loss of a potential terminus post quem for the construction of the dam and the Low-Level Aqueduct to Caesarea.

22

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 2.8. Cave T12, Loculi 6127–6129; sarcophagus with broken lid in L6128.

Fig. 2.9. Cave T12, Loculi 6130 and 6131 with sarcophagi.

Remains of Quarrying (Burial Cave?) in Channel 1 (Plan 2.4) In the rock surface at the eastern end of Channel 1 (C1), which conveyed water from the distribution basin to the flour mills (see Chapters 3, 4), are quarrying remains (L2334) that resemble the beginning of a barrel vault on the western wall, while the vertical eastern wall was preserved to a height of 1.8 m (5.17 m asl). The floor of the vault is at 3.37 m asl (Plan 2.4: Section 1-1). Triangular niches carved into the eastern and western walls of the channel (L6200, L6201; both 0.23 m wide at the base, 0.30 m high, elevation at the base 3.97 m asl) resemble the lamp niches in Burial Cave T10; apparently, L2334 represents the remains of a burial cave that existed here prior to the hewing of Channel 1.

23

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

Farther to the west, in the northern wall of Channel 1, two niches (L6202, L6203) were discerned below and above a rectangular opening (L46) through which water flowed into the Low-Level Aqueduct in its original phase (see Phase IVb, below). Very little of the lower niche (L6202) was left after L46 was hewn (Plan 2.4: Section 1-1),

89

33

4 95 4 56

28

1

L2334 5 17

3 97

3 92

5 45

4 20

39

3 37 5 01

4 37

3 77

L46 1

4 67

2

39 87 86

C1

11 18

08

2

67

2352

37

0

2

m

Burial cave remains L6200

L6203

6 00

6 00

L2352

5 00

5 00

4 00

4 00

L6201 L6202 L46

L2334 1-1

3 00

2-2

Plan 2.4. Remains of a presumed burial cave (L2334) in Channel 1.

3 00

24

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

and only the upper part of the upper niche remains (0.10 × 0.53 m, preserved height 0.15 m). On the opposite side, in the southern wall of Channel 1, two niches (0.33 × 0.55 m, 6–10 cm deep) were discovered east of L2352 (the northern section of the LowLevel Aqueduct; Plan 2.4: Section 2-2). These niches, located opposite those above and below L46, are similar in size and elevation (the base of the lower niche is 1.1 m from the floor of the channel and the top of the upper niche is 1.8 m above the floor) and retained traces of mortar or plaster. As these two sets of niches were hewn before the rectangular opening (L46) and Channel 1, it is possible that a vaulted burial chamber with hewn niches was destroyed when the distribution basin and L2352 of the LowLevel Aqueduct were hewn.

The Lower Aqueduct and the Paved Road Beside and Above it Alongside the northernmost exposed section of the Lower Aqueduct (Segment I), remains of a paved road were revealed, which abutted and overlay the walls of the aqueduct. Therefore, in this segment, two phases were defined (Phases Vb and Va). The Lower Aqueduct (Phase Vb; Plan 2.5) A 820 m long section of an aqueduct (termed here the Lower Aqueduct), whose highest floor elevation is over 2 m lower than that of the Low-Level Aqueduct, was surveyed and excavated from the east to the southwest of the Naḥal Tanninim Dam, as far as Jisr ezZarqa. For the present discussion, the Lower Aqueduct is divided into Segments I–VII, from north to south. The northern part of the Lower Aqueduct, within the area of the Naḥal Tanninim Reservoir (Segments I–III), was covered by a layer of clay soil (up to c. 4 m asl) that had accumulated in the reservoir, and therefore no traces of the Lower Aqueduct or the paved road alongside it were visible on the surface. The northern stonebuilt section of the Lower Aqueduct (Segment I) was erected on the soil of the river valley, while most of its course was hewn into the kurkar ridge (Segments II–VII). The Lower Aqueduct was exposed along a continuous section approximately 400 m long, from the southern bank of Naḥal ‘Ada (map ref. 19241/71720; Sq Z/86) to approximately 45 m south of the point where it branches away from the course of the Low-Level Aqueduct (Segment VI; map ref. 19221/71689; Sq G/55; see below). After a gap of c. 190 m, what appears to be the continuation of the Lower Aqueduct was detected west of the LowLevel Aqueduct (Channel 432; Segment VII) and surveyed for another 230 m in the kurkar bedrock until it disappeared under the modern dumps of Jisr ez-Zarqa (map ref. 19213/71683–19201/71664). The Built Section (Segment I; Plan 2.6) A section of a wall founded on the clay soil of the river valley was exposed (Figs. 2.10, 2.11); however, its northward extension continued under the accumulated fill in the reservoir. The wall narrows gradually toward the south in three parts (from north to south):

25

92

ann al T

192 400

192 350

h.

Na

M15

90

m

ini

M16

717 91 250

192 300

192 200

192 250

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

717 250

L461

89

Nahal . ‘Ada

88 M14

87 717 86 200

Lower Aqueduct

85

I

717 200

84 83 Dam

82 717 81 150

80

II 717 150

M12

79 Built flour mills

78 77

74 Channel 1

72

III

Q9 Low-Level Aqueduct

75 73

Diversion channel

M10

M13

Hewn flour mills

717 76 100

Sluice

M11

Q6

Q4

Q5

717

Lower Aqueduct 100

P5 Q1

717 71 050

69

717 050

Q2

Lower Aqueduct

70

Low-Level Aqueduct

IV

68 67 717 66 000

717 000

65

64 43

V

63

42

62 Lower Aqueduct 716 61 950 60

41

Low-Level Aqueduct

59

39 L432

58

38

57

37 VI

716 56 900 55

716 950

40

VII

36

716 900

35 34 L� M� N� O� P� Q� R�

54 53

0

J

K

L M N O

P

Q

R

S

T

U

192 350

I

192 300

H

192 250

F G

192 200

716 E 850

V W X

50 m

Y

Z AA BB 716

192 400

52

Plan 2.5. General plan of the dam, the Low-Level Aqueduct and the Lower Aqueduct.

850

26

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

1 2 40

W453

2 57

2 32

W452

2 30

L412

2 29

1 68 1 44

W459

L426 1 65

W451

2 46

L425

L413

2 33

L411

2 43 2 78

2 87

L409

L414

W407

1

2 62

2 78

2 87

2 69

W406

2 83

2 95

3 01

3 08

2 58

2 96

3 24 3 33

3 46

L401 0

2

m 3 00 L411

L413 Pier 452

W459

L412

Pier 451

W407

2 00

1 00 1-1

Plan 2.6. Lower Aqueduct Segment I: built section to the beginning of Channel 401, and the paved road to the west (L409).

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

W406 L409

Fig. 2.10. The Lower Aqueduct, general view of the built section and the paved road to its west, looking north.

W407

L409

Fig. 2.11. The Lower Aqueduct, close-up of the paved road (L409), looking east.

27

28

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L411

L412 W452

W451

W407

L425

L426

Fig. 2.12. The Lower Aqueduct, the piers, looking east.

1. Foundation W459 (c. 2.6 m wide, max. elevation at top 1.68 m asl) supports Piers 453, 452 and 451 (1.82 × 2.20 m)1 between which spanned arches 413, 412 and 411, each 2 m long (Fig. 2.12). Only the two upper courses of the eastern face of W459 were revealed,2 protruding 0.4 m from the eastern faces of Piers 452 and 451, and it is reasonable to assume that its western face extended for a similar distance from the piers. 2. Foundation W459 transitions into a narrower wall (W407) that extends southward for 10.10 m. The width of W407 is the same as that of the piers (1.82 m). The top was destroyed, and it is preserved to an elevation of 2.65 m asl in the north and 2.83 m asl in the south. 3. Wall 407 transitions into W406, which is narrower by c. 0.2 m on either side (1.46 m wide) and extends for 7.10 m to abut the natural kurkar in the south where Channel 401 was hewn (Fig. 2.13; see below). Wall 406 is preserved to its full height (3.33 m asl) before reaching Channel 401, whose floor is at 3.30 m asl near the point where they meet. The piers above W459, W407 and W406 were built of two rows of ashlars laid as headers and stretchers in no fixed order and bonded together with gray mortar, with a core of stones and gray mortar between them (Porath 2002a: Type 2). The two courses that were exposed of the eastern face of Foundation W459 were built solely of headers. The preserved upper courses of Piers 453, 452 and 451 (2.40 m, 2.32 m, 2.46 m asl, respectively) incorporated springer stones (lowest elevation c. 2.30 m asl at the northern end of W407) of arches with a radius of 1 m (i.e., half the span between piers; Plan 2.6:

1 2

Only the southern part of Pier 453 was exposed in the excavation, 5.9 m from the southern end of W459. Due to the high groundwater, the excavation only reached a depth of 0.45 m below the top of W459.

29

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

Section 1-1). Assuming that the thickness of the stone arch was 0.3 m, then the top would have reached 3.4 m asl, similar to the elevation of Channel 401. From these observations, it follows that the built section in Segment I is the southern part of a wall that was designed to carry the aqueduct at an elevation of approximately 3.35 m asl, and the gradual reduction in width of the wall to the south indicates that it supported a higher structure in the north. Assuming that the water channel at the top of the built wall was 0.5 m wide, like that of Channel 401, then the width of each side wall would have been about 0.4 m. As noted, the maximum elevation of the preserved built section increased southward, sloping upward as it became more distant from the course of Naḥal ‘Ada and approached the kurkar ridge (from 2.40 m asl at Pier 453 to 3.33 m asl at the southern end of W406). The foundation of the built section also became shallower as it continued southward from Naḥal ‘Ada. The use of interlacing arches is consistent with the method of building aqueducts in the interface between low and high topography, as with the High-Level Aqueduct to Caesarea. When the difference between the floor of the aqueduct and the local topography was 1.5 m or more, the aqueduct would be supported by such an arched wall, whereas a more moderate interface could be borne by a continuous solid wall (Porath 2002b:106).

Segment II (Plan 2.7). Hewn Channel 401 (0.50 × 4.30 m, floor elevation 3.30 m asl in north and 3.24 m asl in south) terminates in the south in a hewn basin (L402). Its walls are preserved to a height of 0.34 m near the basin (Figs. 2.13, 2.14). No remains of built walls of the channel were discerned above the kurkar rock, nor

W406

3 24

L409

3 33

2 58

2 96 3 30

3 46 3 88

L401 3 24

8

3 70

W 41

The Hewn Section (Segments II–VII; Plans 2.7–2.11) Most of the exposed course of the Lower Aqueduct consists of a channel hewn in the kurkar ridge. The northernmost segment (II) of the hewn channel, from the point where W406 abuts the exposed kurkar (see above) to Basin 402, is designated L401. From the basin it continues southward as L403 for approximately 305 m (Segments III–V) until the point where the hewing was not completed. From there it was exposed for c. 45 m (Segment VI; L431; see below). After a gap of 190 m, the continuation was surveyed for another 230 m after cleaning of the kurkar bedrock surface (Segment VII).

1

3 21

L404

L402

3 93

1

L403 3 27

0

L403

L402

2 m

4 00

L402 1-1

3 00

Plan 2.7. Lower Aqueduct Segment II: Channel 401, Basin 402 and the northern end of Channel 403.

30

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

was there plaster on the floor or walls, or in the fill in Fissure 404. Road 409 (see below) abuts the natural kurkar slope west of L401, and the road’s eastern curbstones (W418) lie on Basin 402 and render it obsolete. Channel 401 enters the hewn quadrangular basin (L402; max. dimensions 2.9 × 3.1 m, floor 3.21–3.26 m asl) in the center of its northern wall. The walls of the basin are preserved to 0.72 m above the floor (Figs. 2.13, 2.14). Channel 403 exits from the center of its southern wall. The floor elevation of Basin 402 resembles that of the hewn channels to its north and south and the presumed elevation of the built section. Thus, it seems that Basin 402 was planned to serve as a control basin near the transition from the built part to the hewn section, and not as a settling tank. Fissure 404 cuts diagonally across the southeastern part of the basin, with a vertical displacement of approximately 0.1 m and a horizontal displacement of 0.3 m (Fig. 2.14).

L403 L402

L401

W406 L409

Fig. 2.13. The Lower Aqueduct, the meeting point between W406, Channel 401 and Basin 402, looking south.

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

31

L403

04

L4

L402

L401

Fig. 2.14. Basin 402, Fissure 404 and the outlet to Channel 403, looking south.

The displacement along the fissure includes the walls of the basin and therefore occurred after the hewing.3 Segments III–V (Plans 2.8–2.10). Hewn Channel 403 (c. 0.5 wide) continued southward for 305 m as far as Channel 431, which was not completed (Figs. 2.15–2.18). The floor of L403 does not slope uniformly: it rises from 3.27 m asl at the outlet from Basin 402 to 3.68 m asl at a distance of 35 m to the south (Plan 2.8: Section 1-1), then descends gradually to 3.53 m asl near the outlet of the Low-Level Aqueduct from Quarry 2 (see below) and continues at a similar elevation until Channel 431 (3.39 m asl; see Plan 2.11: Section 4-4), whose hewing was not completed. For the water to flow freely without deepening the floor, the water level would have had to be greater than 3.8 m asl, or at least 0.5 m above the floor of Basin 402 (3.27 asl). As the hewing of Channel 403 was unfinished, it is impossible to know if the increase in the floor elevation was a result of an error in measurement, only to be discovered later on, or a failure in execution that could not be overcome by raising the height of the aqueduct’s walls. Whatever the reason, it resulted in the non-completion

Extensive fissuring in the kurkar was discerned on both sides of the dam, although this phenomenon is unknown in the kurkar ridge north and south of the river valley (e.g., no extensive fissures are found in the quarries of Jisr ez-Zarqa, the tunnel in the kurkar ridge for the High-Level Aqueduct, and the kurkar quarries near Ha-Bonim). It was impossible to determine with the means at our disposal, whether the displacement was tectonic or a result of local subsidence of the kurkar. 3

32

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 2.15. Undamaged section of Channel 403, looking west.

of the channel. The guiding elevation must have been the floor of the built section of the aqueduct, as raising its walls would have added considerable weight to the foundations of W406 and the northward continuation, and could have undermined its stability. In places where Channel 403 was hewn to over 1 m below the kurkar surface and had not been damaged by later hewing, the entire section is preserved (Plan 2.8: Section 1-1; Fig. 2.15). The lower part of the channel is rectangular in section, widening from 0.40–0.55 m at floor level to 0.5–0.6 m wide at 0.7 m above the floor. At this point, the wall recedes in a step-like shelf (0.10–0.32 m wide on each side) and continues upward with a slight outward inclination to the top of the rock (depending on the preservation of the kurkar). The step was intended to hold horizontal or gabled roofing slabs, which were typical of aqueducts that provided drinking water (e.g., the High-Level Aqueduct to Caesarea, see Porath 2002b: Figs. 2, 3b–c, 8, 9; the aqueduct from ‘En Ẓur, see Hirschfeld

33

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

3 93

L403 3 27

1

1

4 11

3 61 3 58 4 26

3 68

L403

3 61

5 42 4 28

Q4

3 56

Q6

3 44

3 23

3 61

4 53

6 31

6 28 4 49 3 54

6 48 4 49

5 40 4 29

L403

L403

6 10

3 51 5 98 4 40

5 00

4 50 4 21

L403

L403 3 47

P5

5 25

4 46 3 42

0

20 m

1-1

4 00

3 00

Plan 2.8. Lower Aqueduct Segment III: Channel 403.

2000:243, Figs. 11, 12)4. The roofing slabs were not preserved, either because the work was not completed or because they were later looted. Along a stretch of 130 m (Segments IV, V; Plans 2.9, 2.10), the upper part of Channel 403 was damaged by the hewing of Channel 5509, a segment of the Low-Level Aqueduct to Caesarea (see Chapter 4). The Low-Level Aqueduct is three times wider than the Lower Aqueduct, and its western side cut into Channel 403 and widened its course to 1.7–1.8 m (floor elevation 4.63 m asl where it joined the Lower Aqueduct). The widening was

Aqueducts for drinking water were roofed along their entire length to protect the water quality, while aqueducts for other purposes were roofed principally in places where there was danger of them being blocked by earth or stone collapses or by aeolian sand (e.g., the aqueducts in the Jericho area, see Porath 1985:45–80). 4

34

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

4 50 4 21

L403

L2142

4 98

P5

3 47

4 44

5 83 5 14

5 25

4 46 3 42

1 5 02

L2161 4 74 5 68

4 36 3 53

L403

4 35

L5509

7 32

7 10

1

5 00

7 24

L403

8 00

W5518

L5509 L5509

6 59

0

4 m

L403

7 00 6 00 5 00

W5508 1-1

Plan 2.9. Lower Aqueduct Segment IV: Channel 403 and outlet of Low-Level Aqueduct (P5).

always at the expense of the Lower Aqueduct’s left side wall, so as to reduce unnecessary construction on that side. In some places, work on the Low-Level Aqueduct cut into the step that was prepared for the roofing slabs (primarily on the left side; Plan 2.10: Section 1-1); in other places, the step remained untouched beneath the floor of the Low-Level Aqueduct (Plans 2.10: Section 3-3; 2.11: Section 4-4; Fig. 2.16). Segment VI. The southward continuation of L403, south of the diversion point of the LowLevel Aqueduct from the course of the Lower Aqueduct, was designated Channel 431. Although the work on Channel 431 was never completed, it was possible to follow its course for a length of c. 45 m (Segment VI; Plan 2.11). At the diversion point, the hewing was deepened along the sides of the channel to the approximate level of the floor, but

4 00 3 00

35

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

1

4 21 3 40

L5514

5 74

4 44

6 07

4 99

4 21 3 40

6 43

1

4 99 4 40

5 74

L403 L5509 2 5 46 4 51

2

4 52

W5

517

3 92

4 50 5 36 5 02 5 36 5 15

3

3

4 18 3 56

7 00

L5514

W55

17

4 29 3 59

6 45 5 84

5 00

4 51

4 00 3 00

1-1

5 86

6 00 5 00

L5509 5 59 5 06

4 63

L431

2-2

L5512

4 12 4 15 4 12 5 66

4 00 3 00

6 00

L5509 L403

5 00 4 00

3-3

5 97

0

6 00

10 m

Plan 2.10. Lower Aqueduct Segment V: Channel 403 and Low-Level Aqueduct (L5509).

3 00

36

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

P5

Q2

L5509

L403

Fig. 2.16. Channel 403, opposite the outlet of the Low-Level Aqueduct from Quarry 2 (P5), looking east.

kurkar blocks inside the channel were not detached (Fig. 2.17) and the Lower Aqueduct was blocked off by a built wall (W5513). Continuing southward, only the top of the channel had been hewn along its course, and it had never been completed down to floor level. Wall 436, built of ashlars without any mortar, was preserved up to two courses high along the right (western) side of the unfinished channel hewn in the natural kurkar (Fig. 2.18). Approximately 190 m south of the exposed end of Channel 431 (map ref. 19213/71683–19201/71664), two parallel channels about 4 m apart were surveyed (L432, L5512; see Chapter 4). A sounding was excavated perpendicular to the course of the two channels, down to their floors (map ref. 192023/716713; Plan 2.12). The floor of L432 is at 3.45 m asl, like the southern end of L403, but it is much wider (1.55 m versus 0.45–0.55 m) and the walls of Channel 432 were hewn without a step for roofing stones. In the sounding, the remains of a built wall (W433) crossing Channel 432 were exposed (c. 1.1 m wide,

37

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

6 00

7 00

5 00

6 00

L5509

4 00

W5513

1-1

L5509

L403 5 00

2-2

L403

W5513

6 00

4 63

2

L431

4

L431 5 00

4

3

4 12

5 66

4 15

3

2

4 00

5 59 5 06

1

3 00

L431

3-3

L5512

1

6 00 5 00 4 00

L403

4 70 4 58

3 00

4-4

4 65

5 02 4 09

5 41 3 46

6 43

5 44

W

4 57

0

4

m

Plan 2.11. Lower Aqueduct Segment VI: Diversion of Low-Level Aqueduct (L5509) and Channel 431.

preserved up to 4.4 m asl), built of crudely hewn kurkar stones bonded with a lime-based mortar. These two channels hewn in the western slope of the kurkar ridge have long been known to surveyors (Avraham Izdarechet, the late Yehuda Peleg, Avner Raban and Amnon Kidron, pers. comm.), although they are not mentioned in the archaeological literature, and Channel 432 was commonly presumed to be a failed (or abandoned) course of the LowLevel Aqueduct. No signs of water erosion were discerned on the walls of Channel 432, unlike in Channel 5512 and other channels and conduits of the Naḥal Tanninim Dam (see Chapters 3, 4). This fact seems to indicate that water never flowed in Channel 432, and if the channel was intended as the southern continuation of the Lower Aqueduct, it was never completed.

1

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L4 3

38

W5

51

3

L5 12 L5512

L5509

L403

Fig. 2.17. The Lower Aqueduct (L403) and the Low-Level Aqueduct (L5509) running parallel in foreground, then diverging and continuing as Channels 431 and 5512 (left); note the undetached kurkar blocks in L431 and blocking W5513, looking south.

W

43

6

Fig. 2.18. Southern section of Channel 431 with W436 above the western side, looking south.

39

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

3 09 3 66

4 85

L432

4 64 4 19

6 56

6 14

1 4 81

6 78

5 44

5 31

W4

33

L435 4 09

6 29

W43 4

3 45 3 75

2

2 93

5 95

6 00

4 40 4 70

2

4 60 5 32

L432 L5512 6 25

5 70 6 10 5 93 6 46

6 79 6 60 6 48

6 35

0

W434 6 00

L5512

5 00

L435 L432

4 00 3 00

1-1

5 00

W433 L432

L432

4 00 3 00

2-2

Plan 2.12. Sounding in the southern continuation of the Lower Aqueduct (Channel 432) and the Low-Level Aqueduct (Channel 5512).

2 m

7 08

1

40

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

The Paved Road (Phase Va) Alongside the built section of the Lower Aqueduct excavation in Segment I, part of a road paved with fieldstones and hewn stones in secondary use (L409) was revealed running parallel to the aqueduct. The road is clearly later than the Lower Aqueduct and is therefore attributed to Phase Va (see Plan 2.6; Figs. 2.10–2.12). It is well-preserved in the northern part of Segment I (5.6 m wide, 2.31 m asl). In places, the road’s eastern margins incorporated the preserved top of the built section of the aqueduct (W407, W406) and the spans of Arches 411, 412 and 413, or rested upon a layer of clay soil that separated the paving from W459. Two drainage channels (L425, L426) were incorporated into the pavement and passed through the spans of Arches 411 and 412 (see Plan 2.6). The walls of the drainage channels were made of hewn stones laid lengthwise on their narrow sides (see Fig. 2.12) and their tops had a step-like shelf that was intended to hold covering stones. Road 409 reaches the kurkar ridge in the south and its stones were placed inside the northern end of Channel 401, which was never used. Four aligned stones (W418) arranged upon a layer of clay soil on the western side of Basin 402 (see Plan 2.7) may be the eastern curbstones of the road in this location. In a sounding excavated c. 45 m north of the end of Segment I, a portion of a similar paved road was exposed for a length of 4.3 m (L461; 5.6 m wide; road surface 1.66 m asl; see Plans 2.5, 2.13; Fig. 2.19). From the quality of construction, the orientation and the width, it appears to be a northern extension of Paved Road 409. Owing to time limitations and high groundwater levels, the excavation was unable to ascertain whether this section of paving was laid upon or alongside a northern continuation of the Lower Aqueduct.

1 66

L461

0

Plan 2.13. Sounding in the northern continuation of Paved Road 409, north of Naḥal ‘Ada (L461).

2

m

CHAPTER 2: THE PRE-DAM STRATUM (STRATUM V)

41

Fig. 2.19. Road 461, looking west.

Summary The scale and architectural quality of the Lower Aqueduct, and the preparations for roofing along the hewn section of the channel (L403), attest that this was a project to supply drinking water to a nearby city, rather than irrigate fields. This aqueduct was apparently intended to convey water from springs in the Naḥal Tanninim Valley west of the Carmel Ridge, at an elevation of 3.0–3.5 m asl (probably the Timsah Springs; see Chapter 1: Fig. 1.2), to a rich urban community. The most reasonable candidate for such an ambitious project, although it was never completed, is the Herodian city Caesarea Maritima. Another, less likely candidate, is Straton’s Tower, which predates Caesarea.5 The northward continuation of the Lower Aqueduct, north of Naḥal ‘Ada, is doubtless located under the sediments of the Naḥal Tanninim Reservoir, beside or beneath Paved Road 461. The unfinished southward continuation of the hewn channel is lost beneath the debris of the modern town of Jisr ez-Zarqa, and no continuation of the aqueduct has been found to the west of the kurkar ridge, between Jisr ez-Zarqa and Caesarea.

Due to the scanty evidence currently available, one cannot rule out the possibility that the unfinished Lower Aqueduct was initiated by a ruler of Straton’s Tower in the late second century BCE, such as Zoilus. 5

42

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

The excavation of the Lower Aqueduct and the paved road did not yield any diagnostic finds other than a few potsherds dated to the second century CE. On the other hand, the relative chronology of the two hydraulic projects—the Naḥal Tanninim Dam and the Lower Aqueduct—is unequivocal: a. The Lower Aqueduct predates the construction of the Naḥal Tanninim Dam and the creation of the reservoir in the fourth century CE (see below). b. The paved road post-dates the Lower Aqueduct and predates the creation of the reservoir. c. A segment of the Low-Level Aqueduct near the Naḥal Tanninim Dam annexed a segment of the neglected Lower Aqueduct (see Chapter 3). Thus, it is evident that the project of the Lower Aqueduct predated the combined project of the Naḥal Tanninim Dam and the Low-Level Aqueduct to Caesarea. The most likely date for the construction of the Lower Aqueduct is somewhere between the second century BCE and the building of the dam in the fourth century CE. The mortar between the stones of the built section of the Lower Aqueduct is of Porath’s Type 2, which was in use from the first century BCE onward (Porath 2002b). The type of mortar supports the hypothesis that the Lower Aqueduct was intended to supply water to Herodian–Roman Caesarea.

Y. Porath, U. ‘Ad and ‘A. a-S. Sa‘id, 2023, Naḥal Tanninim (IAA Reports 71)

Chapter 3

The Nahִal Tanninim Dam (Strata IV–III)

Introduction The Naḥal Tanninim Dam is a gravity dam built across the valley formed by the meeting of the two perennial streams, Naḥal Tanninim and Naḥal ‘Ada, which cuts through the coastal kurkar ridge (see Chapter 1: Fig. 1.2). The dam wall (W204) is 4.80–15.50 m wide and has survived to a length of 193 m and a maximum height of 7.17 m asl (Plan 3.1). This dam, together with the Northern Dam built across the eastern trough, c. 900 m long (Porath, Gendleman and Arnon 2007), created the Naḥal Tanninim Reservoir, an immense, artificial, raised basin covering c. 6000 dunams (600 hectares). The high water level and enormous capacity of the reservoir enabled water to be conveyed to Caesarea via the LowLevel Aqueduct, and the remainder to be used to operate flour mills that were hewn in the western slope of the kurkar ridge to the southwest of the dam (see Chapter 5). As the Naḥal Tanninim Dam blocked the joint outlet of the two streams through the ridge to the sea, it was necessary to first construct a channel to divert the water before work could begin (L31, L34; Phase IVc; Plan 3.2; Fig. 3.1). The diversion channel was hewn in the rock slope to the south of the natural outlet made by the two streams through the kurkar ridge. It was planned so that part of the diversion channel could subsequently serve as a sluice for the dam water (L40; Phase IVb). Farther west, a distribution basin was installed (L48) to control the allocation of water to the different consumers: most of the water was conveyed to Caesarea via the Low-Level Aqueduct (see Chapter 4), while some was channeled to the flour mills (M1–M6) that were installed to the southwest of the dam (see Chapter 5). The dam was constructed in the early Byzantine period (Phase IVb; see Chapter 1). Several localized repairs and modifications were made to the various components of the dam during the Byzantine period (Phase IVa); not all were carried out simultaneously (Subphases IVa5–1). The exposed remains suggest that the number of mills and the amount of water channeled to them increased during the Byzantine period. We interpret this process as reflecting the dam operators’ realization that the quantity of water stored in the reservoir exceeded the capacity of the Low-Level Aqueduct to Caesarea or the city’s consumption. The ‘surplus’ water was thus used to operate flour mills near the dam instead of allowing it to flow unused out of the reservoir’s spillways.

44

T12

95

L6008

94

an lT

M16

7 5313

717 91 250

717 250

M15

90 89

6

88

D5

87

M14

B34

Nahal . 'Ada

B31

717 86 200

84

5

D4

Probe N4

B21

83 Dam

82

4

D6

81

D3

80

M12

79

B10 3

D2

2

M10

77

M1-M6

76 717

B6 B3

Probe W1 Probe E1

Diversion channel

Sluice

Hewn flour mills

717 100

Probe S1

75

Low-Level Aqueduct

74 0

H

I

J

K

L

M

N

O

P

192 300

G

192 250

F

192 200

E

50 m

Plan 3.1. The Naḥal Tanninim Dam.

Q

R

S

T

U

192 350

73 72

717 150

Probe S2

1

D1

M13

Probe N2

B9 B7

M11

78

100

717 200

Nahal . 'Ada southern breach

85

717 150

717 300

h.a

Na

92

m

ni

ni

Probe E7

93

192 350

192 300

192 250

192 200

717 300

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

L31 L34

a

L31

L34

b

Fig. 3.1. The eastern part of the diversion channel (L31, L34), looking west: (a) during excavation; (b) after reconstruction.

45

46

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

This chapter presents the data obtained from the surveys and the 2000–2005 excavations of the Naḥal Tanninim Dam (see Chapter 1). The discussion of this complex hydraulic project is divided into six sections: 1. The diversion channel, built in preparation for the dam’s construction (Phase IVc), parts of which were later used for the sluice and the distribution basin; 2. The construction of the dam wall: the concrete foundation and the upper, exposed wall (Phase IVb); 3. The repairs made to the dam in the Byzantine (Phase IVa) and Ottoman (Phase III) periods, which are described by segments from south to north (1–7); 4. The probes that were inserted into the top of the dam to further examine its construction, and the reasons for the eastward inclination of the water face; 5. The construction (Phase IVb) and modifications of the sluice: passages and distribution basin (sub-phases of Phase IVa).

The Diversion Channel (Phase IVc) (Plan 3.2) Construction of a blocking dam in a perennial river valley is problematic, especially with streams as copious as Naḥal Tanninim and Naḥal ‘Ada. Even today, wherever the archaeological excavations extended deeper than 1.5 m asl, they encountered groundwater, which would also have posed difficulties when the dam was built. The accepted solution in antiquity, as today, was to prepare a diversion channel that would be blocked up when construction was completed. The exposed remains of the Naḥal Tanninim Dam attest to the skill and sophistication of the dam’s planners and their knowledge of the terrain. The diversion channel was hewn in the kurkar ridge on the southern margins of the streams’ outlet, as a significant part of the water stored in the reservoir was to be conveyed by the

L34

1 69

W2 04

L29 L33

L30a-b L36

1 42

6 55

0 71 4 03

1 71

4 56

L49

4 19 4 02

3 51

L42 1 40 L48

L62

5 67

5 08

3 60 5 03

3 92

3 67

P3

4 14

3 92

L28

1 92 4 03

5 49

4 67 6 08

3 37 1 61 3 34

L40 6 18 1 W1 1 51 5 74 P2 2 1 55 1 5 19 L44 6 17 W

L42

L61 3 77

L60 5 63 6 73

L31 2 1 68 W3 L1006 1 55

P1

3 17

4 00 3 40 3 68 4 68 5 39

7 05

1 75

L30c-d

4 80

4 37

4 21

Plan 3.2. Diversion channel in Phase IVc.

0

2 m

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

47

Low-Level Aqueduct southward to Caesarea. This location enabled construction of the dam in the river valley without interrupting the flow of the river, and a long segment of the southern foundation could be built on the natural kurkar bedrock (Probe D1, below). The kurkar bedrock at this point was sufficiently high to allow for the walls of the pre-planned sluice to be hewn into it (preserved to a maximum elevation of 6.08 m asl near the sluice). Thus, the water would pass through the hewn channel without resulting in erosive damage or seeping into the reservoir’s floor or walls. The central part of the hewn channel was designed to subsequently serve as part of the sluice through which water from the reservoir created by the dams could be released (see below). In the east, the hewn channel begins with a north–south segment (L34; 4.3–4.7 × 7.5 m, max. floor elevation 1.69 m asl). Presumably, the northward continuation of the diversion channel was dug into the sediments in the higher parts of the river valley. In the lower parts of the valley, including the river channels themselves, an earthen embankment was presumably laid to the east of the intended line of the dam, to block the natural course of Naḥal Tanninim and Naḥal ‘Ada, and to direct their waters to the diversion channel. The earthen embankment was probably strengthened with organic matter (e.g., branches, grass, etc.) or processed materials (wooden beams, mats, etc.); however, no remnants of these were preserved or discovered in the excavation. At the southern end of L34, the diversion channel veers 95 degrees westward (L31) with a similar width (3.8–4.3 m), widening to 6.8 m in the west to leave space for two partition walls (W11, W12; each 1.3–1.4 m wide; Fig. 3.2) and three passages (P1–P3) of the sluice, without decreasing the capacity of the diversion channel. The walls of L31 and L34 were hewn vertically and no signs were discerned of the detachment of blocks, unlike in the kurkar

W12

W11

Fig. 3.2. The widened part of L31 and partition W11 and W12, looking west.

48

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

quarries (see Chapter 6).1 Part of the northern wall of L31 is missing (L33; c. 4.7 m long) and was later blocked by the construction of W32. The wall was made of dressed kurkar stones arranged as headers and stretchers on the southern face (header length c. 0.90 m, stretcher length 1.10–1.65 m, average height 0.55 m; Fig. 3.3), in line with the wall of L31, while the northern face is irregular and apparently supported an earthen fill to the north. In the rock on the western side of L33, 0.4 m to the north of the southern face of W32, two vertical grooves were hewn, one on top of the other (L30a, b; 0.2–0.3 m wide). In the rock on the eastern side of L33, opposite the bottom of each groove, a rectangular depression was carved (upper, L30c: 0.15 × 0.22 m, 0.20 m deep; lower, L30d: 0.24 × 0.20 m, 0.19 m deep). Apparently, wooden beams were inserted in the depressions on the eastern side and the other ends were placed in the top of the grooves on the western side and pressed down to secure them in place. These two beams probably supported branches or some kind of wicker mats(?) to retain an earthen embankment whose function was to block L33.2 The grooves (L30a–d) were later covered by the stones of W32 and thus precede it, providing evidence of a failed attempt to block L33 with an earthen embankment that was later replaced by a built wall (W32).3

W32

L31

Fig. 3.3. Wall 32, looking north.

It is unclear why there are no signs of block detachment on the walls of the channel, as presumably building blocks were removed here also; the walls may have been intentionally smoothed or eroded by flowing water. 2 It was impossible to determine whether L33 was part of a quarry that preceded the building of the dam (Phase V), as proposed by Yosef Porath, or a failed course of the diversion channel in a north–south direction (like L34), which was too close to the planned dam, as concluded by two of the excavators (Abed a-S. Sa‘id and Uzi ‘Ad). It should be noted that 0.2 m to the south of L31, opposite W32, there are signs of quarrying, which Porath interprets as the southern edge of a quarry that preceded the diversion channel. 3 It is possible that the grooves and depressions (L30a–d) also belong to the quarry of Phase V (see n. 2), as suggested by Porath. 1

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

49

On opposite sides of L31, two vertical grooves were cut (0.25 × 0.25–0.30 m): L29 in the northern wall, c. 5 m from the point where L34 joins L31, and L28 in the southern wall. They were evidently intended to accommodate the wooden boards of a temporary barrier to hold water back before it reached Passages 1 and 2.4 To the west of P1–P3 of the sluice, where the distribution basin was planned (L48; 4.5 m long; see below), the channel narrows from 7.0 m to approximately 4.5 m (floor elevation 1.4–1.5 m asl), and then to c. 4.0 m in the westward continuation of the channel (L49). In some places in L48, the margins of the floor retain a kind of step, up to 1.6 m wide and 0.3– 0.4 m higher than the floor level, and it is unclear if this was created by an enlargement of L48, or by a deepening of most of L48 apart from the step around its edges. The distribution basin was later blocked in the west by W2380 (see below; Plan 3.16), and rock jutting into the northern side of L49 meant that it was narrower in the west (4.3 m wide). The maximum elevation of the diversion channel’s floor to the east of Passages 1–3 (L31, L34) is 1.75 m asl, and the elevation of the thresholds in Passages 1 and 2 is 1.45–1.55 m asl. In the passages and the distribution basin, the floor elevation is c. 1.40 m asl, and the margins of L48 are 1.64–1.78 m asl. In the center of L49, there is a downward step of 1 m (from 1.71 m to 0.71 m asl), after which the diversion channel reverted back to the riverbed. It is possible that L49 originally continued at the same elevation of c. 1.70 m asl, and the step was created when Mill 19 was built (see Chapter 5).

The Dam (Phase IVb) The northern and southern ends of the dam’s wall (W204) are based on the kurkar bedrock, while the central part stands on a concrete foundation inserted into a trench (W208; trench width 10 m, concrete foundation width 6.5–7.0 m; Plans 3.3, 3.4). The two faces of the dam above the foundation are made of large kurkar blocks with a concrete core. At the southern end of the dam is the sluice. The Foundation of the Dam Once the river water had been rerouted into the diversion channel, a foundation trench was dug (c. 7–10 m wide) in preparation for the pouring of the concrete foundations. The sides of the foundation trench could not be discerned in the current excavation, owing to the clay soil and the high groundwater (see below). Probes excavated along the foundations of the water and air faces ascertained that the foundation’s lowest point was deeper on the waterface side than on the air-face side.5 The length of the wooden boards between L28 and L29 exceeded 4.5 m, too wide for a gate to be raised or lowered as a single unit. Thus, it seems that separate wooden boards were inserted between the grooves that functioned as a sort of frame to support a barrier of earth, branches or panels of wicker mats, cloth or leather. It was probably only in use after the dam was finished, during the construction of L47, which transformed part of L48 into a distribution basin (see below). In later periods, the elevation of the reservoir’s water to the east of the dam and Passages 1–3 was higher than the top of the hewn diversion channel, and there was no further need for the barrier. 5 Excavation in Probe D4, along the air face in the center of the dam, attained a depth of over 1.9 m bsl without reaching the bottom of the foundation. 4

50

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

The Water-Face Foundation (Probes B3, B7, B10; Plans 3.3–3.5; Table 3.1) Despite the diversion of the river water, the clay soil on this side apparently remained too water-saturated to enable construction with ashlars or the excavation of a trench with vertical sides that were sufficiently stable to support concrete. Therefore, the foundation trench was wider than the concrete foundation. A wooden caisson was inserted on the eastern side of the foundation trench to serve as a frame into which the concrete foundation (W208) was poured. The top of the caisson was exposed in Probes B3 and B7 (top elevation 0.6–0.7 m asl and 0.9–1.0 m asl respectively).6 Table 3.1. Elevations of the Concrete Water-Face Foundations in Probes Probe

Upper Elevation

Lower Elevation or Bottom of Excavation

Notes

Plans

B3

0.9 m asl

Not reached

Preserved caisson L210

Plan 3.3

B7

0.6 m asl

>1.1 m bsl

Preserved caisson

Plan 3.4

B10

0.27 m bsl

>1.31 m bsl (reached groundwater)

Six stone steps on water face

Plan 3.5

The caisson exposed in Probe B3 (L210; Plan 3.3) was made of carefully joined, sawn and planed wooden boards (5–7 × 5–25 cm, over 1.2 m long; Figs. 3.4, 3.5) that were placed vertically and fixed together with horizontal beams (15 × 15 cm, over 2 m long) and iron nails. The precise fit of the caisson’s components reveals that they were first prepared outside the trench and then fixed in place with partially worked wooden posts set 2 m apart. Laboratory analysis of the wood (see Chapter 13) indicates that the boards, beams and posts were cut from trees that grew in the vicinity, such as Syrian ash and elm, as well as Aleppo pine that was probably imported. The concrete foundation (W208) was a mixture of gray lime-based mortar and stones (rubble, fieldstones and dressed stones). In Probe B7, the excavation reached a depth of 1.1 m bsl, but did not reach the bottom of the foundation. The caisson here (L3002; Plan 3.4) was made in a similar fashion to that of Probe B3, but due to the narrow area and the poorer preservation, no samples were taken of its wood. In Probe B10 (Plan 3.5; Fig. 3.6; Table 3.2), north of the breach through the dam from which Mill 12 was fed (see Chapter 5), the excavation revealed six stone steps built as headers protruding from the water face (L3005). Here, the construction of the foundation Table 3.2. Elevations of Features in Probe B10

6

Location (from top to bottom)

Upper Elevation in South

Upper Elevation in North

First step

2.35 m asl

2.33 m asl

Second step

1.93 m asl

1.89 m asl

Third step

1.43 m asl

1.41 m asl

Fourth step

1.01 m asl

1.00 m asl

Fifth step

0.60 m asl

0.59 m asl

Sixth step

0.15 m asl

0.12 m asl

Rounded top of concrete foundation

0.27 m bsl

The wooden caisson was preserved due to the fact that it had been buried in the water-saturated clay soil.

51

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

8 00

8 00

7 00

7 00

6 00

6 00

5 00

5 00

4 00

4 00

3 00

3 00

W204

2 00

2 00

L201

L210

1 00

L210

1 00 W208

L209 0 00

Plan 3.3. Probe B3: view and section of eastern face (including wooden caisson).

Fig. 3.4. The front of the caisson in the foundation of the water face in Probe B3.

0 00

52

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 3.5. View from above of the caisson in Probe B3.

7 00

7 00

6 00

6 00

5 00

5 00

4 00

4 00

3 00

3 00

2 00

L3002

Surface level

2 00

1 00

1 00

0 00

0 00

-1 00

-1 00

-2 00

-2 00

Plan 3.4. Probe B7: view and section of eastern face (including wooden caisson).

53

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

7 00

6 00

5 00

4 00

3 00

2 00

1 00 L3005 0 00

-1 00

Plan 3.5. Probe B10: view and section of eastern face.

Fig. 3.6. The foundation with stone steps in Probe B10, looking south.

54

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

differs from that elsewhere. A fill of clay soil (c. 2.5 m wide) containing small limestone chips had been deposited between the concrete foundation and the natural clay soil of the riverbed. In the interface between the clay soil and this strip of fill, a concentration of plant remains was discerned, perhaps the remnants of reed matting. This strip of fill is apparently evidence of a wide foundation trench that was supported by mats on its margins (at least on the water-face side) before the concrete foundation was poured into the space west of the caisson. The concrete foundation is 0.75 m wider than the block-built water face above it, and the transition is rounded and coated with hydraulic plaster that extends upward to cover the water face. The probe was deepened alongside the vertical concrete foundation to 1.31 m bsl, until groundwater was encountered. The Air-Face Foundation (Probes D1–D6; Plans 3.6–3.9; Table 3.3) In Probe D1, the southernmost probe, the air-face wall was founded on the kurkar bedrock at 0.93 m asl. In Probe D2, the height of the concrete foundation is 1.2 m (0.5 m bsl–0.7 m asl; Plan 3.6; Fig. 3.7). As most of the foundation (up to c. 0.9 m) is coated with plaster that has survived in situ, its construction method and materials could not be identified. The upper part (c. 0.3 m above the plaster) is built of stepped courses of undressed stones, the uppermost course receding 0.5 m from the foundation’s vertical face. The height of the foundation in Probe D3 (Plan 3.7; Fig. 3.8) is 1.2 m (0.6 m bsl–0.6 m asl). The lower part of the air-face side of the wall is made of small to medium-sized, undressed stones (up to 0.15 m long) bonded in lime-based mortar. Above this, three courses of dressed stones were laid in a stepped manner, and a mixture of lime-based mortar and small fieldstones (up to 0.1 m long) is incorporated between the courses. The stones in the lowest course are 0.5–0.6 × 0.4–0.8 m, while those in the two upper courses are 0.2 × 0.2 m. The bottom of the foundation is approximately 1.25 m wider than the lowest course of the exposed upper wall, narrowing by about 0.25 m in its upper part. In Probe D6 (Plan 3.8; Fig. 3.9), the concrete foundation, 0.8 m high (from 0.4 m bsl to 0.4 m asl), is based on a large block of kurkar (bedrock?) that was partially exposed (to 1 m bsl). In Probe D4, excavated near the center of the dam (Plan 3.9; Fig. 3.10), the base of the foundation was inaccessible due to rapidly rising groundwater and safety considerations. Under the exposed upper wall of the dam, four stone-built courses were uncovered (mainly ashlars, some roughly dressed stones; each stone 0.3–0.5 m high), underlain by another Table 3.3. Elevations of the Air-Face Foundations in Probes Probe

Distance from South of Dam

Upper Elevation

Lower Elevation

Notes

D1

5m

0.93 m asl

D2

38 m

0.7 m asl

0.5 m bsl

D3

50 m

0.6 m asl

0.6 m bsl

D6

62 m

0.4 m asl

0.4 m bsl

D4

85 m

0.1 m asl

>1.9 m bsl

Total depth: 2 m

D5

153 m

Not identified

>0.1 m bsl

The juncture of the foundation and the exposed wall is covered with travertine

Air-face wall founded directly on bedrock Covered in plaster

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CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

3 00

3 00

2 00

2 00

1 00

Surface level

1 00

0 00

0 00

-1 00

-1 00

-2 00

-2 00

Plan 3.6. Probe D2: view and section of western face.

Fig. 3.7. The air face in Probe D2, looking east.

56

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

3 00

3 00

2 00

2 00

1 00

Surface level

1 00

0 00

0 00

-1 00

-1 00

Plan 3.7. Probe D3: view and section of western face.

Fig. 3.8. The air face in Probe D3, looking east.

57

8 00

8 00

7 00

7 00

6 00

6 00

5 00

5 00

4 00

4 00

3 00

3 00

2 00

Surface level

2 00

1 00

1 00

0 00

0 00

-1 00

-1 00

Plan 3.8. Probe D6: view and section of western face.

Fig. 3.9. The air face in Probe D6, looking east.

58

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

3 00

3 00

2 00

2 00

1 00

Surface level

1 00

0 00

0 00

-1 00

-1 00

-2 00

-2 00

-3 00

-3 00

Plan 3.9. Probe D4: view and section of western face.

Fig. 3.10. The air face in Probe D4, looking east.

59

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

course of roughly dressed stones (0.6–0.7 m high, 1.9 m bsl at its base). Remains of limebased mortar or plaster were exposed on the outer face of the foundation to an elevation of 0.1 m asl. A thick layer of travertine (up to 0.3 m thick) was deposited here on the air face of the dam, from 0.4 m bsl and above. The lowest travertine line attests roughly to the surface level on the air-face side after the dam was built. Probe D5, in the northern part of the dam (Plan 3.10), reached a depth of nearly 0.1 m bsl. The exposed foundation is built of ashlars on a moderate incline. A thick travertine deposit, from 0.25 m asl and above, attests roughly to the surface level on the air-face side after the dam was built. 4 00

4 00

3 00

3 00

2 00

2 00

1 00

1 00

0 00

0 00

-1 00

-1 00

Plan 3.10. Probe D5: view and section of western face.

Comparison of the Two Faces The probes on opposite sides of the dam illustrate the differences in depths and construction methods between the two faces. The foundation of the dam’s air-face side was laid at a higher elevation than that of the water-face side. The lower part of the dam’s foundation, as revealed in the excavation, was made of concrete that carried the stone courses of the upper wall. Between the concrete foundation and the exposed part of the air face wall were transition courses of both fieldstones and dressed stones cemented with lime-based mortar. The concrete foundation of the water face extended deeper to prevent water from seeping underneath it and potentially damaging the dam’s stability. In Probe D2 on the air-face side, the foundation extends to 0.5 m bsl, while in Probe B7 on the water-face side, the excavation reached a depth of 1 m bsl without reaching the bottom of the wooden caisson in which the concrete foundation was cast. The upper foundation in Probe D2 was built of stepped courses of undressed stones consolidated with lime-based mortar and the lower part was covered with lime plaster. Problems of groundwater and soil slumping on the eastern side of the foundation trench were solved by casting the concrete foundations in wooden caissons and supporting the side of the foundation trench with reed mats or similar material.

60

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

The Exposed Upper Wall of the Dam Wall 204, the superstructure of the dam above the foundation, is built of two faces of large kurkar blocks with a concrete core. The air face is stepped, with each course receding by 5–35 cm, while the water face is nearly vertical. Both faces were apparently coated with hydraulic plaster. The Water-Face Wall The water-face wall above the concrete foundation was constructed of large kurkar ashlars laid as headers and stretchers in no particular order. Today, the middle and northern sections of the wall incline eastward.7 The wall is covered with two layers of hydraulic plaster: the inner layer is gray and the outer is pinkish (Porath 2002b:25, Type II, 2–3). Wherever the transition from the concrete foundation to the ashlar-constructed upper wall was exposed (L210, L3002, the ‘steps’ in Probe B10; see Plans 3.3–3.5), the built wall’s face receded westward 0.7–0.9 m from the eastern face of the concrete foundation. As noted above, six stone steps made of protruding headers were exposed in Probe B10 (see Plan 3.5; Figs. 3.6, 3.11). The tread of the lowest step is 0.42 m above the rounded top of the concrete foundation. The steps, the water face and the top of the concrete foundation are coated in hydraulic plaster. The treads of the steps incline slightly downward on the northern side (see Table 3.2) and it is unclear if they were originally built in this way or if the slant is associated with the general slumping of the dam’s courses

Fig. 3.11. The steps on the water face in Probe B10, looking west.

7

On the question of whether the inclination was originally planned or occurred later, see below.

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

61

toward the center (see below). The steps have no structural value, and perhaps facilitated ascent during construction. The Air-Face Wall The air-face wall was built principally of stepped courses of kurkar ashlars, with the lower part of the wall wider than the upper part. In most places where the bottom of the lowest ashlar course was exposed (0.4–0.5 m asl), it is flush with the western face of the concrete foundation, with the exception of Probe D2 where the wall recedes 0.5 m. In general, there is an eastward recession of 5–35 cm between each additional course (see Plan 3. 8). In Probes D4 and D5, the external stone face above the foundation inclines eastward (see Plans 3.9, 3.10). Two methods of construction are discernible in the original air face (Phase IVb): (a) courses of large kurkar ashlars (0.4–0.6 × 1.0–2.2 m, 0.5–0.7 m high; e.g., Plan 3.8) laid as headers and stretchers in no fixed order, the stones staggered to ensure that there were no shared vertical joints in successive courses; (b) courses of smaller kurkar stones (0.30–0.40 × 0.25–1.00 m, 0.30–0.40 m high), some dressed so that the outer face is slightly rounded, the courses not meticulously staggered so that continuous vertical joints occasionally occur (Fig. 3.8). The two methods used gray, lime-based mortar between the courses. The air-face side was evidently coated in hydraulic plaster to its full height, although the plaster was only preserved on the foundation. The Dam’s Core The core between the two faces of kurkar stones was revealed in the modern breach for Naḥal ‘Ada through the dam from 1.2 m asl to the top (see Plan 3.1).8 It is composed of gray, lime-based mortar with randomly placed stones of various sizes, from fist-sized up to the size of the facing ashlars (see above). Most of the stones are kurkar, a few are limestone, and most are uncut, with a few dressed stones in secondary use. Horizontal layers detected in the concrete core are identical in height to the outer courses, indicating that the construction was done according to course: first, courses of stones were laid on each face, then the concrete was poured into the core, continuing in this way until the dam was completed. In the upper 1.5 m of the core, beneath the current top of the dam, the stones retained traces of mortar but were also interspersed with a black soil of unknown origin. This black soil, at an elevation exceeding 4.5 m asl, could not have come from the clay that had accumulated in the reservoir below. It may be that the mortar between the stones originally contained a large quantity of clayey soil and ash, and after the consolidating lime was washed away following the disintegration of the plaster on the water face, only the soil remained.

The Naḥal ‘Ada breach in the dam was enlarged by the Naḥal Tanninim Drainage Authority in 2000 to provide a solution for flooding caused by extreme rainfall events (the main reason for the Nahal Tanninim Dam project; see Foreword). The work, followed by conservation, was carried out under the direction of Yoram Sa‘ad and Yigal Merom of the IAA Conservation Department. 8

62

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

The Northern and Southern Ends of the Dam Abutting the Bedrock For most of its length, the dam was built on a concrete foundation poured into a wooden caisson placed in a trench dug in the clay soil, while at its northern and southern ends it 3

T12 L6019

L6015 3

L6012

7 53 7 90

1

7 84 7 29

2

W21

7 44

L6008

2 99

5

7 47

L6006

7 29

0 93

50 W2 3 02

0 95

2 34

6 09

16

2 32

L6021

W2

2

2 41

L6005

L6001

2 22

4 03

1

5 94

L6002 M16

04

W2

Nahal Tanninim breach

M15 0

2 m

Plan 3.11. Northern part of the dam (W204, W215), from the Naḥal Tanninim breach to the juncture with bedrock (L6015).

3 83

63

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

rests on solid kurkar bedrock. In the south, the dam wall abuts the kurkar ridge containing the diversion channel and the sluice, where the upper part of the sluice is built of large ashlars upon the leveled bedrock surface. To the south of the sluice, only a small segment of the built dam is preserved. As the local topography is lower today than the top of the dam, some sort of obstacle must have existed here, whether a built wall that was robbed, or some natural rock that was subsequently quarried. At some time prior to the Ottoman period, the dam was breached in a segment extending from the joint between the kurkar bedrock (L6015) and the southern wall of Mill 16, to the modern course of Naḥal Tanninim (Plan 3.1). The vestiges of the two faces of the dam were obscured here by the later Ottoman repairs (W2161; Fig. 3.12) that sealed the breach and allowed the flour mills to operate (see below). At the northern end of the air face, six ashlar courses of W204 abutting the kurkar bedrock remain exposed. They are stepped, each course inset 7–15 cm (Plan 3.11: Section 2-2; Fig. 3.13; W250 was added by the conservators to support the core of W204 [L6008]). In the upper course, the last four stones are in situ; the two courses underneath it have two blocks each and the others have only a single stone. The three upper courses were arranged as headers and stretchers. On the exterior face, the stones are well-dressed and smoothed, but on the inside they are narrower and chipped. The stones abutting the bedrock were laid in shallow foundation trenches cut into the kurkar. Farther down, beneath the remaining six courses, only the foundation trenches survived. Between the stones and on the rock, a gray lime-based mortar is preserved that includes charcoal fragments, potsherds and seashells. Of the original water face, only the two upper courses with one stone in each remain exposed in the northern section, comprising ashlars that were dressed with a vertical face on both sides (Plan 3.11: Section 2-2; Fig. 3.14). The single stone in the lower course is 0.5 × 0.6 m, W216

L6013 W215

7 00

9 00

6 00

8 00

5 00

7 00

4 00

6 00

3 00

L6017

L6015

4 00

2 00

1-1

5 00

3-3 9 00

W215

8 00 7 00

W204

6 00 5 00 4 00 3 00

2-2

Plan 3.11. Sections.

2 00

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

W216 W215

Fig. 3.12. Wall 215, from the juncture with the kurkar bedrock to the outlet of M16 (far left), looking west.

Fig. 3.13. The stones of the air-face wall where it abuts the kurkar rock in the north, looking north.

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M16

W204

Fig. 3.14. The top of the dam wall of the northern segment, looking south.

while that in the upper course is missing the southern part (an intentional break?). In the northward continuation, the tops of the stones of the upper course are exposed along 3.5 m, arranged as headers and stretchers. The northern end of the water face was built into a stepped foundation trench hewn in the rock. The eastern face of the stones was coated with a layer of plaster to which a row of partially dressed stones was later added.

Repairs to the Dam (Phases IVa–III) Numerous repairs and improvements have been made to the dam since it was built. In the current excavations, the dam was divided into seven segments numbered from south to north (see Plan 3.1), in which three types of repairs can be differentiated: 1. Repairs integrated into the original structure, but using smaller stones (0.2 m high, up to 0.4 m long), typical of the late Ottoman period. These repairs were executed from the top of the dam down to 4.7 m asl; for example, in the area of the breach in W204 for the chute to power Mill 10 (see Chapter 5), and at the northern end of the dam, at the juncture with the kurkar bedrock (see below). 2. Reinforcing the sides, mostly the exposed parts, by thickening the original face, but not engaging with it. Occasionally, this was done with blocks from the original dam; for example, the water face in Segment 1 (see below), but most often with smaller stones, typical of the Ottoman period, as in Segments 5 and 7 (see below). 3. During the Ottoman period, repairs were carried out along the top of the dam, in places where the top courses had been depleted by stone robbing. For example, in Segment 1

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

(Probes S1, E1, W1; see Plan 3.12), pits were filled with small pieces of gray rubble. In Segments 2 and 4 (Probes N2, N4; see Plan 3.1), two methods were discerned: a filling of crushed and well-packed kurkar, which was covered by gray, lime-based mortar rich in ash, charcoal and crushed shells, and then small stones or stone paving; or a filling of alternating layers of crushed kurkar, and brown soil mixed with stones. Segment 1 (Plan 3.12) The foundation of this segment, which extends from the sluice to Probe B3 (c. 17.5 long) is 15.5 m wide, almost double the usual width of the dam. It seems that the thickening of the air face is original, carried out when the dam was built, although the upper part of the southwestern corner was later renovated in the Ottoman period. The thickening of the water face by c. 3 m was added in the Ottoman period (see below).

Mancala board

06

W2

E1 L1015 L1013

1

5 06

6 28

W1 L1016 5 26

1

S1

5 17

L1011 7 11

L1016

0

2

W206

L1013

m

8 00 7 00 6 00 5 00

W204 L1015

4 00 3 00 2 00 1 00

1-1

Plan 3.12. Probes W1, E1 and S1 on the top of Segment 1.

67

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Segment 2 (Plan 3.13) The foundation of this segment, which extends from Probe B3 to Probes B7 and D2 (c. 26 m long), is 7.5 m wide. It seems that the water face was thickened close to the time when the dam was built, while the thickening of the air face (by 1.5 m) was added after the building of Segment 1, but before the thickening of the air face in Segment 3. N2 L1019

2 024 L1018 L1020

6 43

W1

2

L1023

1

L1022 B6

D2 L1023

1 S2

0

2

m

7 00

L1018

6 00

L1022 W1024

L1020

L1023

5 00

4 00 1-1 7 00

6 00

W1024 2-2

5 00 L1022

Plan 3.13. Probes S2 and N2 on the top of Segment 2.

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Segment 3 The foundation of this segment, between Probe D2 and Probe D3 (c. 10 m long), is c. 6.5 m wide. Only the air face above the concrete foundation was reinforced by thickening, after the westerly thickening of Segment 2 and when Segment 4 was already on an incline (see The Inclination of the Dam, below). It is important to note that the juncture between Segments 3 and 4 was well-integrated to create a stronger join at the ‘weak’ spot of the dam, as the eastward inclination of the water face begins in Segment 3. Segment 4 (Plan 3.14) The foundation of this segment, from Probe D3 to Probe B21 (c. 16 m long), is 6.0–6.5 m wide and was not thickened. All eight original courses of the water face have an identical method of construction throughout the length of this segment. The segment is relatively

N4 L1000 L1001

5 52

2

1 L1005

6 60 4 18

L1007 L1008

4 58

1

2

L1007 L1008

0

2 m

7 00

L1001

5 00

7 00

4 00

6 00

L1005

L1005 L1007

6 00

L1002

L1008

L1001 5 00

3 00 L1007 1-1

2 00

L1008

Plan 3.14. Probe N4 on the top of Segment 4.

2-2

4 00

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well preserved, as the six lower courses are preserved along the entire length of the segment and the two upper ones are partially preserved. Segment 5 This segment, from Probe B21 to Probe B34 (65 m long), is 6.5–7.5 m wide. It was thickened on the water-face side, over the original face, apparently in the Ottoman period. The three upper courses of the air face in the center of the segment were built differently, of smaller blocks with intervening gaps. To the north of the part built of small stones, the wall is thicker. Some of the stones protrude from the line of the wall, which appears to be warped to the west. This warping may be evidence of some trauma to the dam—‘shearing’ or a breach—but this cannot be verified as the later reinforcement covers the earlier masonry work. Two breaches were made in this segment of the dam during the Kebara Swamps drainage project in 1924. Segment 6 The foundation of this segment, from Probe B34 to Mill 15 and the modern breach for Naḥal Tanninim (30 m long), is 9.7 m wide. In its southern part, north of Probe D5, the air face was widened by 1.5 m for a length of 10 m. Based on the type of construction and its integration into the masonry work to the south and north, it seems that this thickening was added close to the time when the dam was built. The thickening of the water face was attached to the original face, as in Segment 5, although here using original, large dam stones, and rests on shallow foundations. Segment 7 (see Plan 3.11) This segment extends from the modern breach of Naḥal Tanninim to the dam’s juncture with the kurkar ridge in the north (c. 25 m long). The water face was thickened here in Stratum IV; W215, see Plan 3.11) and its eastern face branches off from the straight course of the dam to reach a maximum width of 10.5 m. Over time, the northern parts of the original dam foundations (W204) and W215 were destroyed, and the destroyed section was filled with variously sized stones that retain traces of lime-based mortar. Most of the construction in this segment, from the southern end of Mill 16 to the kurkar ridge in the north, took place during the Ottoman period. The water-face thickening in Segment 7, W215, began at the Naḥal Tanninim breach and extended in a northeasterly direction. At a distance of 7.5 m from the original water face, it veered northward, extending 15 m in a straight line to meet the kurkar ridge, 10.5 m east of the original dam wall (W204). At a distance of 5 m east of the point where the top of W215 joins the kurkar ridge, the sealed opening to Cave T12 was exposed (see Chapter 2). Some 16.5 m to the north of the modern Naḥal Tanninim breach, a 3 m long section of the water face of W215 was revealed during excavation (L6017; Plan 3.11), laid on a concrete foundation of which only the upper part was exposed (2.65 m asl at top). At a number of points on the water-face side of the concrete, remains of the wooden caissons of the foundation of W215 were preserved (see the dam’s foundations, above). In the middle part of Segment 7, six courses on the water-face side, above the concrete foundation of W215

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

(Plan 3.11:1-1; Fig. 3.12), were built of large ashlars (0.5–0.8 × 0.5 m) laid in alternating courses of headers and stretchers. They are poorly preserved and slant southward. Gaps between the stones reach as much as 0.1 m and some of the original stones are missing (or were replaced). The inclination of the courses and the gaps between the stones may be the result of the wall sinking southward as far as the section where the original wall was destroyed or breached and rebuilt in the Ottoman period, when Mill 16 was built. At the point where W215 meets the kurkar ridge, W215 was inserted into a depression hewn in the rock to create a solid, stable joint (L6015; Plan 3.11: Section 3-3; Fig. 3.15), and then concrete was poured on top of the kurkar rock (upper elevation 4.02 m asl). The water face of W215 is here preserved to a height of three courses. The lowest course is comprised of large ashlars (0.70–0.90 × 0.85 m) and covered with hydraulic plaster and travertine. The accumulation of travertine on the plaster attests that it was exposed to the reservoir water.

W215

L6015

Fig. 3.15. Wall 215 and the groove (L6015) at the juncture with the bedrock, looking west.

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71

The Top of the Dam The top of the dam evidently also served as a bridge over the river valley from the time of its construction. However, the earlier path was destroyed by stone robbery in post-Byzantine periods. During the course of the excavations, eight probes were dug into the top of the dam in order to understand the construction of its upper part in the various phases and the reason for the eastward incline (see Plan 3.1): Probes S1, W1 and E1 in the south, in the widest part of the dam; Probes S2 and N2 at the juncture between Segments 2 and 3; Probe N4 in the center of Segment 4 and Probe E7 in Segment 7, on top of W215, which was found to contain a modern metal water pipe. Probe S1 (Plan 3.12) Probe S1 was dug into the structure at the southwestern corner of the dam wall, from the surface level to the bedrock (L1011; Fig. 3.16), revealing that the structure was evidently built in the Ottoman period. Probes W1 and E1 (Plan 3.12). Probes W1 and E1 in Segment 1 dug through the path on the top of the dam and its underlying fill, both of which date from the Ottoman period. A layer of kurkar stones coated and interspersed with the remains of gray mortar, was exposed to a depth of 1.8 m beneath the top of the dam. Below this is a layer of rubble and dressed stones of various sizes mixed with pale, lime-based mortar and sherds of Ottoman date (L1013, L1016). The upper three courses of the air face in this section postdate the dam’s initial construction. In Probe E1, the original water face of the dam (L1013) was exposed 2.2 m to the west of

Fig. 3.16. Probe S1, L1011, looking south.

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L1013

L1015

Fig. 3.17. Probe E1, the original water-face wall and the Ottoman repair, looking north; note the mancala board game in upper right.

the current water face (W206), which dates from the Ottoman period (Fig. 3.17). The fill (L1015) between the original and Ottoman water faces is composed of a mixture of rubble, dressed stones and lime-based mortar containing Ottoman sherds, similar to the mortar in Probe W1. Hence, prior to the Ottoman period, the water face of Segment 1 continued along the same alignment as that of Segment 2. The eastward addition was built onto the original water face using large ashlars that are similar in size to those of the original water face of Segment 1, apparently in secondary use. The plaster on the original water face of Segment 1, behind the Ottoman-period addition, continues northward in a straight line, into Segment 2. In the northeastern corner of Probe E1, a stone was exposed that contained 17 depressions carved in two rows (Fig. 3.17), which was used for playing Mancala (see Chapter 16). Probes S2 and N2 (Plan 3.13). These two probes in Segment 2 explored the point at which the water face begins its eastward incline from the vertical. Beneath a fill of kurkar stones and crushed kurkar dated by the ceramic fragments to the Ottoman period (L1018), the top of the western part of a wall (W1024; Fig. 3.18) built of large ashlars arranged in headers and stretchers was uncovered c. 1 m east of the current air face. This is evidently the dam’s original air face. To the east of W1024, beneath the later fill (L1018), two layers of partially dressed stones were exposed in most of the area, arranged in a relatively orderly fashion (L1020; Fig. 3.19), similar to L1005 in Probe N4 (see below). As the excavation did not reach any significant depth here, it is difficult to interpret L1020, but it is probably the top of the thickening of

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

L1018 W1024

L1022

L1020

Fig. 3.18. Probe S2, looking south.

L1018

L1020 W1024

L1023

Fig. 3.19. Probe N2, looking north.

73

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

the water-face wall. It is important to note that in these three probes, the walls today incline slightly eastward. The fill (L1022) between the current air face and W1024 (Plan 3.13: Section 1-1) is made of dark gray, lime-based mortar mixed with small stones. In Probe S2, the core of the dam (L1023; Fig. 3.19) was exposed. Numerous cavities between the stones in L1023 are filled with black soil, as observed in the core in the upper part of the section in the Naḥal ‘Ada modern breach (above) and in L1008 in Probe N4 (below), which is apparently due to the flushing of lime from the original mortar mixture. If the eastward inclination of the water face was not deliberate, but the result of gradual slumping, then the building of the new air face was intended to seal the dam and strengthen it in response to this inclination eastward and slumping toward the center. The thickening of the air face continued no farther than Segment 3, after which the inclination was less problematic for the dam’s stability. Probe N4 (Plan 3.14) This probe in Segment 4 was dug approximately 20 m north of the area where the eastward inclination of the water face begins. Below the Ottoman fills (L1001, L1002) are three to four layers of partially dressed stones (L1005; average dimensions 0.25 × 0.35 × 0.70 m; Fig. 3.20) that underlie the Byzantine path and incline eastward at an angle of 6–8 degrees

L1001 L1002 L1005

L1008

Fig. 3.20. Probe N4, looking south.

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75

from the vertical. The stones were laid in an orderly fashion interspersed with gray mortar (similar to L1020 in Probe S2, above). Between the layers of stones in L1005 are thin travertine deposits without any remains of mortar, and beneath the stones in L1005 is a thick travertine layer (L1007; up to 3 cm thick). The travertine attests to the flow of water through the dam, from east to west, between and underneath the layered stones in L1005. Beneath the thick travertine layer (L1007), the original core of the dam (L1008) was exposed. The core comprises partially dressed stones of various sizes bearing traces of mortar and interspersed with a fill of black soil. Therefore, it seems that here too, the original lime binding material was flushed from the mortar leaving only the black soil between the stones. It is important to note that the black soil in Probe N4 lies beneath the layer of travertine (L1007), and this rules out the possibility that the soil penetrated from above, from fill layers deposited on top of the dam when it served as a bridge in the Ottoman period. In Probes S2 and N4, a hewn step was exposed in the exterior side of the upper course of the original air face, perhaps the bottom of a railing (0.4–0.5 m wide; preserved height 0.10–0.15 m; 6.25–6.50 m asl at top)9 from an unidentified period (W1024; Plan 3.13). It should be noted that in a few places where the uppermost stones of later phases were exposed, principally in Segments 2–4, elongated grooves were discerned, perhaps worn by cartwheels. As the stones of the later phases are lower than the estimated elevation of the original dam, due to stone robbery and collapses, they could not be precisely dated. The probes dug into the dam’s core attest to the seepage of water into the dam wall. This is reflected in the layers of travertine between the stone courses (Probe N4) and the flushing of the lime binding from the concrete core (Probes S2, N4, Naḥal ‘Ada modern breach). In places where the stones of the water face incline both eastward and toward the center, the core layers show a similar incline. The excavation did not expose any data as to whether the dam wall was originally designed to incline eastward and slump toward the center, or whether the original structure was vertical and horizontal, and the inclination occurred later. The Inclination and Slumping of the Dam Today, the dam’s water face inclines 6–8 degrees eastward from the vertical, from Segment 3 northward (Fig. 3.21). The stone courses also slump toward the center from the dam ends, which were founded on kurkar bedrock (Fig. 3.22), resulting in the same course being approximately 1.2 m lower at the center of the dam than at its ends. Several explanations have been offered for this phenomenon. In the opinion of marine engineer Ehud Mechrez, the inclination was preplanned. However, the archaeologists Yoseph Porath, Uzi ‘Ad, Abed a-S. Sa‘id and Peter Gendelman all endorse the idea that the force of the water on the foundations, together with the subsidence of the dam in the clay soil on which it was based, were the cause. As the processes of sliding and subsidence of the parts that were based on the clay soil, rather than stable bedrock, were extremely slow, the only cracks in the

This elevation is lower than the maximum preserved top of the original dam (7.17 m asl), but it is possible that the dam’s apparent subsidence toward the center lowered the top of the dam after its construction. 9

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 3.21. The water face inclining eastward, looking north; the protruding stone is the upper step in Probe B10.

Fig. 3.22. Segment II, the slumping of the courses along the water face, relative to the water level of the reconstructed reservoir, looking northwest.

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77

plaster and the dam occurred at the junctures between the two differently based units, and for this reason most of the repairs and thickening of the dam are found near the northern and southern ends (Segments 1, 2, 7). Another factor contributing to the lack of cracking is the relative elasticity of the lime-based mortar construction (core, joints, plaster), which included large amounts of ash and carbonized organic material (Goodman 1998). A third scenario, proposed by Yehoshua Dray, is that the inclination was caused by a tsunami that struck the dam from the west. In the authors’ opinion, there is no evidence to support this suggestion, as the one-time force of a tsunami would have caused multiple cracks in the dam—certainly cracks in the plaster on the water face—and distorted the straight masonry lines.

The Sluice The sluice is an essential part of any man-made water system. Its function is to supply consumers with controlled quantities of water from a source whose capacity is both variable and capable of being collected and stored. The sluice of the Naḥal Tanninim water system was installed in the southern part of the dam because the main consumer in the first phase of its operation (Phase IVb) was the city of Caesarea Maritima, via the LowLevel Aqueduct (see Chapter 4). Controlling the amount of water diverted to the LowLevel Aqueduct was of the utmost importance in order to protect the sides of the aqueduct from uncontrolled excess overflow, and especially to ensure a reliable water supply to the consumers in Caesarea. One of the means of dealing with excess water in the Low-Level Aqueduct was an outlet revealed on the right (western) side of the aqueduct (L5514; see Chapter 4: Plan 4.2), 85 m southwest of the sluice. The First Phase of the Sluice (Phase IVb) (Plan 3.15) As noted above, the sluice of the Naḥal Tanninim water system was built in the middle of the original diversion channel, which was planned in advance for this purpose. The installation includes three passages (P1–P3; 1.6–1.9 m wide near the floor) separated by partition walls (W11, W12; 8.1 m long and 1.4–1.8 m wide at the bottom) and a distribution basin to the west (L48). The lower parts of the partitions were hewn into the kurkar bedrock, as originally planned, while the upper parts were built of large dressed blocks (Plan 3.15: Sections 1-1, 2-2; Figs. 3.23, 3.24). The eastern ends of the partition walls are shaped as an acute angle and the opposite ends in the west are rounded, resembling the pointed prow and rounded stern of a ship.10 The passages between the partitions are 0.2–0.3 m wider at the preserved tops of the partition walls than near the passage thresholds. The flow thresholds

This shape is also known in the piers of bridges, with the pointed end facing upstream. The pointed end is designed to prevent the accumulation of any flotsam that might block the passage between the piers, while the opposite end is rounded to minimize downstream turbulence. It is possible that a column was placed at the top of the rounded end, as on bridges adorned with columns in the Roman Empire, such as the Severan Bridge across the Cendere River in Turkey (Akurgal 1985:347). 10

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 3.23. Aerial view of the reconstructed sluice with water, looking south.

3 86 4 25

1

W2 04

L1004

2 P1

6 55

L2506

1

3 89

5 17

L27

5 17

3 66

1

L42

2

5 01

4 20

W4

1 42

1 75

3 97

L26 3 67

P3

5 19

1 55

L44

3

380

W2

L48

W1

W4

1 43

6 18

2

6 17

L2372 L2378

1 51

P2

1 43

1 40

1 85

7 05

L1006

5 65

L40

1 W1

0 73

1 60

L36

1 42

4 77

0

2

Plan 3.15. The sluice and distribution basin (Strata IV–III).

m

79

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

8 00 W11 W12

7 00 P2

P1

P3

6 00

5 00 L17

4 00

W2514

3 00

L40

2 00

L36

1 00

1-1

W11 P1

P2 W1017

7 00

W12 P3

6 00

5 00 L17

4 00

W2514 W2501

W43 L2506

W2502

2-2

Plan 3.15. Sections.

3 00

2 00

1 00

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 3.24. View toward the passages after reconstruction of the arches, looking west.

Fig. 3.25. Passage 3, W43 in the hewn vault (L42), looking east.

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in the original phase of P1 and P2 (L36, L40) used the floor of the diversion channel that was previously quarried here to an elevation of 1.40–1.60 m asl. The eastern part of P3 (L44), similar in elevation to that of the diversion channel (1.55 m asl), was later blocked by the construction of W41 to an elevation of 3.89 m asl. The western half of the passage was only hewn to an elevation of 3.67 m asl, leaving a 2.20 m high rock step down to the floor of the distribution basin (L48). The eastern edge of a quarried vault (L42) was exposed on the western side of the step, which was blocked by W43 (Fig. 3.25). As W41 and W43 were retained in situ, it was impossible to clarify whether L42 and L44 were connected by a channel through which water flowed in Phase IVc, as in P1 and P2, or whether the rock remained unhewn from the outset, creating a higher flow threshold. The eastern face of W41 was built of large dressed stones; the upper course consists of a single stretcher (0.45 × 0.55 m, 1.45 m long—the width of the outlet), and its exposed face bears marginal dressing with three bosses (Fig. 3.26). The second course consists of two stones, the largest of which (a stretcher?) also bears marginal dressing and two bosses.11 To the west of W41 is concrete composed of limebased mortar and fieldstones. The western face of W43 was built of leveled courses of welldressed stones (0.35–0.55 × 0.50–0.90 m, width unknown) consolidated with lime-based mortar, from which it is evident that W43 was built in dry conditions.12 Fill 2372, which

P3

P2

Fig. 3.26. Passage 3 (left), the eastern face of W41 with marginal dressing on stones, looking west.

The use of stones with marginal dressing is extraordinary in a dam, and the reason is unclear (they may have been found in a quarry that supplied stone for the dam, or perhaps were in secondary use). 12 Construction in water in a dam is done with a concrete cast against a solid side (rock, soil, wall or a wooden caisson) as evident at the base of the dam (see above) and in the walls built to raise the thresholds at the outlets (see below). 11

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

accumulated in the distribution basin and in Passages P1 and P2 after the basin became operational, and before any building was carried out in them (see below), abutted the face of W43; therefore, W43 was built prior to the operation of the sluice or, at the latest, in the first phase of operation (possibly in the first phase of blocking the flow in the diversion channel by placing an obstacle between the vertical grooves (L28, L29; see Plan 3.2). The workers hewing the diversion channel may have encountered the quarry that existed here prior to the building of the dam (Stratum V), or possibly a burial cave, and L42 may have been one of its loculi.13 If there was an ancient burial cave here, then most of the hewn cavity was incorporated into L48 and the eastern part was incorporated into Passage 3 (on the quarrying of the eastern part of Channel 1, which suggests the existence of a nearby burial cave, see Chapter 2). Three pairs of opposing vertical grooves were cut in the walls of each passage, one at the eastern end and two in the west (0.20–0.25 × 0.20–0.25 m). These vertical grooves functioned as tracks for wooden gates that were raised vertically. Horizontal grooves were hewn between the vertical grooves in the floor of each passage to accommodate the gates, one in the east and two, 0.3–0.5 m apart, in the west.14 In the floor of P3, only two horizontal grooves were hewn across the passage, one (L26) in the top of the upper course of W41, running between the eastern pair of vertical grooves (Fig. 3.27), the second (L27) in the top of the stone step above W43, running between the easterly of the two pairs of grooves in the west. The vertical grooves are c. 1.7 m wide in the lower eastern part of P1, and c. 2.0 m wide in the lower eastern part of P2 and P3, widening by c. 0.3 m toward the top. The gates were trapezoidal, tapering toward the bottom to fit the passage dimensions. Their trapezoidal shape made them easy to open and close. The quantity of water flowing through the sluice was controlled by the height to which the gates were raised. During excavation of Passage 2, the lower part of the gate that was inserted in the western vertical grooves was exposed (Plan 3.15: Section 2-2b; Fig. 3.28). The preserved section included three horizontal wooden beams (0.14–0.16 × 0.20–0.23 m, 1.30–1.70 m long), the ends tapering to 5–8 cm (for identification of the wood, see Chapter 13). The tapered ends may indicate that they moved inside a wooden track that was even narrower than the hewn grooves (although no traces of wooden tracks were found). Two vertical wooden beams joined the horizontal beams together with metal nails.15 In each horizontal groove in the threshold of Passage 3, there are two widened parts that were intended to receive the vertical beams, attesting to the fact that at least in this gate, the vertical beams Without dismantling W43, or the partial dismantling of W41, it is impossible to determine if there was a connection between L44 and L48 through the hewn vault (L42), and if W43 was built before water flowed in the diversion channel or when it was transformed into a central part of the diversion channel. 14 The construction of two adjacent gates was a common method used in Israeli fishpond channels until the second half of the twentieth century. The space between the two gates was filled with earth to improve the seal. We thank Arnon Angert of Kibbutz Sedot Yam for bringing this to our attention. It should be noted that the space between the adjacent gates could only be filled when the gates were completely lowered. 15 The wooden gates may have been composed of a number of beams laid one on top of the other, perhaps due to the great weight and bulk of a single gate measuring c. 1.8 × 5.5 m. The part of the gate found in situ in P2 may belong to the lower unit of a gate that did not need to be moved when the passage was opened, which was gradually covered by accumulations (L2372, L2506) and eventually forgotten (see below). 13

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

Fig. 3.27. Passage 3, horizontal groove (L26), looking north.

Fig. 3.28. Passage 2, the lower part of the wooden gate in the west of the passage, looking east.

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

reached the bottom of the gate. Wooden gates of this size (1.8 × 5.5 m) were too heavy to be raised manually, therefore lifting devices that included rod levers and a pulley system must have been used. Mechanisms of this kind have been reconstructed on site by Yehoshua Dray (see Appendix 1) according to traditional methods, and the gates can now be raised by just one person. At the top of the built part of Passages 1–3, the beginnings of vaults were preserved (Plan 3.15), suggesting that the passages were roofed with barrel vaults that provided easier access to the gates’ lifting devices, and also facilitated the use of the dam as a footbridge across Naḥal Tanninim. During the early part of Phase IVa, the water flowed through the gap created between the bottom of the gate and the floor of the passage, not above the gates. In the later part of Phase IVa, the water continued to flow under the gate, although the floors of the distribution basin and the corresponding thresholds of the passages were raised with a lime-based concrete mixed with aggregate (see below). The distribution basin (L48) was created by the construction of W2380 across the wide part of the diversion channel, c. 4.5 m west of the rounded ends of the passage partitions (Fig. 3.29). A tunnel (L47; Plan 3.16: Section 3-3) traversed W2380, and the tunnel’s northern and southern walls (1.35 and 2.55 m wide, respectively) narrowed L48 from 4.50–5.00 m to 1.40–1.45 m. The tunnel was roofed with long kurkar beams (Fig. 3.30).16 Most of the construction above the roofing of L47 was dismantled in the Ottoman period in order to lay Mill 13’s feeder channel (C3), but the remaining vestiges

Fig. 3.29. Wall 2380 and the blocking of Tunnel 47 (note the lead pipe of Drain 2513), looking southwest.

The dressing of the kurkar beams, which were probably quarried nearby, was not completed and there is no sign of plaster coating. 16

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85

L46

W2380

Fig. 3.30. Wall 2380 with a kurkar beam covering L47; at top, Outlet 46 blocked with stones, looking south (see also Fig. 3.31).

imply that the upper part of W2380 remained intact. At the entrance to the tunnel, vertical grooves for a raisable gate were hewn in W2380, adjacent to the eastern face of the kurkar beam (Fig. 3.30). It is reasonable to assume that Tunnel 47 played a role in controlling the flow of water from the distribution basin, apparently to drain off any excess water that had infiltrated into the basin after the passage gates were closed, either through the closed gates or from rising groundwater. In Phase IVb, the water from the distribution basin was channeled solely to the LowLevel Aqueduct through a rectangular outlet (L46) hewn in the southwestern corner of the basin (0.4 × 1.2 m, flow threshold 4.19 m asl; Plans 3.16; 3.17; Fig. 3.31). In Phase IVa it was also channeled to the flour mills through an additional opening (see Chapter 4). Travertine deposits on the walls of the Low-Level Aqueduct near Caesarea attest to the fact that the elevation of the water in it, and in the reservoir, reached at least 6.3 m asl (see Chapter 4). Therefore, L46 was submerged under at least 2 m of water—as were the openings in the passages beneath the adjustable gates. No grooves for a raisable gate were

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L46

Fig. 3.31. Outlet 46, from the distribution basin to the Low-Level Aqueduct, blocked with stones, looking south.

found in the rectangular outlet. Its complete or partial closure could have been achieved by lowering a frame of impermeable material that was fixed to the sides by the force of the water in the basin. Once the dam was completed and the sluice gates lowered, the water in the reservoir was at a sufficiently high level for it to feed the Low-Level Aqueduct via L46. Between the floor of the sluice (L31, L36, L40, L48; c. 1.5 m asl) and the flow threshold of the outlet (4.19 m asl), a space was formed in the distribution basin where the current was slow, trapping debris that accumulated on the floor. However, as the objects that fell or were thrown into the sluice (rocks and garbage, including food waste, complete pottery and glass vessels; see Chapters 8, 9) did not impede the flow, the dam’s operators had no incentive to remove them and they remained on the floor (L1004, L2372, L2378, L2506; Plan 3.16; Fig. 3.32). The finds that accumulated in L2372 and L2506 (see Chapter 8), dated to the fifth–early seventh centuries, were later sealed beneath Pavement 2369 (Plan 3.17: Section 1-1; Fig. 3.32) and the construction in the passages, and thus these alterations can be dated to the sixth–early seventh centuries CE. The lower part of

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87

L2369 9

L2372

Fig. 3.32. Fill 2372 below Pavement 2369 with finds in situ, looking east.

the wooden gate placed in the western grooves of Passage 2 was found in accumulation L2506 (see Plan 3.18: Section 1-1). Finds dating from the fifth–seventh centuries CE (see Chapter 8) were discovered in the lower part of the sluice, to the east of the passages (L1004), overlain by a layer containing finds from the Byzantine to Ottoman periods (L1003), and the distinction between L1004 and L1003 is unclear. Modifications and Additions to the Sluice (Phase IVa) The many modifications made in the initial sluice (Phase IVb) during the Byzantine period can be attributed to sub-phases of Phase IVa. They are more pronounced in the distribution basin than in the passages, and they reveal how the facility’s operators dealt with problems and attempted to use the reservoir water more efficiently. The Passages (Plans 3.16–3.18; Table 3.4). The modifications here in Phase IVa included raising the flow thresholds in Passages 1 and 2 (W2514, W2501; Plan 3.17), followed by the addition of a new passage (P4). The tops of the walls that raised the thresholds in Passages 1 and 2 (L17, L14; Plan 3.18; Figs. 3.33, 3.34) were adapted to correspond with the top of the stone step in Passage 3, above the hewn vault (L42) and the top of W41 to its east (see Plan 3.15: Section 1-1). The construction in Passages 1 and 2 is no higher than the level of the vertical grooves in the east (and in P2 also in the west), indicating that it was carried out when the gates were lowered (Fig. 3.35). The construction in the west of Passage 1 extends c. 0.4 m beyond the vertical grooves of the western gate as far as a barrier made of three horizontal wooden boards (exposed in L2394; 1.93–2.71 m asl) fixed in vertical grooves hewn for this purpose in the passage walls. The lower part of W2514 in Passage 1, up to approximately 3.5 m asl,

88 3 86 4 25 4 77

W2 04

L1004 L36 1 60

5 65

P1

6 55

1 85

1 380 W2

W2512

L42

2

3

1 42

L47

W1

P3

5 19

1 55

2

6 17

L2372 L2378 L48 3

6 18

L44

L26 3 67

89

3 W4

1 43

1 43

1 40

1 51

P2

1 W4

L61

2

5 67

L2506

1 42

L31

7 05

L40

1 W1 4 00

0 73

L1006

1 75

L27

3 66

P4

5 17

5 17

L62 4 20

3 97

1

C2 5 01 3 77

L46

4 67

L2352

4 37

3 60 5 87 4 86

3 39

6 08

C1

3 67

LLA

5 11 4 18

0

3 37

2

m

5 00

4 00

4 00

3 00

3 00 W2380

W2512

2 00 L2513

2 00

W2507

1 00

1 00

1-1

2-2

5 00

4 00

3 00 W2512

2 00 W2380

3-3

W2511

Plan 3.16. The sluice and distribution basin with Tunnel 47 through W2380 (Phases IVb–IVa).

1 00

89

L1003 P1 L1004

204

W

514

W2

L2517 L2519

3 73

5 65 7 05

P2

6 55

1

6 18

18

5 17

5 33

1

5 67

4 03

6 17

3 37

P3

L2365

370 W2 380 W2

4 59

W

L2362

W 25

4 00

1 250

6 19

L2358 L2365 L2348

P4

3 09

4 28

5 49

L2520

5 45

5 17 5 39

3 97 5 01

3 37

45

W

37

W

L46

C1

4 67

3 60 3 77

4 80

5 87 4 37 3 39

L2521

6 08

W2124 5 11 4 18

3 37

0

L2365

2

4 00 L2362

W2370 W2380

3 00

L2369 2 00

L2372

L2378

L48

L2394 1-1

Plan 3.17. The sluice and distribution basin in Phase IVa.

1 00

0 00

m

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

IVb

IVa2 L17

7 05 L2506

P1

L2502

P1

1

P2

W2514

P1

1

P2 6 18

1

1

P3

1

L14

501

P3

W2

1

P3

W4

6 17

1

P2

1

5 19 5 45

5 49

P4

P4

P4

0

4

m

8 00 7 00 6 00

IVa2

5 00

W2501

4 00

W2502

3 00

L2506

2 00

IVb

1 00

1-1

Plan 3.18. The sluice and the blockage in P2 (Phases IVb–IVa2).

Table 3.4. Modifications and Additions to the Passages Phase/Sub-Phase

P1

P2

P3

P4

Plan

III = sluice obsolete

Fill L3

Construction of W1017 on top of W2501

Construction of C3 (L2388)

Canceled

IVa1

Unchanged

Unchanged

Unchanged

Addition of P4, later replaced by P5 (see Chapter 4)

IVa2 = raising of thresholds

Construction of W2514 and, at top, Threshold 17

Construction of W2502 and W2501, at top, Threshold 14 with a depression in the east

Threshold at the top of stone step and W41, with horizontal grooves (L26, L27)

3.18

IVb = original sluice, prior to modifications

Accumulation L2515 (unexcavated)

Orderly laying of stones L2506

Construction of W41 and W43 (end of IVc or beginning of IVb)

3.15; 3.16

IVc = diversion channel, prior to construction of dam

L36

Section L40

Construction of W41 and W43 (end of IVc or beginning of IVb)

3.15

3.17

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

W2501

W2502

Fig. 3.33. The eastern gate in Passage 2 (after the disassembly of W1017 and before the disassembly of W2501), looking west.

W2501

W2502

Fig. 3.34. The construction in Passage 2 (after the disassembly of W1017 and before the disassembly of W2501), looking east.

91

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 3.35. Wooden boards of the eastern gate of Passage 1, looking east.

consists of a mixture of lime-based mortar and rubble that was poured into a wooden caisson inserted into the gate grooves. A few boards of the western caisson remain in situ and the impression of others is discernable in the concrete (Fig. 3.36). It seems that the boards in the western grooves were originally part of the western gate in P1, perhaps the lower unit of the gate (see above). Two courses of dressed stones were placed above the concrete in the wooden caisson, the uppermost of which served as the new flow threshold (L17) in Passage 1 (3.70–3.76 m asl; Plan 3.18).17 In Passage 2 (Plan 3.18), in order to raise the flow threshold, a single stone layer, a sort of pavement, was laid with no intervening lime-based mortar (L2502). Then W2501 was added, built of four courses of dressed stones (2.36–3.90 m asl) bonded with limebased mortar mixed with stones (Sub-Phase IVa2; see Figs. 3.33, 3.34). In the concrete core of W2501, at the level of the bottom course, were the remains of a wooden beam (0.4 × 2.8 m, 0.2 m thick)18 that lay along the central longitudinal axis of Passage 2 (Plan 3.18; Fig. 3.37). The role of this beam is unclear, but it may have served as a stabilizing wedge between the eastern and western wooden gates, in preparation for the construction of W2501. The top of W2501 served as the new flow threshold (L14) in Passage 2 (3.88 m asl), resembling that in Passage 1 (L17). A rectangular depression was hewn into a stone in the eastern part of L14, perhaps in which to fix the vertical beam of the gate (Fig. 3.38). The constructions that raised the flow thresholds in Passages 1 and 2 were not carefully executed, unlike the work in Passage 3. In the east of Passages 1 and 2, the

It should be noted that W2514 remained in situ and it was impossible to determine if the lowest course was only laid on the face of the wall and served as a side support for the concrete, like W41 in the east of Passage 3, or if it was composed of stones for the entire length of the passage, beneath the upper course. 18 The absence of stones to the east and west of the beam’s remains indicates that it originally continued along the entire length of the passage, between the wooden gates in the east and west. The wood species was not identified. 17

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

Fig. 3.36. Remains of three boards of a caisson, one on top of the other, in the west of Passage 1, looking east.

Fig. 3.37. Wooden beam in the bottom of W2501, looking east.

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Fig. 3.38. Rectangular depression in a stone on the eastern side of W2501 (L14), looking east.

structure reached as far as the vertical grooves of the eastern gates (Plan 3.16) and was adapted to a situation in which the eastern wooden gates were lowered to prevent water from flowing through the passages. As noted above, in the west, the structure extends beyond the grooves for the western gates in Passage 1, and more so in Passage 2, indicating that the thresholds of these gates were raised. No additional modifications were made in Passages 1–3. They continued to supply water to the distribution basin until the end of Phase IVa, and were blocked up in Phase III (below). As noted above, the original sluice (Phase IVb) constructed in the early Byzantine period, was intended to control the quantity of water channeled from the reservoir to the city of Caesarea via the Low-Level Aqueduct (flow threshold 5.46 m asl, c. 3 km to the south of the sluice). Surplus water was channeled to operate one or more flour mills via Channel 11 (c. 0.7 m wide) that emerged from the southwestern corner of the distribution basin (flow threshold 3.97 m asl). During the Byzantine period (Phase IVa), allocation of the water was changed, and preference was given to the flour mills (see Chapter 5). In

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95

Phase IVa3 of the distribution basin (see below), Channel 1 was hewn to branch off from the Low-Level Aqueduct to the mills (see Plans 3.16, 3.17). Channel 1 had a flow threshold 2 m lower (3.37 m asl) than that of the aqueduct, creating a situation in which considerable effort had to be invested to continue to provide Caesarea with the same quantity of water. An unsuccessful attempt was made to channel water to the two principal consumers––the city and the mills––with the aid of an auxiliary ‘distribution installation’ (L2521; Plan 3.17; see Chapter 4). The problem was eventually solved by building a new passage in the sluice itself (P4; flow threshold 5.11 m asl), south of Passage 3, and cutting the Low-Level Aqueduct off from Channel 1 with the construction of W2124 (Plan 3.17). Thus, in effect, two sluices were created that operated simultaneously: the original installation (P1–P3 and the distribution basin) for the flour mills via Channel 1, and the new installation, Passage 4, for the Low-Level Aqueduct (see Chapter 4). This situation rendered the distribution basin superfluous. The Distribution Basin (Plans 3.15, 3.16; Table 3.5) The modifications to the distribution basin are more numerous than those in the passages, attesting to continuous efforts to improve control and efficiency of the water flow from the reservoir. As the elevation of the flow thresholds at the entrance to the sluice is lower than that at the outlet to the Low-Level Aqueduct (L46) and the aqueduct’s flow threshold in the area of Caesarea’s modern Aqueduct Beach (5.46 m asl; see Chapter 4), the basin also served as a ‘sediment trap’ where floating debris accumulated, and refuse sank to the floor (L2378; see Plan 3.17: Section 1-1). Five sub-phases of modifications to the distribution basin were discerned here in Phase IVa. Sub-Phase IVa5. The first modification was the construction of W2511 (c. 0.65 m wide) across Tunnel 47 in W2380 (Plan 3.16: Section 3-3). The wall, built of well-dressed stones bonded with gray lime-based mortar, abuts the built sides and roof of the tunnel, and thus was built after the tunnel was completed. Wall 2511 was disassembled in the next phase and only its northern part remained in situ. As the western face of the preserved section is vertical, while the eastern face is irregular, we can surmise that the purpose of the wall was to prevent water from seeping through the gate in the eastern entrance of the tunnel. Grooves for an additional gate in the distribution basin, later replaced by W2511, were hewn at the tunnel’s outlet. The location and quality of construction indicate that W2511 was built when the distribution basin was empty. Vertical grooves (L61, L62) for wooden gates were hewn in the rock sides of the sluice, above the roof of Tunnel 47. The distance between the grooves is too great for a single large gate, and there were probably two gates with a pillar between them that was disassembled prior to the construction of Channel 3 in the Ottoman period (see Chapter 5). The different widths of the grooves (28–30 cm in the north, 18–21 cm in the south) support the suggestion that there were two gates. The operation of one or more flour mills to the west of the distribution basin probably began as early as Phase IVb, as attested by a millstone fragment incorporated in L2513 (see

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Table 3.5. Modifications and Additions to the Distribution Basin Phase/ Sub-Phase

Floor

IVa1

Pavement 2362 abuts the construction in the passages and W2370 (3.30–3.35 m asl)

IVa2

Foundation trench of W2370 cuts L2369, laying of Pavement 2365 that abuts the construction in the passages and W2370 (3.05–3.10 m asl)

IVa3

North Wall

South Wall

West Wall

Plan

Unchanged

Unchanged

3.17

Spillway 2519(?), removal of floor in Spillway 2519 by construction of W2518 to create Spillway 2517

Unchanged

Construction of W2370 adjacent to east face of W2380 + W2507, Pavement 2365 abuts W2370

3.17

Pavement 2369 above L2372 abuts the raised threshold in the passages (2.80–2.85 m asl)

Spillway 2519(?)

Outlet 2520 to C1; Outlet 46 blocked by W45 and C2 by W37

Unchanged (Drain 2513 out of use)

3.17

IVa4

Continued accumulation in L2378, covering the lead pipe of Drain 2513

Unchanged

Unchanged

Blocking of outlet of Tunnel 47 by W2507 in the east and W2512 in the west, disassembling of W2511 (mainly in the south), laying of lead pipe (L2513) and filling of the remaining space in Tunnel 47 (L2510)

3.16

IVa5

Continued accumulation in L2378 and L2372

Unchanged

Unchanged

Construction of W2511 to west of Tunnel 47

3.16

IVb

L48, beginning of accumulation in L2378

Hewn, without outlets

Hewn Outlet 46 to Channel 1 and Low-Level Aqueduct

W2380 with Tunnel 47

3.16

Sub-Phase IVa4; Plan 3.16: Section 1-1). The mill (or mills) was fed by hewn Channel 11 (see above). Sub-Phase IVa4 (Plan 3.16). It appears that W2511 did not solve the problems and was replaced by W2507 (1.4–1.5 m wide), built at the entrance to the tunnel, its eastern face flush with W2380 (Plan 3.16: Section 2-2; Fig. 3.39). Wall 2512 was built at the outlet (Plan 3.16: Section 3-3). Between W2380 and W2512, Tunnel 47 was filled with clay soil (L2510) and rendered obsolete. A drain opening was left in the northern end of W2512 (L2513) to provide drainage for any water that might reach the distribution basin via the closed gates of the passages. The western end of Drain 2513 could probably be closed or opened with either a tap or a valve (for taps and valves in antiquity, see Hodge 1992:322–326). To open up the drain in the west, the southern part of W2511 was destroyed, a fact that dates the fill in Tunnel 47 to the construction of W2511. From the eastern end of Drain 2513, a lead pipe (1.19 m long, 0.14 m diam., 2 mm wall thickness) extended into the distribution basin (Fig. 3.39). The western end of the pipe rested on a fragment of a Pompeian-type millstone, a type found in the mills to the west, attesting that they began operating before Sub-Phase IVa4.

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97

W2507

Fig. 3.39. Wall 2507 blocking entrance to Tunnel 47 in the eastern face of W2380; a lead pipe at the bottom, looking northwest.

It is unclear whether the tunnel cavity (L2510) between W2507 and W2512 was intentionally filled in this phase, or gradually filled with reservoir sediments that filtered through the tunnel’s roofing stones. The clay fill in the tunnel contained a large quantity of melanopsis shells and sand lamellae.19 The accumulation on the floor of the distribution basin (L2378) continued to build up without interruption, even after Tunnel 47 was blocked with fill, covering and blocking the lead pipe at the end of Drain 2513. Sub-Phase IVa3. This sub-phase is characterized by the laying of a stone pavement (L2369; 2.8–2.9 m asl) above L2372 in the distribution basin (Plan 3.17: Section 1-1; see Fig. 3.32). Pavement 2369 abuts the stone sides of the distribution basin and the raised flow thresholds in Passages 1–2, but is cut off from the western wall of the basin (W2380, W2507) by the foundation trench of W2370 from Sub-Phase IVa2 (see below). Sub-Phase IVa3 also probably includes Spillway 2519, hewn in the rock in the northwestern corner of the distribution basin (1.15 m wide, widening to 1.5 m in the north; flow threshold 2.75 m asl), 5–10 cm lower than Pavement 2369. In the sides of L2519, approximately 2 m north of

The significance of this is not immediately obvious, but it is worth noting that lamellae form in standing water that enables the sand to accumulate, as in a pool, and the melanopsis thrive in wet conditions where the water is renewed. 19

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

the basin, vertical grooves (9 cm wide) were cut for a raisable gate. The need for a spillway from the distribution basin, principally in times of maintenance work on the basin and the channels leading from it, was created after Drain 2513 (Plan 3.16: Section 1-1) was blocked by accumulation in L2378.20 The need to pave the distribution basin may have arisen when the diversion of water to the flour mills via Channel 1 (see Chapters 4, 5) gained priority over supplying water to Caesarea via the Low-Level Aqueduct. Outlet 46 was blocked by W45 and replaced with a new window-like outlet (L2520; 0.4–0.7 × 2.1 m, flow threshold 3.38 m asl), hewn in the southern side of the distribution basin, 0.75 m lower than L46. The blocking of Channel 2 by W37 (Plan 3.17) should also be assigned to this sub-phase. Sub-Phase IVa2. In this sub-phase, W2370 (0.55 m wide) was built adjacent to the eastern face of W2380 and W2507, and Pavement 2365 (3.0–3.1 m asl) was laid in the distribution basin above Pavement 2369 (Plan 3.17: Section 1-1). The foundation trench of W2370 cuts into Pavement 2369 and into L2372 as far as the lead pipe to the east of Drain 2513. The new pavement (L2365) abuts the rock sides of the distribution basin, the constructions in Passages 1–3 and the new wall (W2370), and it may have been laid when the Low-Level Aqueduct was disconnected from Passages 1–3, and an alternative channel to the aqueduct was created through Passage 4 in Sub-Phase IVa2 (see Chapter 4). The flow threshold in Spillway 2519 was raised to 2.91 m asl with the construction of W2518 (preserved to a height of two courses), to create a new spillway (L2517) that also has a pair of vertical grooves (9 cm wide) for a raisable gate.21 The bottom of the grooves is at the same elevation as the top of W2518, located 0.65 m to the northwest of the basin’s bedrock side. It is impossible to determine from the remains if the spillway’s flow-threshold elevation was changed in this phase, together with the laying of Pavement L2365, or in the next phase with the laying of Pavement L2362 (see below). The spillway’s threshold could also have been raised irrespective of the laying of these pavements in the distribution basin, during the last sub-phases of Phase IVa. Sub-Phase IVa1. An additional pavement (L2362) was laid in the distribution basin (3.3–3.4 m asl; Plan 3.17: Section 1-1; Fig. 3.40), abutting all its sides. Pavement 2362 represents the final phase in the sluice, when the water flowing through Passages 1–3 was raised to power the flour mills via Channel 1.22

Spillway 2519 may have been hewn slightly later, in Sub-Phase IVa2; see L2517, below. There is a theoretical possibility that Spillway 2517 was installed after W2518 was built in Spillway 2519 and the wall may originally have been higher than its preserved courses. 22 A few Ottoman potsherds were found among the stones of Pavement 2362, but the pavement is not relevant to the system of later flour mills and was apparently damaged when Channel 3 was built in the Ottoman period. 20 21

CHAPTER 3: THE NAḤAL TANNINIM DAM (STRATA IV–III)

99

Fig. 3.40. Pavement 2362 prior to its disassembly, looking west.

Summary As is customary when building a dam across a perennial river, construction of the Naḥal Tanninim dam wall began after the completion of a diversion channel, part of which was hewn in the rock slope to the south of the shared outlet of Naḥal Tanninim and Naḥal ‘Ada in the kurkar ridge. The dam’s construction was planned so that the diversion channel would later serve as the sluice in a water system that would allocate water to three destinations: Caesarea via the Low-Level Aqueduct, the flour mill(s) hewn in the rock west of the dam, and the spillways (L2517, L2519, and other probable spillways not encountered during the excavations), which directed surplus water back to the river course. The fact that the planners chose to locate the sluice along the southern slope of the breach indicates that the conveyance of water to Caesarea was originally the primary purpose of this complex facility. The sluice is exceptionally well-preserved in comparison with those of other dams built in antiquity. The dam comprises a solid wall with two faces of large kurkar blocks and a core of lime-based mortar mixed with stones. At either end, the dam wall was founded on the kurkar bedrock. Between the two ends it was based on a concrete foundation composed of a mixture similar to that of the core; in places the foundation was laid on deep clay soil. To prevent the seepage of water through and beneath the dam, the bottom of the concrete foundation is far deeper on the water-face side. Both faces of the dam, from the foundation upward, were covered with an impermeable layer of lime plaster.

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Apparently at the same time as the Naḥal Tanninim dam was being constructed, the northern dam was erected across the trough to the north, to form the northern wall of the reservoir. Until now, only fragments of a single inscription have been found at the site (L2358, L201; see Chapter 11). The date of construction of the dam, the Low-Level Aqueduct and the hewn mills are not mentioned in any known historical records. From the finds uncovered in the excavation, it may be concluded that the dam was built in the fourth century CE and functioned up to the mid-seventh century (see Chapter 18). The improvements and modifications carried out on the dam over the course of its operation in the Byzantine period, beyond regular maintenance, attest to the shift of emphasis from supplying water to the city of Caesarea to channeling water to the cluster of flour mills west of the dam, and to the fact that the provision of water to the mills and to the Low-Level Aqueduct was separated. The sophisticated water system of the Naḥal Tanninim dam and reservoir fell into disuse following the Muslim conquest and the subsequent decline in the economic and political importance of the coastal region in general, and of Caesarea—the reservoir’s largest consumer—in particular. Operation was renewed in the Ottoman period, with a greatly reduced water level in the reservoir, solely to supply newly erected flour mills along the dam’s air-face side. These mills received water directly from the reservoir without the mediation of the sluice, which was thus rendered obsolete and blocked up. Later additions and repairs made of much smaller stones than the original construction were detected during surveys, mostly along the dam’s air face. These were examined in probes during the subsequent excavations and can be dated to the Ottoman period (see Chapter 5). The most significant repair was the blocking of the pre-Ottoman breach in the northern section of the dam (W216; see Chapter 5), which ensured that the water level in the reservoir remained sufficiently high to enable the mills’ operation. During 1922–1924, the dam was breached in three places in order to drain the Kebara Swamps and free up fertile agricultural land (see Chapter 1; Caron 1922; Ayalon 1987).

Y. Porath, U. ‘Ad and ‘A. a-S. Sa‘id, 2023, Naḥal Tanninim (IAA Reports 71)

Chapter 4

The Low-Level Aqueduct to Caesarea (Stratum IV)

Introduction

193 000

192 000

Dam

719 000

Roa

4 Northern

720 000

d4

5

Road 2

191 000

720 000

194 000

The Naḥal Tanninim Dam was originally constructed as part of a complex water facility designed mainly to convey water to the city of Caesarea Maritima from the abundant springs in the lower basin of Naḥal Tanninim (Figs. 4.1, 4.2). The engineers who planned the project were surely familiar with the failure of the Lower Aqueduct (see Chapter 2). Thus, they decided to raise the stream water by the creation of a huge ‘elevation pool.’

Nahal Tanninim Reservoir

719 000

Ma‘agan Mikha’el 718 000

718 000

Na

h. a l

l h.a

Na

3

‘Ada

717 000

im Tannin

Nahal Tanninim Dam

717 000

716 000

716 000

2 1

km

193 000

1 192 000

191 000

0

715 000

Bet Hananya . 194 000

715 000

1 High-Level Aqueduct

4 Flour mill on Northern Dam

2 Low-Level Aqueduct

5 Aqueduct to Dor

3 Flour mills Fig. 4.1. The Naḥal Tanninim reservoir, and its consumers.

102

718 000

718 000

10

20

Ma‘agan Mikha’el

194 000

193 000

192 000

191 000

190 000

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Jisr ez-Zarqa ‘Awawdy Excavation

2

716 000

10

1

715 000

714 000

‘Ada

Aqueduct Beach

hal Na .

Road 2

20

10

Bet Hananya .

713 000

717 000

1

715 000

714 000

40

716 000

10

Torgë Excavation

20

Nah. al Tanninim

Nahal . Tanninim Dam

717 000

713 000

2

Byzantine Wall

Or ‘Aqiva

712 000

1 High-Level Aqueduct

0

1 194 000

192 000

191 000

190 000

Caesarea Maritima

193 000

712 000

km

2 Low-Level Aqueduct

Fig. 4.2. The Low-Level Aqueduct from the dam to the Byzantine wall of Caesarea.

This was achieved by constructing a dam across the breach of Naḥal Tanninim and Naḥal ‘Ada through the kurkar ridge (see Chapter 3), behind which the stream water accumulated to produce a large reservoir. Based on the topography of the channels of the two streams, this reservoir covered over 6000 dunams (600 hectares). To prevent water from draining northward, a second dam was built across the Carmel trough (the Northern Dam; see Chapter 1; Porath, Gendelman and Arnon 2007). From the reservoir, the water was delivered to Caesarea by way of the Low-Level Aqueduct, whose floor level reached a height of 5.46 m asl. Water sediments on the aqueduct’s walls indicate that the water level inside the aqueduct reached up to 6.30 m asl, which means that a similar water level existed within the reservoir, and that the top of the dam reached at least 6.5 m asl (see Chapter 3). It appears that the reservoir was planned not only to deliver water to the Byzantine city of Caesarea, but also to power several flour mills west of the Naḥal Tanninim Dam and one mill on the Northern Dam (see Chapter 5), as well as to convey water to the city of Dor to the north (Fig. 4.1.; Conder and Kitchener 1882; Peleg 2002b:153–154).

CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

103

The Low-Level Aqueduct Based on its dimensions, the Low-Level Aqueduct was designed to function as the most important water source for the city of Caesarea. Its course, stretching southward from the reservoir, was hewn into the western margins of the coastal kurkar ridge (Fig. 4.3), veering southwest and then south to continue toward Caesarea along the coastal trough, where it became a built channel (Fig. 4.4). Most of the built section in the trough, from Jisr ezZarqa to the Byzantine wall of Caesarea, is today covered by sand dunes. Long segments of the Low-Level Aqueduct were exposed and surveyed by various researchers from the nineteenth century onward, the most important of these being Conder and Kitchener (1882:18), Olami and Peleg (1977:135) and Peleg (1989:121–122). A 335 m long segment of the Low-Level Aqueduct was excavated in the 1960s under the direction of Avraham Negev in the coastal trough north of Caesarea (Negev 1964), now called Aqueduct Beach. Since then, a number of surveys and salvage excavations have been carried out by the IAA and the Combined Caesarea Expeditions (CCE; see Everman 1992) along the course of the aqueduct. Its southernmost known section has been discerned near the distribution installation (castellum divisorium) of the High-Level Aqueduct, inside the Byzantine city (see Chapter 1: Fig. 1.1; Chapter 18; Porath 2006). The channel of the Low-Level Aqueduct averages 1.75 m in width. The lower part of the channel was hewn into the kurkar bedrock wherever the local topography permitted. Its built section is coated with reddish, hydraulic lime plaster on a gray base, while no plaster was discerned in most of its hewn part. The channel has a rectangular section and where

Fig. 4.3. Hewn segment of the Low-Level Aqueduct near the dam, looking north.

104

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

plastered, the angle between the floor and the wall is beveled (a fillet). The channel was roofed with a barrel vault built of fieldstones, ruble and lime mortar to prevent blockage by wind-blown sand and contamination of the water. In places where the vaulted roof is preserved to full height, small holes can be discerned at irregular intervals (from 42 m to

a

b 0

20

Fig. 4.4. (a) Built segment of the Low-Level Aqueduct with vaulted roof, near Aqueduct Beach, looking north; (b) crosssection of the built segment with vaulted roof and beveled joint between floor and sides (drawing after Peleg 1989: Fig. 11).

CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

105

106 m apart; see Everman 1992:186, Fig. 4), which served to equalize the air pressure between the inside and outside of the aqueduct. Four segments of the Low-Level Aqueduct can be distinguished, from north to south: Segment A (Plan 4.1). About 50 m long, from the distribution basin (L2352), via Quarry 1 (L2142; Fig. 4.5) to the point where it joins the course of the Lower Aqueduct (L2161; see Chapter 2). Its course through Quarry 1 was completely built, the rest was hewn. Segment B (Plan 4.2). About 140 m long, a hewn and built segment (L5099) along the shared course with the Lower Aqueduct (L403; Fig. 4.6). Segment C (Plan 4.3). About 4.3 km long, from the point where it detaches from the course of the Lower Aqueduct and continues until the northern city wall of Byzantine Caesarea (including Negev’s excavation in the Aqueduct Beach; see Fig. 4.4). Segment D. About 220 m long, from the city wall to its southernmost known part near the divisorium of the High-Level Aqueduct (see below). An exceptional phenomenon of aqueduct engineering was discerned in the LowLevel Aqueduct: the floor of the aqueduct near the dam is 1.2 m lower than in the area to the north of the Byzantine city wall. The lowest floor elevation of the hewn aqueduct near the dam (Segment A) is 4.20 m asl, rising to 4.78 m asl at 1.3 km to the south of the dam (in Segment C; map ref. 19166/71580). The floor of the aqueduct in the area of Aqueduct Beach (Segment C) then reaches 5.46 m asl––the highest floor elevation in the exposed sections. Farther south, after crossing the northern wall of the Byzantine city (Segment D), the floor elevation is approximately 5.25 m (with deviations of c. 10 cm). We have no explanation for this strange phenomenon of ‘reverse slope’ along approximately half of the Low-Level Aqueduct. A number of possible explanations can be offered: an error in measurement or execution in antiquity, or later tectonic movement. To the best of our knowledge, there were no tectonic episodes that lowered the northern part of the dam relative to the city of Caesarea, and no such movement has been discerned in the High-Level Aqueduct. A cumulative error in measurement seems to be the most logical explanation, as the aqueduct was almost certainly a project that was carried out by several groups simultaneously (see discussion, Chapter 18). At the time of writing, no significant repairs or additions to the Low-Level Aqueduct have been discovered apart from the modifications to the outlets from the reservoir. As Everman notes (1992:184–186), no signs of pumping devices or of built channels for the irrigation of nearby fields have been found. The small air holes on the top of the vaulted roof were too small for drawing water (on the role of Opening 5514, see below). Two main phases were discerned in the Low-Level Aqueduct: the original Byzantine construction phase (Phase IVb), and a phase of modifications made to the outlets from the reservoir, still within the Byzantine period (Phase IVa), which is further divided into SubPhases IVa3–1 (Table 4.1).

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Table 4.1. Correlation between the Phases of the Low-Level Aqueduct (LLA) and the Distribution Basin (DB; see Chapter 3: Table 3.5) Phase/SubPhase of LLA

The Low-Level Aqueduct

Phase/Sub-Phase of DB (see Chapter 3)

Distribution Basin

Plan

III–I

Quarrying and stone robbing

III–I

M19 fed P3; P3 later filled in to serve as infrastructure for C3 that fed Ottomanperiod M13

IVa1

LLA fed via P5; Segment A (L2352, L2142, L2161) blocked off from LLA by W5518

IVa1

Used only for Byzantine mills

3.17; 4.1

IVa2

LLA separated from DB by W2124 and fed via P4

IVa2

Used only for Byzantine mills

3.17; 4.7

IVa3

Outlet 2520 into C1, which cut through L2352

IVa3

Pavement 2369 (or no later than Pavement 2365)

3.17; 4.7

IVb

Original aqueduct with Outlet 46 from distribution basin into L2352

IVb, IVa5–4

Original DB with accumulations in L2372, L2378

3.16; 4.6

IVc

In preparation

IVc

Western end of DB

3.2

V

Ancient quarry

V

Burial cave in southwestern part of basin(?)

2.5

The Original Phase (Phase IVb) (Plans 4.1–4.5) Segment A (Plan 4.1) Segment A of the Low-Level Aqueduct was fed from the distribution basin through a rectangular opening (L46; 0.62 × 1.25 m, flow threshold 4.19 m asl; see Chapter 3) into a channel hewn in the bedrock (L2352; 1.6–1.8 × 1.8 m, floor elevation 4.2–4.5 m asl). From L2352, the water flowed southward through Quarry 1 in a built channel (L2142). Channel 2352 was later damaged when Channel 1 was hewn (see below), whose floor is 0.8–1.1 m lower than the floor of L2352. It is possible that L2352 exploited an earlier rock cutting that may have been a burial cave (see Chapter 2). The course of the channel along the eastern margins of Quarry 1 (L2142) was deeper than the planned floor of the aqueduct; therefore, this section (31 m long) was built on a wide foundation of dressed stones and fieldstones bonded with gray lime mortar (W2160; width 4.1–4.4 m) and covered by a layer of similar lime mortar, 2–3 mm thick (floor elevation 4.35–4.40 m asl; Plan 4.1: Section 1-1; Fig. 4.5). The height of the foundation was adapted to the various levels of the quarrying that preceded its construction. In the north, the foundation consists of two stone courses (0.5–0.75 m total height) laid upon an accumulation of quarry waste. In the south, where the quarrying deepened, the foundation was laid on the bedrock and rises to a height of six to seven courses (1.3–1.6 m). The sides of the channel, preserved to a height of one or two courses (W2103 on the east side, W2136 on the west side), were built on this foundation and a floor was laid between them. As far as possible, the sides of the built channel were adapted to the ancient quarry to minimize construction (mainly on the east side). The floor and the sides of the channel were coated with a layer of reddish hydraulic plaster on a gray base (Porath 2002a: Type II, 2–3), with an average thickness of 4 cm.

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CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

The southward continuation of the aqueduct (L2161; c. 5 m long, floor level 4.33 m asl) cuts through the southern margins of Quarry 1 and joins the hewn course that was prepared for the Lower Aqueduct at a 90° angle (L403; see Chapter 2: Fig. 2.16).

P1 P2 P3 P4

L46

5 11

C1 4 17

L2142

L2149 1

W2103

L2145 W2136

1

Q1

L2352

4 35

W2136

L2140

4 40

L2161

6 00

L2142 W2103 L2145

W2136

5 00

L2105 L2160

4 00

L2149 3 00

1-1

W5518

2

W5508

L403 L5509 0

2

7 00 6 00

L5509 W5518

L403

W5508 L5521 2-2

Plan 4.1. Segment A: the northern part of the Low-Level Aqueduct near the dam.

5 00 4 00 3 00

10 m

108

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L2142

Fig. 4.5. Built segment of the Low-Level Aqueduct in Quarry 1 (L2142), looking northeast.

Segment B (Plans 4.1–4.3) In the transition from Segment A to Segment B, the left side of the Low-Level Aqueduct (W5508) crosses over the Lower Aqueduct (L403), and is curved to improve the water flow (see Chapter 2: Fig. 2.16). Segment B of the Low-Level Aqueduct (L5509; c. 1.8 m wide; 4.4 m asl in the north and 4.63 m asl in the south) thus incorporated L403, which was 0.8–1.0 m lower than it (Plan 4.3: Section 3-3). The hewn right side of L403 now functioned as the right side of the Low-Level Aqueduct (L5509), and long portions of the ledge for the stone cover remained undamaged. A layer of black clayey soil (L5520) beneath W5508 is similar to the soil fill in other parts of the Lower Aqueduct (L403), indicating that L403 was already filled before the wider course of the Low-Level Aqueduct was hewn. The fill in L403 comprised black clayey soil, stone fragments (possibly debris from hewing the left side) and many melanopsis shells (evidence of fresh running water). Due to the absence of finds in this fill, it is impossible to assess how much time passed between the hewing of L403 and its infill, and whether the fill was natural or intentional, immediately prior to the hewing of Segment B (L5509). Above the bedrock on the right side of this segment (max. height 1.95 m above the floor), the sporadic remains of a wall built of rubble and fieldstones in lime-based mortar were discerned (W5517; Plan 4.3: Section 1-1); W5517 continues into Segment C. Where W5517 is preserved to over 6 m asl, the exterior face has a slightly rounded outline (Fig. 4.6), apparently the base of a vaulted roof (see Appendix 1: Fig. App. 1.20). Approximately 46 m from the place where the Low-Level Aqueduct departs Quarry 1, the lower part of an opening was observed (L5514; 3 m wide, threshold 5.74 m asl) in the right side of the channel (Plan 4.2). Vertical grooves were hewn in its jambs into which wooden boards may have been inserted to control the flow of water through the opening. Its threshold is 1.15 m higher than the floor of the Low-Level Aqueduct in this location, but only about 0.3 m above the floor elevation near Caesarea. It seems that opening 5514 was planned as an additional safety valve in days of heavy flooding.

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CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

W5517

L5509

L403

Fig. 4.6. Wall 5517 with the beginning of a vault (arrow), looking northeast.

After the Low-Level Aqueduct fell into disuse, the left side of Segment B was damaged by quarrying to 0.3 m above its floor (Q2). Segment C (Plans 4.3, 4.4) The Low-Level Aqueduct abandons the course of the Lower Aqueduct at the place where the hewing of the Lower Aqueduct was not completed (L431; see Chapter 2: Fig. 2.17) and continues southward along a separate course (L5512). The hewn course of L5512 curves up to the top of the western slope of the kurkar ridge, which minimized construction work on the channel sides, and follows a higher route. Here, Segment C (L5512) was excavated for a length of 125 m, from the point where it branches off eastward until it disappears under sand drifts and debris of modern Jisr ezZarqa (map ref. 19204/71672; see Fig. 4.2). The floor of the hewn channel ranges from 4.63 m asl just before the branching off, to 4.70 m asl at the southern end of the excavated part, and its bedrock sides are 1.0–1.5 m high. There are signs of erosion from flowing water to a height of 6.18 m asl on the right side of the channel. Fragmentary remains of the built superstructure are preserved on top of the bedrock sides, but there are no indications of a vaulted roof. Continuing southward, after an unexplored section of about 100 m long, another short section of the Low-Level Aqueduct was excavated in 2009 (map ref. 192023/716713;

110

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L2142 4 46 3 42 5 02

L2161 L403

4 35

L5509

7 32

7 10

4 74 5 68

4 36 3 53

5 00

Q2 7 24

L403 L5509

1

4 21 3 40

6 59

L5514

5 74

6 07

L403

6 43 4 99

4 21 3 40

1 L5509

4 99

0

10 m

L5514

L5509

6 00

5 00

4 00

L403 3 00

1-1

Plan 4.2. Segment B and Opening 5514.

Plan 4.4; see also Chapter 2: Plan 2.5).1 Two channels were hewn here: one continuing the Low-Level Aqueduct (L5512;) and another (L432) to its west. The two channels were similarly built and of the same width (1.8 m wide). It is unclear if this western channel belongs

1

Carried out as part of the current project, and did not receive a separate permit number.

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CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

74

403

5517 5509

6 00

5509

46 51

5 00 92 4 00

52

551 7

403

3 00

-1

50 36 02 6 00

5513

36 15

1 5 00

5509

1

18 56

4 00

403

7

3 00 4 29 3 59

W551

2-2

6 45 5 84

4 51

6 00 5 86 5 00

L5509 L403

W5513

4 00

3-3

L5509

L403 3

4 63

2

5 59 5 06

W5513

2 5 66

4 12

4

3

6 00

5 00 4 15

L5512 4 00

4-4

4

L5512

L431 0

Plan 4.3. Segment C (L5512) branches away from the Lower Aqueduct (L403).

10 m

112

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

to the Lower Aqueduct or is a mistaken, abandoned course of the Low-Level Aqueduct. At this location, the Low-Level Aqueduct was hewn for most of its height (Plan 4.4: Section 1-1; Figs. 4.7, 4.8). The bedrock on the right side was damaged by later hewing (L435) and is preserved to a maximum height of 2.5 m above the floor (floor elevation 4.60 m asl). The scant remains enable a wide wall built of ashlars with lime-based mortar (c. 2.5 m wide) to

3 09 3 66

4 85

L432

4 19

1 4 81

6 56

6 14 5 31

W4

33

L435 4 09

6 29

4

4 64

6 78

5 44

5 95

6 00

W43

3 45 3 75

2

2 93

4 40 4 70

2

4 60 5 32

L432

L5512

6 25

5 70

6 10 5 93 6 46

6 79 6 60 6 48

6 35

0

W434 6 00

L5512

5 00

L435 L432

4 00 3 00

1-1

5 00

W433 L432

L432

4 00 3 00

2-2

Plan 4.4. Sounding in the southern continuation of Channel 432.

2 m

7 08

1

CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

L432 L435 W433

L5512

Fig. 4.7. The two rock-hewn aqueducts (L5512 and L432), looking south.

L5512

Fig. 4.8. The Low-Level Aqueduct, looking north.

113

114

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

be reconstructed on the right side (W434), in places where the kurkar was missing due to earlier quarrying activities. This is evidence that the hewing activity (L435) occurred prior to the hewing of this part of the Low-Level Aqueduct (L5512). Signs of water erosion on the right side reach a height of 6.4 m asl. Remains of lime plaster are preserved on both the channel sides, and the angle between the floor and the sides is beveled. A layer of dark gray soil (2–3 cm thick) on the rock floor of the channel contained a large quantity of melanopsis shells, evidence of fresh running water. Slightly to the south, the beginning of a vaulted roof is visible at the top of the bedrock on the right side of L5512. To the west of L435, hewn Channel 432 was blocked by a built wall (W433). From the remains in the field, it was impossible to clarify the purpose of this blocking wall, but there may have been an opening in the right-side wall (W434) of the Low-Level Aqueduct to a channel (possibly a spillway) that crossed westward over L432 for unclear purpose (perhaps to irrigate fields or to empty the aqueduct for maintenance). Two salvage excavations were conducted by the IAA in the southward continuation of the Low-Level Aqueduct, west of Jisr ez-Zarqa, in the years following the project discussed here. 1. A section approximately 10 m long was excavated by Hagit Torgë in 2004 on the outskirts of Jisr ez-Zarqa (map ref. 19185–90/71610–30; Plan 4.5; see Figs. 4.2, 4.9; 1

6 10

5 94

L102

5 71

2

4 16

4 19

L5512

L101 4 29 L104

4 26

L103

4 96

5 94

6 10

4 37

2

5 54

5 51 6 75

0

2

1

m

L103 L102

6 00 5 00

L101 L104

4 00 3 00

1-1 L102

L5512

6 00

L101 L104

5 00 4 00 3 00

2-2

Plan 4.5. The Low-Level Aqueduct exposed in Torgë’s excavation (L5512; after Torgë 2006: Fig. 2).

CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

115

Torgë 2006). The lower part of the channel was hewn in the kurkar bedrock, 1.7–1.9 m wide, and above it are the remains of a built wall. The floor is not level (4.16–4.37 m asl). Here too, a layer of dark gray-black soil, rich in melanopsis shells, was exposed upon the rock floor. 2. Another section, 4 m long, was excavated in 2006 by Eiad ‘Awawdy (pers. comm.) at the point where the aqueduct descends from the western kurkar slope and enters the coastal trough (map ref. 19166/71580; see Fig. 4.2). The lower part of the channel in this location (1.8 m wide, floor elevation 4.78 m asl) was hewn in the kurkar bedrock with built sides (0.8 m wide, preserved to 6.08 m asl). The floor and sides of the aqueduct are covered in lime plaster (Porath 2002b: Type II, 2–3) and the joint between them is beveled. The Low-Level Aqueduct continued southward in the coastal trough, where it passed under the High-Level Aqueduct. The two aqueducts are both covered by sand dunes Fig. 4.9. Segment of the Low-Level Aqueduct exposed in Torgë’s excavation, looking as far as Negev’s excavation in Aqueduct north (after Torgë 2006: Fig. 3). Beach, which revealed the Low-Level Aqueduct to its full height (see Fig. 4.4). It is roofed by a barrel vault made of fieldstones, rubble and lime-based mortar, and coated inside and out with lime plaster (Porath 2002a: Type II, 2–3). The joint between the floor (5.46 m asl) and the sides is beveled, as in the built sectors further north (see above). A layer of travertine covers the inner sides of the channel up to 0.8 m above its floor, indicating an upper water level at c. 6.25 m asl. Segment D The exact point at which the Low-Level Aqueduct crossed through the northern city wall of Byzantine Caesarea is as yet unexcavated. The aqueduct was severely damaged here, and the vaulted roof did not survive. The southernmost point at which the Low-Level Aqueduct was examined is about 150 m south of the city wall of Byzantine Caesarea. The channel is plastered inside and outside and the joint between the floor (c. 5.25 m asl) and the sides (preserved up to 1.43 m above the floor) are beveled, as described above (Yosef Porath, pers. obs.). The termination of the Low-Level Aqueduct has not yet been revealed. It was not discerned in the excavations of the northern city wall of Herodian Caesarea by the Italian Mission in the 1950s (Dell’Amore et al. 1965). A westward extension of the right-side wall of the Low-Level Aqueduct, toward the High-Level Aqueduct, was revealed in test

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

trenches carried by the IAA (under the direction of Yosef Porath). This has been interpreted by Porath as evidence that the Low-Level Aqueduct ended in a large reservoir that flanked the eastern face of the final arches of the High-Level Aqueduct near the divisorium (Porath 2002b:121; 2006). Modifications to the Outlets of the Low-Level Aqueduct (Phase IVa) (Plans 4.6–4.8) As noted above, no significant repairs or additions were made along the entire length of the known segments of the Low-Level Aqueduct. Modifications made at the outlet from the reservoir and in Segment A (L2352, L2142, L2161; see Plan 4.1) were carried out in three sub-phases (IVa3–1; Table 4.1).

380

W2

Sub-Phase IVa3: Addition of Channel 1 (Plan 4.6) The first modification was made in the outlet from the distribution basin (L46), which was replaced with a larger outlet in the center of the distribution basin’s southern side (L2520; 0.4–0.7 × 2.1 m; flow threshold 3.38 m asl). The flow threshold of L2520 is 0.8 m lower than the original opening, which was blocked by W45 and sealed with a layer of light gray lime plaster (Porath 2002a: Type II, 2–3; see Chapter 3: Distribution Basin Sub-Phase IVa3). The new outlet opened into Channel 1 (C1; 2.5 m wide near L2520; floor elevation 3.37 m asl), which cut through L2352 of Segment A (above) and conveyed water to the flour mills to the west of the dam (see P1 Chapter 5). In this sub-phase, Outlet 2520 channeled water to both the flour mills and the Low-Level Aqueduct––regulated with 4 37 P2 the aid of a movable gate (L2521), inserted in vertical grooves (15–20 × 30 cm) P3 across Channel 1. One groove remained 4 20 4 37 in the left side of Channel 1, to the west L2520 of where it cuts through L2352. The 5 17 other groove (0.20 × 0.31 m) was carved 45 W C1 5 01 in a large dressed block (1.30 × 2.50 m, C2a L46 4 67 0.95 m thick) positioned on the right side 3 39 C2b 4 37 of Channel 1. This large block was later L2352 5 87 moved and used to block the entrance to 4 18 4 86 L2521 L2352 (W2124; Fig. 4.10; see Sub-Phase IVa2). Although the floor of L2352 is 0.8 4 67 m higher than the floor of Channel 1, the 3 37 guiding elevation of the flow in the LowLevel Aqueduct was that in Segment C 0 4 exposed in Aqueduct Beach (5.46 m asl; m see above; Negev 1964), whose floor is Plan 4.6. Modification in the outlet to the LowLevel Aqueduct from the distribution basin. over 2 m higher than that of Channel 1.

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CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

L2352

W2124

L2521 C1

Fig. 4.10. Location where Channel 1 cuts across L2352 of the LowLevel Aqueduct (blocked by W2124), looking south.

Regulating such large quantities of water from a single opening into two channels with such a difference in elevation was problematic, and apparently led to the next modification in Sub-Phase IVa2. Sub-Phase IVa2: Addition of Passage 4 (Plan 4.7) In the second modification, the water channeled to the Low-Level Aqueduct was diverted away from that allocated to Channel 1, which powered the flour mills (see Chapter 5). The entrance to the hewn section of Segment A of the Low-Level Aqueduct (L2352), in the southern wall of Channel 1, was blocked by W2124, built of a large block and several kurkar stones bonded together with lime-based mortar (2.85 m wide, preserved up to 5.11 m asl; Fig. 4.10). The Low-Level Aqueduct was now fed via Passage 4 (P4), added to the sluice south of Passage 3. Passage 4 was constructed without deepening the kurkar bedrock, and is preserved to a height of only one course (max. elevation 6.08 m asl). The passage has vertical grooves (15– 20 × 20 cm) for two movable gates in the

P1

P2 L2362 6 08

L2365 L2369

5 48

5 45

L2520 5 17

P3

P4

5 96

5 52

3 37

C1 L46 6 08

4 20

W2124 L2521

5 11 4 18

L53 L2352

0

4

Plan 4.7. Addition of Passage 4 (Sub-Phase IVa2).

m

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

eastern part of the passage, where the flow threshold is 5.52 m asl. A horizontal groove (7 × 25–30 cm) was hewn in the threshold stone of the eastern end to accommodate the easternmost gate and improve the seal (Fig. 4.11).2 The water was directed from Passage 4 to the aqueduct (L2352) via a channel (L53), the only remnant of which is a short, 0.65 m wide hewn segment. Although the sides of L53 have not survived, based on the water elevation in the reservoir and in the channel, its sides would have been stone built above the natural kurkar (here preserved to a max. elevation of 6.11 m asl). Apparently, the right side of L53 adjoined the upper part of W2124, which rose to approximately 7 m asl. In the remaining course of the Low-Level Aqueduct, downstream from W2124, no modifications were discerned in this sub-phase.

P3

P4

Fig. 4.11. Passage 4; note the groove for the gate at the eastern end, looking north.

A number of researchers have suggested that Passage 4 was used as a spillway outlet for the reservoir (Sa‘id 2002:35*; the late Yehuda Peleg, pers. comm.), but this suggestion is impractical as the sides of the Low-Level Aqueduct reached at least 6.5 m asl and the water entering P4 was channeled to the aqueduct. 2

CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

119

Sub-Phase IVa1: Addition of Passage 5 (Plan 4.8) In the final modification, the outlet to the Low-Level Aqueduct was via Passage 5, built at a location some 40 m south of the sluice and Channel 1, where earlier quarrying for the Lower Aqueduct (L403) had created a 4.5–5.0 m wide gap in the kurkar ridge. As the gap was too wide to accommodate a single movable gate, a pier was built (W5519; 2.2 × 4.0 m) to create two sub-passages (L5025 in the north: 1.3 m wide; L5026 in the south: 1.1 m wide; Figs. 4.12, 4.13). Vertical grooves for movable gates were cut in the sides of the sub-passages (5 × 12 cm in the sides of W5519, 20–30 × 25–40 cm in the bedrock sides). The vertical grooves reach a depth of 5.14 m asl in the south and 5.38 m asl in the north, from which it can be concluded that the flow thresholds in the sub-passages were at similar

L403 7 17 5 38

4 98

1

4 50 4 21

L5020

L5025 3 47

L5026

19

55

L403

W

5 45

4 44

L5521 1

5 50

5 83 5 14

L5020 Q2

0

4

m

7 00

6 00

L5026 L5025

W5519

5 00

4 00

L403 1-1

Plan 4.8. The vicinity of Passage 5.

3 00

120

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

L403

W5591

L5521

Fig. 4.12. Passage 5 and the Low-Level Aqueduct (L5521), looking west.

elevations. However, a dressed-stone pavement laid in the sub-passages created a flow threshold of 5.45 m asl, perhaps suggesting another phase here. From the double passage of Passage 5, a new course (L5521) was hewn for the Low-Level Aqueduct (19 m long) by enlarging L403 c. 1 m southward, to c. 2.1 m wide (floor elevation 5.00 m asl), up to the point where it previously exited Quarry 1 (L2161) and joined L403. Thus, the original northern part of the Low-Level Aqueduct was now obsolete (L2352, L2142, L2161). The southern end of Channel 2161 was blocked by a wall (W5518; 1.7 × 1.8 m), which forms the side of the Low-Level Aqueduct in this location (see Plan 4.1). Wall 5518 was built of two faces of dressed stones bonded with gray lime-based mortar and fieldstones. Its southern face was meticulously built and is preserved to a height of ten courses (up to 6.65 m asl). The upper part of its northern face (six courses high) was similarly built, but the lower part was less carefully finished—apparently because it was covered by an earth fill.

CHAPTER 4: THE LOW-LEVEL AQUEDUCT TO CAESAREA (STRATUM IV)

121

L5026

W5519

Fig. 4.13. Passage 5 with vertical groove in southern side, looking south.

The mortar between the upper courses of W5518 is smooth and contains ribbed potsherds. No further modifications were discerned in the southward continuation of the Low-Level aqueduct. After the Low-Level Aqueduct fell into disuse, its course to the south of Passage 5 (L5521, L5509; see Plan 4.2) became a quarry (Q2; L5020; see Chapter 6). Summary The Low-Level Aqueduct was designed to convey water from the Naḥal Tanninim reservoir to Caesarea for uses that have not yet been fully clarified––probably domestic use, irrigation, water-powered machinery, flushing the harbor, etc. During its operation, a number of modifications were made, all related to how the water was diverted from the reservoir. No significant or extensive changes were made along the aqueduct’s channel, apart from routine local repairs and maintenance. The water initially reached the LowLevel Aqueduct via an outlet (L46) in the distribution basin and later through a larger opening (L2520) that channeled water to the flour mills as well. Finally, the Low-Level Aqueduct was completely separated from the sluice—first by Passage 4 and subsequently by Passage 5. These modifications were apparently made to accommodate the changed emphasis in the reservoir’s operation—from providing water to Caesarea, to operating the flour mills. The progressive modifications attest to a process of ‘trial and error’ in response to changing needs on the one hand, and supply capability on the other. Nevertheless, no

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

findings from the excavations near the dam or along its course to Caesarea can explain the fact that the floor of the Low-Level Aqueduct near the dam is over 1 m lower than the floor near Caesarea (4.20 m asl in L2352 versus 5.46 m asl in Aqueduct Beach). This discrepancy was apparently solved by elevating the aqueduct’s side walls to a sufficient height. Sediments on the channel’s walls indicate that water flowed at an elevation of up to 6.3 m asl.

Y. Porath, U. ‘Ad and ‘A. a-S. Sa‘id, 2023, Naḥal Tanninim (IAA Reports 71)

Chapter 5

The Flour Mills (Strata IV–III)

Introduction The Naḥal Tanninim water facility was initially designed to supply water to Caesarea via the Low-Level Aqueduct (see Chapter 4). However, from its earliest stages, some of the water was evidently diverted to power flour mills. The feeder channels and operating levels of these mills were hewn into the kurkar ridge west of the sluice to the south of the dam. Water was initially channeled to power one mill via Channel 11, which flowed out from the sluice’s distribution basin (Phase IVa; see below). Later on in Phase IVa, the amount of water channeled for milling increased and the number of mills that may have operated simultaneously grew to six (M1–M6; Plan 5.1).1 Another mill was built on the Northern Dam that had three phases, the earliest dating to the Byzantine and probably contemporary to these (see Chapter 3; Porath, Gendelman and Arnon 2007:86*). The Muslim conquest of Palestine (completed in 640/1 CE) resulted in the economic and social disintegration of the city of Caesarea and its subsequent abandonment by most of its population (Porath 1996a:120; 2002b:127–129). Consequently, the flow of water in the Low-Level Aqueduct to Caesarea and the operation of the mills ceased, as did maintenance work on the dams and the reservoir system. The flow of water to Caesarea apparently was the first function to be stopped, due to the lack of consumers and because the flow threshold of the Low-Level Aqueduct was 2 m higher than that of Channel 1, through which the mills were operated. After a hiatus of several centuries, the flour-mill industry was revived and mills were built against the air face of the dam or adjacent to it (Stratum III; see Chapter 1: Plan 1.1). They were now operated by water channeled directly through tunnels hewn in the dam (W204), and also via Passage 3 of the original sluice, and thus the reservoir water was used solely for milling. It is reasonable to assume that after the Muslim conquest, the neglect of the dams led to a reduction in the surface level of the water in the reservoir; however, an elevation of 3.80–5.50 m asl would have sufficed to operate the new mills.2

At the northern end of Channel 8, there may have been another mill that was obliterated during construction of Mills 13 and 19 (see below). 2 The travertine deposits on the sides of the Low-Level Aqueduct, as measured at the Aqueduct Beach (see Chapter 4), attest to a water level of 6.30 m asl, from which it can be deduced that when the aqueduct was in use, the water in the reservoir reached at least this elevation. 1

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

P3

5 33

4 95

4 89 4 00

5 67

M13 M19

4 12

C8

1 71

1 72

1 12

2 98 3 78 3 01

3 33 3 17 3 75

C16

3 62

2 66

3 00

3 14

0 64 0 74

C18

3 78 3 29

4 10 3 62

2 81

1 60 4 95 1 81

0 98

4 89

2 76 1 73

2 05 3 27

2 38

1 5 51

3 70

3 53 6 01

6 14

C11

3 97 3 31

4 86

4 58

3 14

3 30

M2

4 27

4 97

5 57 3 30 4 17

4 18

5 68

3 34

5 92

C12

4 48

C17

3 28 3 22

3 37

C7

3 82

3 07

M3

1

L2521

5 81

3 71

2 91 1 92

C10

5 37 5 94

3 24

2 80

3 44 4 33

C2 C6

6 08

3 32

5 55 5 30

5 74

4 93 3 05

2 74

0 81

3 70

3 78 3 51 5 08

C15

2 35

M4

5 08 4 21

3 51

5 14 3 48

1 49

2 71

3 51

M1

4 68

3 37 C9 5 03

6 08

L2352

2 LLA

4 67 4 37

5 87

3 60

4 02 4 19

M6

3 77

4 80

4 03

4 03

3 39

3 92 5 39

C3

3 94 1 23

2

4 28

5 39 5 04

3

4 04

3 56 4 68

3

3 40

L2520 L46

5 17 3 37

W37

3 17

5 45

C13 3 24

4 43 3 28

3 22

M5

2 38 2 96

4 47

C14

3 21

4 74

M - Mill

3 66

C - Byzantine Channel 2 05

LLA - Low-Level Aqueduct 4 10

C - Ottoman Channel 0

Plan 5.1. General plan of Mills 1–6 and their feeder channels.

10 m

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CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

C11

1-1

6 00

5 00

6 00 C2

5 00

C1 C3

4 00

3 00

2-2

6 00 L2352 5 00

4 00

3-3

3 00

Plan 5.1. Sections.

It appears that some mills already operated in the Mamluk period (M14, M15 and probably M19, Phase IIIb; and the middle phase of the mill on the northern dam), and by the second half of the Ottoman period, the reservoir was an enormous millpond that may have fed up to 13 pairs of millstones simultaneously (M10–M16, Phase IIIa; six doubles and one single).3 Two main types of milling mechanisms were operated by the water from the reservoir (Fig. 5.1). During the Byzantine period (Stratum IV), a vertical paddle wheel (Fig. 5.1:a) operated the millstones in the hewn mills to the south of the dam. In Stratum III, a horizontal paddle wheel operated the millstones in the stone-built mills along the air face of the dam (W204), through which their feeder channels were hewn. Among the Stratum III mills, two subtypes were discerned: penstock mills (Fig. 5.1:b) and chute mills (Fig. 5.1:c).

Although Mills 10–16 are attributed to the Ottoman period, the archaeological and historical records provide no indication that all six mills operated simultaneously. 3

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

C

Milling floor A Runner stone

A B D

B Bedstone C Hopper

E

D Paddle wheel E Drive shaft for paddle wheel F Leverage beam G Penstock

Operating level

H Chute

(a)

C

A B

Milling floor

G

E

Operating level

(b)

D F

C

A B

Milling floor E

Operating level

(c)

H

D F

Fig. 5.1. The different propulsion methods used in the Naḥal Tanninim mills: a) vertical paddle wheel (shown here with discoid millstones, but also used with Pompeian-type millstones); b) penstock mill with horizontal paddle wheel; c) chute mill with horizontal paddle wheel (after Frankel 2003:48).

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

127

The Byzantine Hewn Mills (Stratum IV) The Naḥal Tanninim Dam and its adjacent mills were surveyed in 1974–1981 by a team from the Joint Expedition to Caesarea Maritima (Oleson 1985). Oleson was the first to suggest that a depression west of the dam’s sluice was the lower part of a flour mill with a vertical ‘undershot’ paddle wheel (see below) that powered two pairs of millstones (Oleson 1985:147). The IAA excavations at the Naḥal Tanninim Dam proved that Oleson’s suggestion was indeed correct, and that additional such mills existed here. The Feeder Channels to the Hewn Mills (Plan 5.1) To the west of the sluice, a group of flour mills was powered by water from the reservoir that reached the mills from the distribution basin via channels hewn in the bedrock (Fig. 5.2). The finds from the mill floors date from the fifth–seventh centuries CE, like those from the distribution basin (see Chapter 3), indicating that these mills operated in the Byzantine period, with a possible continuation of a few years into the Early Islamic period. The number of mills increased during the Byzantine period and the system of feeder channels underwent many modifications. In the final phases (B, A), six mills operated here with

C1

Fig. 5.2. Aerial photograph of the southern part of the dam showing the sluice (center), Channel 1 (C1) and the feeder channels branching off to the hewn mills.

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Table 5.1. Modifications in the Water Supply to the Hewn Mills (see Plan 5.1) Phase

Channel

Mill

Flow Threshold (m asl)

Changes

A

C1 and branches

M1–M6

3.38

Separated from water supply to Low-Level Aqueduct by W2124; sluice used only for mills

B

C1 and branches

M1–M6

3.38 (L2520)

C2 rendered obsolete

C

C2a

M6

3.96

C2b deepened

D

C2b

M6(?)

4.46

C11 rendered obsolete

E

C11

Unknown

> 5.52

a sophisticated feeder system that branched off from Channel 1. This system cut across earlier channels, attesting to the existence of several phases in the hewn flour-mill system. Five phases were discerned in the excavation (Phases E–A; Table 5.1). Phase E The earliest feeder channel is Channel 11 (0.6–0.7 m wide) that probably existed from the original phase of the sluice (IVb), coexisting with Outlet 46. The preserved segment of Channel 11 is 13.5 m long, beginning 18 m from the distribution basin and descending westward from 5.51 to 4.93 m asl. Its eastward continuation was destroyed by later quarrying below the level of its floor. It probably exited the distribution basin from the southwestern end and ran along a course similar to that of Channel 2 (below). The outlet of Channel 11 from the distribution basin would have been at a higher elevation than the flow threshold of the Low-Level Aqueduct (max. elevation 5.46 m asl, see above), in view of the slope of the preserved segment,4 a fact that may indicate a preference for diverting water from the distribution basin to the Low-Level Aqueduct. Nothing remains from the mill that was powered by the water in Channel 11, but it seems to have stood in the area where Mill 2 was later hewn. Channel 11 was cut in the west by the operational level of Mill 2 and in the east by Channel 10. Fragments of a bilingual inscription on a marble plaque apparently dating to the early fourth-century CE, were found in the vicinity (see Chapter 11). Phases D–C Channel 2 was probably hewn along the same route as the eastern part of Channel 11, to divert water from the distribution basin to Mill 6 (or an earlier mill in a similar location that was completely destroyed). Two phases are distinguished (D, C). Channel 2b was hewn first, and later deepened to become Channel 2a (Fig. 5.3). From Channel 2b, only a few segments of the floor and parts of the left side (c. 13 m long) are preserved, and the floor slopes down from 4.46 m asl in the east to 4.34 m asl in the west. In the second phase, Channel 2a was cut 0.5–0.8 m deeper than Channel 2b (3.97 m asl at the outlet of the distribution basin, and 3.44 m asl at the place where it is cut by Channel 7, 10 m

If the slope of the floor of Channel 11 in its eastern section was identical to that in the preserved section, then the floor of the opening was 6.30 m asl; if the slope was more moderate, it would have been lower than this. 4

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

129

C

D C1

Fig. 5.3. Channel 2, Phases D and C, looking west.

to the west of the outlet. The eastern part of Channel 2a curves northward from the course of Channel 2b for an unknown reason. At a distance of 1 m from the distribution-basin outlet, vertical grooves (5 × 5 cm) for a movable gate were hewn on both sides of the channel. The upper part of the left side of Channel 2a incorporated Channel 2b, which suggests that its upper part was closed off by some kind of construction into which the upper part of the gate groove was cut, but this was later disassembled. The deepening of the flow threshold in Channel 2a reflects an increase in the quantity of water that was diverted to the mills relative to the total quantity passing through the sluice.5 Channel 2 was cut by Channels 6, 7 and 8 of Phase B. Phase B This phase apparently corresponds with the first modification in the outlet to the LowLevel Aqueduct (see above). Channel 2 was blocked with a wide stone wall (W37; c. 3 m wide) that is preserved to the top of the distribution basin’s side. Channel 1 now flowed through the new outlet hewn in the distribution basin’s southern side (L2520; flow threshold 3.38 m asl), cutting across the Low-Level Aqueduct (L2352; see above). A sophisticated water system was installed to the west of Mill 6 to supply another five mills (M1–M5) via channels that branch off from Channel 1. The floor of Channel 1 slopes moderately, from 3.37 m asl in the east to 3.20 m asl in the west (overall length 54.5 m). Six feeder channels

No evidence was found to ascertain whether the deepening of Channel 2 in Phase C was due to an increase in the overall quantity of water flowing through the sluice, at the expense of the spillway water (which must have run into a special installation that has yet to be discovered), or whether it reflects a decrease in the water flowing through the Low-Level Aqueduct (in which case the quantity of water passing through the sluice remained unchanged). The first possibility seems the most reasonable, unless this is additional evidence for a process of trial and error. 5

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

branch off northward from Channel 1 (from east to west: C6, C7+C9, C10+C18, C12+C16, C13+C17, C14; 0.4–0.7 m wide). Channels 7+9, 10+18, 13+17 and 14 supplied Mills 6, 1, 3 and 5, respectively, while Channels 12+16 supplied Mills 2 and 4, making a total of six mills. The feeder channels that branch off from Channel 1 preserve a uniform level, with hardly any slope as far as the mills they operate. Channel 8 extends north from Channel 7 and reaches L49 (the western part of the diversion channel). In the course of the Byzantine period, stones were laid on the floor of Channel 8 to raise its floor level. After the Byzantine period, when the sluice was apparently no longer in operation, Mills 13 and 19 were built at the northern end of Channel 8, destroying whatever had stood at the end of Channel 8 (possibly another mill). The segment of Channel 1 between L2520 and the place where Channel 10 branches off, is 2.6 m wide. From there, it narrows gradually to 2.2 m, then to 1.45 m and 1.15 m after Channels 12 and 13 branch off (see Fig. 5.2). Apparently, reducing the width of Channel 1 from east to west was planned in advance and reflects the cumulative reduction in the quantity of water flowing through it after each branch. Channel 6 was apparently left unfinished and its floor (3.67 m asl) is 0.3 m higher than the floor of Channel 1; at its northern end, near the meeting point with Channel 2 (obsolete in this phase), is an unhewn step left at an elevation of 3.92 m asl. As the width of Channel 1 in the east was greater than that of the Low-Level Aqueduct, and its floor level was deeper, it was capable of conveying a larger quantity of water, attesting to the fact that in this phase, preference was given to providing water to the mills near the dam over channeling it to Caesarea via the Low-Level Aqueduct. A movable gate across Channel 1 (L2521) determined how much water was diverted to the mills compared to the Low-Level Aqueduct. Signs of erosion on the sides of Channel 1 show that water was at a uniform level for its entire length, no deeper than 0.5 m. Dressed blocks of kurkar resting on their narrow sides were revealed in situ (C10, C12) at the points where the channels branch off from Channel 1, apparently to control the amount of water diverted to the mills. In the sides of Channel 9, however, vertical grooves for a movable gate were discerned, which probably controlled the flow of water between Mill 6 and the hypothetical mill at the northern end of Channel 8.6 Phase A In this phase, the Low-Level Aqueduct was cut off from Channel 1 by the construction of W2124, and water was diverted to the aqueduct via Passage 4 (see Chapter 4). As Gate 2521 was rendered obsolete, the large block that had protruded from the right side of Channel 1 was removed and incorporated into the construction of W2124. The complete separation between the system feeding the Low-Level Aqueduct and that operating the flour mills enabled the water from the Naḥal Tanninim Reservoir to be used to its full potential.

The diversion of the water from Channel 1 into the feeder channels of the mills may have been controlled by raisable wooden gates in wooden frames fitted into the channels. A similar device was chosen to reconstruct the operation of the hewn mills during the modern-day conservation works. 6

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CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

The Mills Six hewn mills were partially or completely excavated west of the dam’s sluice (Plan 5.1:M1–M6; Table 5.2).7 The surviving operating levels all have a similar basic plan that can be reconstructed based on the preserved parts that were excavated. All these mills Table 5.2. Measurements of the Byzantine Hewn Mills (in m) Data

M1

M2

M3

M4

M5

M6

Average

Max. length of operating level*

4.7

5.2

4.8

5.0

Unclear

Unclear

4.9

Max. width of operating level**

4.8

5.6

5.6

6.1

6.4

Unclear

5.4

Width of feeder channel outside of mill

0.6–0.8

0.6–0.9

0.6–0.7

0.6

0.7

0.5–0.6

0.60–0.65

Difference in elevation of feeder channel between C1 and entrance to mill

0.21

0.1

-0.04

-0.02

0.04

0.04

Elevation of feeder channel at entrance (m asl)

3.01

3.24

3.1

(3.05) 2.92

Unexcavated

Elevation of bottom of wheel pit (m asl)

1.12

2.82 (3.05)

0.98

0.67

Unexcavated

Difference in elevation from feeder channel entrance to bottom of wheel pit

1.89

0.42 (0.19)

2.12

2.38 (1.68)

Unexcavated

Unclear

2.13

Width of feeder channel inside mill

Destroyed

0.6

0.5

0.5

0.5

Unclear

0.52

Width of longitudinal channel

Unclear

Unclear

1.0

1.1

1.0–1.2

Unclear

1.1

Unexcavated

1.8

Max. diameter of paddle-wheel grooves

1.44

1.82 (2.24)

Reconstructed elevation of paddlewheel axle (m asl)

4.05

2.15

Reconstructed elevation of top of paddle-wheel grooves (m asl)

4.77

3.06 (3.27)

Reconstructed elevation of bottom of paddle-wheel grooves (m asl)

3.33

1.24 (1.03)

Length of gear chamber***

?

?

2.0

1.9

2.3

Unclear

2.1

Width of gear chamber***

?

?

1.1

1.4

1.2–1.3

Unclear

1.2

* along the axis of the feeder channel ** along the axis of the longitudinal channel *** based on the best preserved of the two (although usually very little difference between them)

As only the upper part of Mill 5 was cleaned and it was not excavated to bedrock, its plan is unclear.

7

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

consisted of a deep rectangular space (4.9 × 5.4 m on average) hewn into the bedrock, whose longitudinal axis is on a general east–west direction, parallel to the river’s course (Plans 5.2, 5.3). The space is crossed by a longitudinal channel (1.1 m wide on average) on the same axis, and by a perpendicular feeder channel (0.52 m wide on average), both of which were hewn in the kurkar. The feeder channel entered the hewn rectangle from the south as a branch from Channel 1 and continued northward beyond the mill, toward the course of the river, and divided the rectangle into a left and a right wing (2.35 × 4.9 m on average). Each wing was in turn divided by the longitudinal channel, which widened into a rectangular depression (‘gear chamber’; 1.2 × 2.1 m on average) on the external side of each wing. On either side of the feeder channel, tall blocks of bedrock remained as pilasters connected to the sides of the hewn rectangles. Rectangular grooves were hewn in the sides of the rock pilasters and the channels (4–10 × 6–15 cm, 2–8 cm deep). Concentric, circular signs of wear are visible on the sides of the feeder channel. A flour mill powered by the force of flowing water that operated two pairs of millstones can be reconstructed from these remains (Fig. 5.4). The vertical paddle wheel was installed in the feeder channel and the operating shaft of the paddle wheel was placed in the longitudinal channel; in the rectangular depressions at either end were gears that transformed the horizontal motion of the paddle-wheel shaft into vertical motion to operate the millstones that were situated on an upper (milling) floor. The rectangular grooves in the bedrock sides were intended to fix and stabilize the mill’s drive system. The concentric signs of wear on the sides of the feeder channel indicate that the exterior diameter of the paddle wheel was about 1.8 m on average (Table 5.2). Thus, it is possible to calculate the location of the paddle-wheel shaft, but not the wheel’s precise diameter, as we do not know which part of it rubbed against the rock side of the channel. The feeder channels (apart from C12 of Mill 2, see below) entered the operating level of the mills at a height close to the center of the reconstructed paddle wheels, or Left wing

Right wing

Feeder channel Direction of flow 0

2 m

Fig. 5.4. Schematic section of a hewn mill with two pairs of millstones (drawing by Doron Add).

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

133

slightly below (Table 5.2), but no evidence is preserved to indicate where the water actually struck the paddle wheel. Three methods of operation are known from research on vertical paddle-wheel flour mills, based on the point where the water struck the wheel (Fig. 5.5; Curwen 1944:130–132, Fig. 2; Moritz 1958:132, Fig. 16; Avitsur 1963:89; Wikander 2000:373–376): Undershot (Fig. 5.5:A): The lower part of the paddle wheel is submerged in the feeder channel and is turned by the water flowing in the channel. The paddle takes up nearly the entire width of the channel, apart from a necessary gap to avoid friction. Overshot (Fig. 5.5:B): The water from the feeder channel flows out from a channel or a wooden penstock above the top of the wheel and is caught by the container-shaped paddles after they pass their highest point. The falling water, whose force is increased by the weight of the water in the paddles, turns the wheel. As in the undershot method, the paddle wheel is narrower than the channel to prevent friction. Breastshot (Fig. 5.5:C): The water from the feeder channel gushes out from a wooden trough or penstock and strikes the paddle wheel diagonally at a point about half its height. The paddles of the wheel are submerged in water, as in the undershot method, and the flow accelerates the wheel rotation. The breastshot method of operation combines the principles of the vertical undershot paddle-wheel method with those of the horizontal paddle wheel (see below). For the undershot method of operation, a constant flow must be provided at a fixed height along a section where the wheel’s paddles are submerged in the water. In this method, a ‘waterfall’ should be located beyond rather than before the paddle wheel to provide greater flow potential. A cascade of water breaking before the paddle wheel would interfere with the undershot operation, as it creates a vortex at the bottom of the chute causing the water to lose some of its impetus. In overshot-operated mills, the channel should terminate above the top of the wheel. In breastshot-operated mills, the feeder channel should terminate slightly lower than the paddle-wheel shaft. The plan of Mill 2 (Plan 5.2) and the concentric circular grooves left by the paddle wheel on the side of the feeder channel (max. diam. 1.44 m; see above on the limitations of accurately calculating the diameter of the wheel) indicate that it was powered by the

A

B

C

Fig. 5.5. Water propulsion methods for a vertical wheel: (A) undershot; (B) overshot; (C) breastshot (after Moritz 1958: Fig. 16).

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

2 33

2 71 3 01

2 80

4 58

C11

4 93

3 05 4 10 3 62

L2312

5 51

3 71

L127

4 27

L151

4 97

3 30

4 71 4 18

3 24

3 97 3 31

5 57

4 48 3 30

C12 L109

5 68

0

2

m

Plan 5.2. Plan of Mill 2.

undershot method. Feeder Channel 12 of Mill 2 was hewn with a moderate slope of c. 2% along 5 m (from 3.34 m asl where C12 branches off from C1, to 3.24 m asl at the entrance to the mill). After this point, beneath the wheel, the channel deepened to 2.82 m asl to form a sort of shallow wheel pit, continuing onward at a moderate slope (2.80 m asl at the outlet from the mill). At a later stage, changes were made to Mill 2, probably in preparation for the construction or modification of Mill 4 at its foot. Of these changes, two courses of dressed stones remain in situ in the longitudinal channel between the pilasters, laid to raise the foundation of the wheel shaft (by 0.45 m), and the floor in the northern half of Channel 12 was raised by one course of dressed stones (0.25 m) to reach an elevation of 3.05 m asl (L2312). The floor in Channel 12 may have been raised in order to adjust the size of the paddle wheel in Mill 4 (for breastshot operation) or to improve its method of propulsion using the overshot method (see M4, below). The stones laid between the pilasters in order to raise the paddle-wheel shaft are covered with a continuous layer of travertine (3–5 cm thick), while the stones that were laid on the channel floor have very little travertine, and the joints between them were bonded with lime-based mortar. Therefore, these remains probably represent several stages

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of modification. It would have required a corresponding raising of the wheel shaft in Mill 4 if the wheel remained the same size, or a reduction in the wheel’s radius by 0.25 m if the height of the shaft remained unchanged. The traces of concentric grooves correspond to a paddle wheel 1.44 m in diameter. The height difference between the entrance of the feeder channel and the bottom of the paddle wheel in Mills 1, 3, 4, and probably also in Mill 6 (Table 5.2), indicates that they were operated by a different method from that of Mill 2. The plan of Mill 4 (Plan 5.3) and the signs of wear from its paddle wheel, enable us to reconstruct the location of the paddle wheel’s shaft and the minimum diameter of the wheel, and to evaluate its method of operation. For example, the floor of Mill 4’s feeder channel was at an elevation close to 3.00 m asl before entering the mill (after a course of stones was added to the floor of C12; see M2 above), but it was later lowered to 2.82 m asl. The western face of the northeastern pilaster in Mill 4 (i.e., the right side of the longitudinal channel) bears traces of concentric circular grooves with a maximum diameter of 1.82 m. As the reconstructed center of the circles is at an elevation of 2.15 m asl, then the top of the paddle wheel was at least 3.06 m asl, too high for water from a wooden penstock or chute projecting from the top of the channel from Mill 2 to flow over the top of the wheel. Therefore, Mill 4 could not have

3 75

L2328 L2329 3

2 66 0 74

1

3 14

L196 2 74

2

0 64

1 06

C16

L162

L2314 2 81

2 1

1 92

C15

2 35 2 73

3 25 2 91

3 3 04 3 14

1 81

2 33

2 81

4 95

2 71 3 01 2 80

0

2

m

Plan 5.3. Plan and sections of Mill 4.

C12

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

4 00

3 00

2 00

L196

L2314 1 00 C16 0 00

1-1

4 00

3 00

L2314

L196

2 00

1 00 C16 0 00

2-2

4 00

3 00

2 00 L2314 1 00 C16 3-3

0 00

Plan 5.3. Sections of Mill 4.

been powered by the overshot or breastshot method. The data on the elevation difference between the feeder channel entrance and the bottom of the wheel pit in Mills 1, 3 and 5 (Table 5.2) indicate they were also operated, like Mill 4, with the undershot method.

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137

The Millstones The area of the mills and the distribution basin to the southwest of the dam yielded 28 fragments of basalt millstones discarded due to breakage or wear8 (Fig. 5.6; on the provenance of the basalt, see Appendix 5.1). Almost all of them (23) are of the ‘Pompeian’ or ‘donkey’ mill (‘Ad, Sa‘id and Frankel 2005).9 To the best of our knowledge, no archaeological excavation of a water-powered flour mill has produced millstones of the Pompeian type. In excavations of water mills that have been published to date, only discoid millstones have been found (e.g., in Athens, see Parson 1936; Rome, see Wikander 1979; Schiøler and Wikander 1983; Wilson 2003). In Pompeian millstones, the hourglass-shaped runner (catillus; two hollow cones connected at their narrow ends) was placed over a solid conical bedstone (meta), which was set in the floor of the installation (see Fig. 5.1a). The grain was poured into the funnel of the upper cone and the milling was achieved by rotating the runner. An ordinary Pompeian mill was driven by a person or a beast (donkey) pacing around the mill, attached to the runner by a wooden beam. In order to harness the runner, a wood and metal mechanism was fixed to two square protrusions carved into the narrow waist of the runner (for details, see Moritz 1958:74–90, Fig. 9, Pls. 4, 5, 7a, 9b). The ends of the wooden beam were inserted into square sockets cut in the protrusions. In the Naḥal Tanninim water mills that were designed to be driven by a paddle wheel, it was necessary to pass a driveshaft through the conical bedstone (Fig. 5.7) to propel the runner.

Fig. 5.6. Fragments of Pompeian-type millstones in the distribution basin, looking west.

The constant grinding of the stones wears down the grinding faces, reducing the weight of the runner, decreasing their efficiency, and eventually causing breakage. 9 Schiøler also mentioned a fragment of a Pompeian mill found in the Danish–Israeli expedition in 1984 (see Chapter 1), but its precise location was not noted (Schiøler 1989:142). 8

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

0

10

Fig. 5.7. Pierced Pompeian-type bedstone from Mill 4.

Among the fragments of Pompeian millstones found in the excavation were six large parts of conical bedstones (the average lower diameter is 45 cm). On the surface of three of these, diagonal grooves were hewn from top to bottom to improve their milling capability after they had been worn down from prolonged use (for similar grooves on discoid-shaped millstones, see Curwen 1944: Fig. 42; Moritz 1958:124, Fig. 13). In two of the bedstone fragments, the grooves are wide and deep (4–5 × 2–3 cm; Fig. 5.8a) on the lower part to enable the flour to slide easily down the mill, while on the upper, active milling part where the runner was placed on them, the grooves are shallow (up to 0.5 cm deep). On the third fragment, signs of grooving remain only on the upper part and are well worn (Fig. 5.8b).

a b

Fig. 5.8. Pierced Pompeian-type bedstones with hewn grooves from distribution basin.

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

139

Square protrusions were fashioned on the waists of eight fragments of Pompeiantype runners, four of which have square socket holes to secure the propulsion mechanism to the runner (Fig. 5.9). A horizontal wooden beam was evidently inserted between two depressions in the rim, crossing through the center of the runner to improve the rotation and stability of the runner above the bedstone.

0

10

Fig. 5.9. Runner with perforated knob from the distribution basin.

One runner fragment (Fig. 5.10), the best-preserved example from the excavation, had no socket holes hewn in the square protrusions, nor depressions in the rim. Instead, two rectangular holes were hewn 10 cm beneath the rim (4 × 4 × 5 cm), on an axis perpendicular to that of the protrusions. In this case, the runner may have been harnessed to the operating shaft by a metal clasp attached to the rectangular sockets. A similar method is seen in a relief on a Roman sarcophagus (Moritz 1958: Pls. 4a, 7a).

Fig. 5.10. Runner with unperforated knobs from the distribution basin.

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

At Pompeii in Italy, the diameter of the bedstones ranges from 45 cm (as in the present assemblage) to over 180 cm. The two hollow cones of the runner stones from Pompeii are symmetrical in their measurements (Moritz 1958:75–76, Fig. 8) and the waist is approximately halfway up the stone. No complete diameter of a runner stone was unearthed at the Naḥal Tanninim mills. However, the upper cones—the funnels for grain—are only half the height of the lower cones where the grinding took place. In the only runner stone preserved to its complete height (Fig. 5.10), the height of the upper cone is 24 cm, and the height of the lower cone is 46 cm. Similar dimensions are evident among the other runner fragments of which only the upper cones are preserved, with a maximum height of 20 cm. The reduction in the relative height of the upper cone in Pompeian-type millstones during the Roman–Byzantine periods is a known phenomenon (Curwen 1944; Moritz 1958). Some of the worn basalt Pompeian-type fragments were found in the accumulation (L2372) beneath the stone pavement (L2369) in the distribution basin (Sub-Phase IVa3; see Chapter 3: Table 3.5; Plan 3.17) together with finds dated to the sixth–seventh centuries CE (see Chapters 8, 9). In the bottom of the wall of Tunnel 47 in the east (W2507; see Chapter 3: Table 3.5; Plan 3.16; Fig. 3.39), a lead pipe from Sub-Phase IVa4 rested upon a fragment of a pierced Pompeian-type bedstone. This attests that a hewn mill or mills had already been operating for some time near the dam, and its millstones were worn and discarded long before the laying of Pavement 2369 in Sub-Phase IVa3. From this it can be concluded that the hewing of Channel 1, during the phase when the Low-Level Aqueduct was disconnected from the distribution basin, took place after a relatively long period during which the dam and the reservoir were used to power a flour mill, or mills, with Pompeian-type millstones. Most of the finds on the floors of the longitudinal and feeder channels of the hewn mills were potsherds from the sixth–seventh centuries CE (L158, L162, L2329, L2407; see e.g., Chapter 8: Fig. 8.1). These finds are later than those recovered from the accumulation above the rock floor in the distribution basin (fourth–seventh centuries CE; L2378; see Chapter 3: Plan 3.17: Section 1-1; Chapter 8: Figs. 8.2:10; 8.7:1), indicating that the intensive operation of the mills via Channel 1 dates slightly later than the initial operation of the distribution basin and the sluice.

The Mamluk and Ottoman Built Mills (Stratum III) During the Ottoman period (Phase IIIa), seven built flour mills were operated in the vicinity of the dam’s air face (M10–M16; Table 5.3; see Chapter 1: Plan 1.1). Mills 14 and 15, and apparently also Mill 19, were originally penstock mills in pre-Ottoman times (Phase IIIb), that were later converted into chute mills (see below). All the built mills were powered by a horizontal paddle wheel with a vertical shaft that propelled the millstones directly, without requiring a gear to transfer the rotation from one axis to the other, as in the earlier hewn mills. The feeder channels were hewn through the dam wall (W204) and channeled water directly from the reservoir to the paddle wheels. The water was delivered to the paddle wheel by way of a vertical penstock or a sloping chute (for a detailed description of the operating mechanisms, see Chapter 14; see also

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CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

Table 5.3. Details of Chute Mills 10–16 Mill

Feeder

Flow Threshold (m asl)

Notes

Plan

M10

Hewn tunnel through dam W204

4.03

Two built chutes

5.7

M11

Same

4.07

Two built chutes

5.7

M12

Same

3.88

One built chute

5.7

M13

C3 via P3

4.26

Two built chutes above M19

5.8

M14

Not preserved

4.01

Two chutes, the upper part hewn in the penstocks, the lower part built

5.4

M15

Not preserved

?

Two chutes, their upper parts hewn in the penstocks

M16

Hewn tunnel through Walls 215, 216 and 204

4.14

Two built chutes, their eastern parts in W215 and W216, their western parts in W204; the structure was restored following the excavation

5.6

Avitsur 1960:27–38).10 The feeder channel of M13, and of M19 that preceded it, was via Passage 3 of the original sluice (see Plan 5.1). As all the penstock mills were replaced with typical chute mills, it would appear that the chute mills were the latest in a series of mills connected to the dam. Of course, this conclusion is only correct for the relative dating of the mills built to the west of the Naḥal Tanninim Dam, and no generalizations can be concluded regarding the development of mills in Israel as a whole. Penstock Mills (Phase IIIb; Plans 5.4, 5.5) Mills 14 and 15 (Plan. 5.4) Mills 14 and 15 were similar in plan, although Mill 15 was less well preserved. In 1984, the upper part of Mill 14 was examined by the Danish–Israeli expedition (see Chapter 1; Artzy and Schiøler 1984–1986; Schiøler 1989), and in 2003, a section of the lower part was excavated in the framework of the present IAA excavations. Each mill comprised a rectangular structure attached to the dam’s air face (external dimensions c. 5.2 × 6.5 m), and was clearly built later than the dam (Plan 5.4; Fig. 5.11). On the eastern side of the structure, a pair of chimney-like cylindrical penstocks was incorporated, whose sides were built of dressed stones covered with lime plaster mixed with ground potsherds (Porath 2002a: Type II, 4-2).11 The penstocks were not preserved to their entire height (top of preservation 6.23 m asl). They decreased from a diameter of 1.4 m in the upper part to 1.2 m toward the bottom (at 5.00–4.50 m asl). The conversion from a penstock mill to a chute mill entailed the deepening of the original feeder channel and hewing into the upper part of the penstock to construct a chute. The dam to the east of

Mills with a horizontal paddle wheel are also known as ‘Norse mills’ or ‘Greek mills’ (see Forbes 1955:86–88; Wikander 2000:375–377). Penstock mills are also known as ‘drop-towers’, or aruba mills (Avitsur 1963:69– 71). 11 Avitsur, who researched the built flour mills attached to the Naḥal Tanninim Dam (see Chapter 1), suggested that Mill 14 was “a sort of proto-type for the penstocks in stream mills” (Avitsur 1963:71). 10

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

D5

W204

1 M14

5 42

2

4 01

2 5 70

1 0

6 00

4 m

6 00

Penstock

5 00

5 00

4 00

4 00

3 00

3 00

Chutes

2 00

2 00 1 00

2-2

1-1

1 00

Plan 5.4. Plan and sections of Penstock Mill 14.

Mill 14 was destroyed in a later period to 1.2 m beneath the preserved top of the penstocks. However, it is possible to reconstruct the feeder channel and to deduce the elevation of the water in the reservoir in the period during which the penstock mill operated. The nowruined feeder channel, which was shared by the two penstocks, cut through the dam from east to west and then split into two sub-channels, each leading to one penstock. The subchannels had vertical grooves (6 cm wide, 5 cm average depth) for raising gates that were 5.34 m asl at the bottom—approximately 0.8 m higher than the floor of the feeder channel

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

143

Fig. 5.11. Aerial photograph of Mill 14, looking west.

in the chute mill from Phase IIIa. These vertical grooves relate to a reservoir whose water level was higher than that which powered the chute mill during the Ottoman period. The feeder sub-channels, like the penstocks themselves, were coated with plaster preserved to an elevation of 5.77 m asl, indicating the level of the missing floors. As the vertical grooves for the gates damaged this plaster, the gates were therefore added after the initial penstock mill began to function. When the mills were later adapted as chute mills, the floors of the feeder sub-channels were deepened (see below) and the plaster was only preserved on the sides. Presuming that the water in the feeder sub-channels was about 25 cm deep, then the reservoir’s water surface was about 6.00 m asl at the time of the penstock Mills 14 and 15. The IAA excavation did not expose the entire lower part of the penstocks, as the water channels of the chute mills that replaced the penstock mills (M14, M15) were not disassembled. It can be assumed that there was an inner nozzle at the bottom of the penstock, as was customary in penstock mills known in the Levant (Avitsur 1960:33, Pl. A:6). Mills 14 and 15 can be tentatively reconstructed as characteristic penstock mills in which the water flowed through a nozzle and propelled the horizontal paddle wheel installed to their west. Each mill contained two milling units with discoid millstones that could operate simultaneously. It should be noted that the excavators of Mill 14 in 1984 suggested that there was a paddle wheel inside the penstock and that these mills operated as turbine mills, due to the narrower diameter of the penstock (Schiøler 1989:143; Fig. 3). However, in the

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

IAA excavation it became clear that the structure of Mill 14 lay to the west of the penstocks, thus refuting their suggestion.12 The excavation of Mill 14 revealed no diagnostic finds to indicate the date of its construction. It is clear that the mill was built after the dam was completed, as it was attached to the dam’s air face and not an integral part of it, but no data was found to establish the time lapse between the completion of the dam and the inauguration of the initial mill. The Danish–Israeli expedition dated the construction of the penstock mill to 340–385 CE, based on radiocarbon dating of a carbonized wood fragment taken from the mortar between its stones (Schiøler 1989:138). However, in our opinion, the date suggested by Schiøler for the construction of Mill 14 is earlier than the actual date for the following reasons: 1. Establishing the date of a building based on a carbonized wood fragment from mortar is problematic, as the sample may have been contaminated by limestone (whose carbon is of geological age), and changes can occur when water is added to oxidized limestone (‘extinguishing the lime’), or during the reconstitution of the lime mortar into calcium carbonate (CaCO3; see Porath 2002a:25). 2. It cannot be determined if the wood was burned soon after the tree was felled, nor how much time passed between its combustion and its addition to the mortar. 3. The level of the reservoir that powered Mill 14 was lower than that in the Byzantine period, when water flowed through the Low-Level Aqueduct, but higher than that in the Ottoman period (see below). 4. On the reservoir’s Northern Dam, the excavated flour mill had three phases. The feeder channel for the mill from the middle phase was consistent with a reservoir level of approximately 5.60 m asl, with a slightly lower level in the subsequent phase. The middle phase yielded finds that date its use to the thirteenth–fourteenth centuries CE (late Crusader–early Mamluk periods; see Porath, Gendelman and Arnon 2007). The level of the reservoir that powered Mill 14 (c. 6.00 m asl) was closest to that of the middle phase of the mill on the Northern Dam. 5. To date, no penstock mill can be attributed with any certainty to the Byzantine period (see discussion of Mill 19 below). The dating of the penstock mills discovered at Chemtou in Tunisia to the Roman period has been questioned by Wilson (1995), as the dating was not established by a scientific archaeological excavation. The mill at Chemtou was attached to the collapsed blocks of a bridge constructed during the time of the emperor Trajan (97–111 CE), and there is no way to determine the length of time between the collapse of the bridge and the construction of the mill. It can be assumed that the early phase of Mill 15—a penstock mill similar to the early phase of Mill 14, but less well preserved—operated in the same period.

The negation of this suggestion casts doubt upon the reconstruction of mills surveyed in Chemtou and Testour in Tunisia (Wilson 1995:499–502). 12

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CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

Mill 19 (Plan 5.5) Excavation beneath the chutes of Mill 13 (see below) revealed that the western part of the hewn diversion channel (L49), west of W2380, was blocked by a wide wall (W2526) that created a space (L2530). The western face of W2526 was a straight line between the rock sides of the channel, while the eastern face was designed with a pair of small arches (diam. 0.5 m) to function as nozzles to control the water flow (L2527 in the north, L2528 in the south; diameter 0.5 m). Any remains of the construction to the west of W2526 were destroyed when Mill 13 was built. It is possible that L2530 functioned as a large penstock for a mill (M19) with two pairs of millstones, both operated by a horizontal paddle wheel installed to the west of W2526. Mill 19 was fed via a channel (not preserved) that extended westward from the sluice above the fill of the distribution basin (originally Passage 3; see Chapter 3), but at a higher elevation (see Plan 5.8). At the bottom of the fill in L2530, a few sherds from the late Byzantine to the Crusader periods were found. If these finds are associated with Mill 19, then this is the earliest penstock mill in Israel to be dated by archaeological excavation. In addition, in the northern part of Mill 6, c. 2.5 m southeast of Mill 19, a patch of floor was uncovered (L2343; 2.40–2.50 m asl; see Plan 5.8) that appears to belong to Mill 19. The few pottery and glass fragments from fills beneath Floor 2343 (e.g., L2344, L2345) date to the post-Byzantine–pre-Ottoman period (Phase IIIb; see Chapters 8, 9).

4 70

L2527

1

0 70

1 60 4 47

W2

526

1 50

1 40

L2530

2 20

L2528

L2513

L49

1 60

2

2 60

W2380

2 2

1

0

m

C8 5 00

5 00 C3 45 00 00

W2380

45 00 00

C8

34 00 00

34 00 00

23 00 00

23 00 00 L2513 1-1

L2530

12 00 00

513 5.5. Plan and sections of Mill 19. Plan

2-2

12 00 00

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

Chute Mills (Phase IIIa; Table 5.3; Plans 5.4, 5.6, 5.7, 5.8) It seems that in the fourteenth century, or slightly later, the Naḥal Tanninim Dam was damaged by some unidentified event that caused the water in the reservoir to drop tens of centimeters to below the flow threshold of the feeder channels of the penstock mills (i.e., down to c. 4.50 m asl or less).13 The most probable reason for such a drastic drop is the collapse of a segment of the dam (or less likely, seepage through the masonry joints or under the foundations). This may be the collapse of the northern segment (Segment 7; see Chapter 3), between the modern breach made for Naḥal Tanninim in the 1920s and the kurkar ridge north of Mill 16 (see below). In the Ottoman period, the dam was renovated to renew the operation of flour mills, and the breach, or collapse, that had formed in the northern segment of the dam was repaired. It was sealed with a stone wall (W216; Plan 5.6; see Chapter 3: Fig. 3.12), which had two faces of small dressed stones and a core of light gray, lime-based mortar mixed with fieldstones and dressed/ashlar stones in secondary use. Six chute mills (see Chapter 3: Plan 3.1:M10–M12, M14–M16) were built along the dam’s air-face side and a seventh (M13) to the west of the sluice (Table 5.3). Two of these mills (M14, M15) were converted from penstock mills of Phase IIIb, and M13 was built over Mill 19, also of Phase IIIb. Six of the mills contained pairs of adjacent milling units, while Mill 12 was a single unit, making a total of 13 pairs of millstones. Water was channeled via the built chutes to horizontal paddle wheels that operated a pair of discoid millstones (Fig. 5.12). The water entered the chute through passages hewn in the dam, whose floor-threshold elevations are consistent with a water level of c. 4.00–4.50 m asl

Grain

Millstones

Milling floor

Water

Paddle wheel

Operating level

Fig. 5.12. Schematic reconstruction of the operating system of a vertical chute mill with discoid millstones from the Naḥal Tanninim Dam (after Moritz 1958: Fig. 15).

Such a drop in the water elevation could have resulted in the abandonment of the mills, or the construction of new mills adapted to the lower water level; it appears that the owners of the mills chose the second option. 13

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

147

in the reservoir. As noted above, conversion from a penstock mill to a chute mill entailed the deepening of the feeder channel and hewing into the upper part of the penstock, constructing a chute and extending the mill structure westward. The chute mills were abandoned when the Naḥal Tanninim Dam was breached in the first phase of the Kebara Swamp drainage project in 1922, and by the time of the IAA excavations, all of the mills were destroyed. Chute mills, including those on the Naḥal Tanninim Dam, are known from many places in Israel (Avitsur 1960:27–29; 1963:41–45, 69–71, 81–90, 114; 1976:80, Fig. 222:3). The Danish–Israeli excavations recovered most of the parts of the paddle wheel that was installed in Mill 11, which was conserved and reconstructed, and is currently on display in the Eretz Israel Museum, Tel Aviv. The IAA excavations yielded fragments of basalt discoid millstones and wood and metal parts of paddle wheels and the operating mechanisms (see Chapter 14). Mill 16, the best-preserved of the chute mills, was reconstructed following the present excavation, and is now a working mill. The chute mills are discussed from north to south.14 Mill 16 (Plan 5.6) This millhouse (7.5 × 7.5–8.0 m) contained two milling units, each operated by a horizontal paddle wheel powered by water from an independent chute. The paddle wheels were installed in the operating level, above which was the milling floor. The structure was roofed with two barrel vaults on an east–west alignment, preserved to a maximum height of 4 m. Above them was a flat roof. The southeastern corner of the mill adjoins the original air face of the dam. The building had an opening in its northern wall (1.25 × 2.90 m) and opposite it, in the southern wall, was another opening (1.05 × 2.15 m). An archival photograph of the western wall shows two windows, one on top of the other, the upper of which was smaller (Fig. 5.13). The western wall extended 0.3–0.5 m beyond the walls of the operating level to the north and south, creating pilasters in the western corners. Adjacent to the air face of the dam, south of the mill, remains of a north–south wall may have been a retaining wall for a walkway leading to Mill 15. Mill 15 This millhouse (c. 7.5 × 8.0 m) was built beside the dam as a double penstock mill (see above) and later converted into a chute mill. It was destroyed in 1922, when the feeder channels were used to breach the wall of the dam and drain the Kebara Swamps. From the extant remains, the outline of the milling floor above the operating level can be reconstructed.

Photographs in this chapter (and also Chapter 7) of the dam and the mills from the first half of the twentieth century, are located in the Kovlonov Archives of Kibbutz Ma‘agan Mikha’el and the Man and his Work Center in the Eretz Israel Museum (see also Avitsur 1960: Figs. 18–29). We would like to thank the late Judith Ayalon and the staff of the kibbutz archive, who provided the photographs and granted us permission to use them. 14

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YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

7 53

L6012

7 90

1

7 84 7 29

7 44

2 99

L6008 7 47

7 29

0 93

0 95

2 22

2 32

2 34

L6005

16 W2

3 02 2 41

W215

50

W2

L6003

6 09

L6001

L6002

2 1

4 03 5 94

M16

04

W2

2

m ini

ann lT

ha Na

M15

0

ach

bre

M15

5 m

Plan 5.6. Plan and sections of Mill 16. M16 1 M15

Fig. 5.13. Mill 16 with vaulted ceiling and flat roof, looking northeast.

3 83

149

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

W216

7 00

W216

6 00

5 00

L6001 4 00

W215 3 00

2 00

1-1

M16 W215

Modern cement roof

W216

Plan 5.6. Sections of Mill 16.

2-2

0

2

m

Mill 14 (see Plan 5.4) This mill was built as a double penstock mill and, like M15, was later converted into a chute mill. The eastern part of the later millhouse (c. 5 × 7 m), next to the air face of the dam, was excavated in the present excavations from the top of the chutes to their bottom. The chutes were hewn into the penstocks and their lower parts were built. The millhouse was built of roughly dressed stones of different sizes interspersed with small stones to align the courses. Archival photographs (Figs. 5.14–5.16) show that the millhouse extended an additional 7.5 m to the west (for a total length of c. 12.5 m), and had two large arches in the northern and southern walls, each with a span of approximately 5 m. The arches appear to be wall supports; however, as the photographs are unclear, the possibility that the arches supported a roof should not be ruled out. South of the modern course of Naḥal Tanninim, 10–18 m east of the dam, the lower section of a curved stone wall (W3513; 1.6 × 11.0 m, max. preserved elevation 4.58 m asl) could perhaps be interpreted as the eastern side of a feeder channel conveying water from the northern part of the Naḥal Tanninim Valley to Mill 14 (see Chapter 3: Plan 3.1). Its foundation, built of fieldstones and roughly dressed stones in random order, was laid on reservoir sediments (L3508; 3.32 m asl) containing Ottoman finds. The upper wall has two faces of dressed stones (each 0.25 × 0.30 m, 0.20 m high) with crumbly, light colored, limebased mortar and a core of small stones in a friable gray material. A layer of light colored soil abutting its western face may represent the elevation of the reservoir’s water. There is also a possibility that W3513 was first built as a diversion dam during the repair of the northern collapse, after which it was incorporated into a feeder channel.

150

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

M14

Fig. 5.14. The dam and Mill 14 (note the penstocks that were cut into when it was converted to a chute mill), looking northeast.

Building 1

M16 M14

M12

Fig. 5.15. The top of the dam functioning as a bridge, showing Mills 12, 14, 16 and Building 1, looking north.

151

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

Building 1

M16

M14 M12 M11

Fig. 5.16. Mills 11, 12, 14, 16 and Building 1, looking northeast.

Mill 12 (Plan 5.7) Mill 12 comprised one milling unit and a single chute. The millhouse was built 3 m to the west of the dam’s air face. Only the operating level (5 × 8 m) and the chute were preserved. The vault of the operating level angled slightly northward from the air-face side to improve the water flow in the chute. In the archival photographs (Figs. 5.15, 5.16, 5.18), the structure is complete, including the milling floor, with an opening to the south (c. 1.5 × 2.2 m) and a small window in the east. In the earlier photographs (Figs. 5.15, 5.16), the building has a roof sloping to the north made of branches arranged crosswise and overlain by twigs covered in earth and mud. A paved path led from the top of the dam to the opening, passing over a small bridge built of three vaults located west of Mill 11 (Fig. 5.16). The chute could be observed from the eastern window (Fig. 5.15). Between the building and the dam, south of the chute, three stairs were unearthed that may have provided access to the chute for cleaning and maintenance. Mill 11 (Plan 5.7) The two vaults of the operating level and the two chutes that conveyed water to the paddle wheels were preserved from the millhouse (5 × 10 m). The vaults of Mill 11, like that of Mill 12, were also built with a slight northward angle. The vaults continued west of the western wall of the mill and constituted part of the paved path that led from Mill 12 and Mill 10. The entrance to the milling floor was through an opening in the southern wall, to the south of which was a wide space shared with Mill 10. The archival photographs (e.g.,

152

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID

1

L4007

D3

2 27 1 79

4 39

1 38

2 31

M12

3 88 4 40 1 48 6 43

0 57 1 97

D2

2 36

04

2 08

W2

1

L4508

1 37

4 05 1 36

1 36

3 23

M11

5 24 2 27

2 03

0 49

1 47

1 51

2

L4510

0 58 0 62

1 47

2

4 11

2 39 2 67

2 13

0 55 1 45

L4505

1 95 3 01

4 41 4 12

0 91 1 43

2 74

2 07 1 47

M10

4 06

2 55

4 86 3 94

2 72 3 82

0 72 2 84

3

4 01

2 58

3

3 94 4 88 5 09 5 25

7 17 6 37

2 51

L4001 D1

7 17

0

5

m

Plan 5.7. Plan and sections of Mills 10, 11 and 12.

Fig. 5.16) show that Mill 11 had a westward-sloping roof made of wooden beams overlaid with Marseilles-type tiles, of which many fragments were discovered in the excavation. To the east of the millhouse, close to the vault supporting the chutes, a small oven (L4510) built of fire-resistant bricks was discovered. Mill 10 (Plan 5.7) This millhouse (5.5 × 8.0 m) is located approximately 5.5 m west of the dam’s original air face. The chutes and the vaults are perpendicular to the dam wall, in contrast to the vaults

153

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III) 8 00 7 00 6 00 5 00

W204

4 00 3 00

M12

2 00 1 00 0 00

1-1

8 00 7 00 6 00 5 00 4 00

W204 M11

3 00 2 00 1 00

L4508

0 00

2-2

8 00 7 00

M10

6 00 5 00 4 00

W204

3 00 2 00 1 00 0 00

3-3

Plan 5.7. Sections of Mills 10, 11 and 12.

of Mills 11 and 12. The foundations of the millhouse, preserved to 4.86 m asl, are based on bedrock. The northern wall of the milling floor had an arched opening (1.2 × 2.1 m) that was reached from the wide space shared with Mill 11. The archival photographs (Figs. 5.17, 5.18) indicate that the structure had a flat roof above the barrel-vaulted ceiling. It should be noted that Mills 11 and 12 are of a similar height (Fig. 5.16), while Mill 10 rises to a higher elevation (visible in Fig. 5.17). It is possible that Mill 10 had an additional floor above the milling floor.

154

YOSEF PORATH, UZI ‘AD AND ‘ABED A-S. SA‘ID Building 3 Building 5

M14

M15

Building 6

M10

M12

Fig. 5.17. The dam, looking southeast.

Building 5 Building 3 M10 M12

Building 6

M14

M16

Fig. 5.18. The dam, Mills 10, 12, 14, 16 and Buildings 3, 5 and 6 to the southwest of the dam, looking south.

155

CHAPTER 5: THE FLOUR MILLS (STRATA IV–III)

Mill 13 (Plan 5.8) This mill was built over the fills that blocked the distribution basin of Phase IV and the remains of Mill 19 from Phase IIIb (see above). The mill suffered from considerable destruction after the modern breaching of the dam, and by the time of excavation the only preserved elements were a section of Feeder Channel 3 with a vault above it (see Chapter 6: Fig. 6.7) and the chutes that were built in the western part of the distribution basin.15 04 W2

4 00 3 17

4 89

P1

5 33 4

P2

4

3 40

5 67

3

4 56

3 68

1

4 68

5 39

P3

2

Chutes

3 60

Vault

4 10

M6 1 61

5 39 3 77

4 19

C8 3 60

3 37

L2345

3 34

4 56

2

C3

5 45

5 60

4 89

4 02 3 51

4 28

3 97

2

L2343 L2344

1 71 1 4 03 M13 3 94

3 92

4 20

5 01 4 67

4 80

C2

5 03

5 08

0

4

m

00 57 00 00 46 00

M13

W2516 C3

C3

P3

53 00 00 00 24 00 31 00 00 2 00 1 00

1-1 6 00

C3

5 00

W2516 2-2

4 00

Plan 5.8. Plan and sections of Mill 13.

In one of the archival photographs (Fig. 5.18), part of a vault is visible to the west of Mill 10 and Building 6, and in the opinion of Uzi ‘Ad, this is the roof of Mill 13, similar to Mills 10 and 16. 15

Appendix 5.1: The Provenance of the Basalt Millstones Irina Segal

Among the fragments of basalt millstones recovered in the excavations at the Naḥal Tanninim Dam (see Chapter 5; ‘Ad, Sa‘id and Frankel 2005), six samples were submitted for provenance study (Table App. 5.1.1). These include four Pompeian-type millstones from the distribution basin southwest of the dam, dated by the archaeologists to the Byzantine period, and two discoid millstones from Mill 6 dated to the medieval or Ottoman period. Few studies on the provenance of ancient basalt millstones have been published to date. These include the geochemistry of basalt millstones from the eastern Mediterranean covering a wide time frame from the Neolithic to the Roman periods (Williams-Thorpe and Thorpe 1991, 1993), and a study of basaltic hopper-rubber millstones from Naḥal Tut and ‘En Ḥofez in Israel, dated on stratigraphic evidence to the second half of the fourth century BCE (Segal 2006). Comparison of the chemical composition of the basalt from the latter two sites with the database published by Williams-Thorpe and Thorpe (1993), revealed that three of them originated in Nisyros, a volcanic island located in the Aegean Sea, while the source of one sample was an area west of Tiberias in Israel. A chemical and provenance study of basalt artifacts dated to the Roman period from the Burnt House in the Old City of Jerusalem (Segal 2010) determined that six samples were comparable with the Tiberias source in Israel, while the seventh object, a vase, was from Nisyros in the Aegean Sea. The aim of the present study was to define the chemical composition of the basaltic objects from the Naḥal Tanninim Dam and to provenance them. Analytical Procedure The samples were ground in a corundum mortar. Chemical analyses of major elements and Zr were performed using fusion with lithium metaborate followed by measuring the concentration with an inductively coupled plasma atomic emission spectrometer (ICPTable App. 5.1.1. The Analyzed Samples Sample No.

Locus; Basket

Context

Type

Date

1

L2346; B23084/1

Mill 6

Discoid

Ottoman period?

2

L2346; B23084/3

Mill 6

Discoid

Ottoman period?

3

L2372; B23193

Distribution basin

Pompeian

Byzantine period

4

L2372; B23192

Distribution basin

Pompeian

Byzantine period

5

L2395; B23236

Distribution basin

Pompeian

Byzantine Period

6

L2395; B23235

Distribution basin

Pompeian

Byzantine Period

158

IRINA SEGAL

AES), Perkin Elmer Optima 3300. Minor and trace elements were determined using sintering with sodium peroxide. After dissolution, the elements Cr, Cu, Zn and Sr were determined using an ICP-AES spectrometer, and V, Co, Ni, Mo, Rb, Nb, Pb, Th and U by ICP-mass spectrometer (ICP-MS), Perkin Elmer Sciex Elan DRC II. Results and Discussion The results are presented in Table App. 5.1.2. The guidelines set out by WilliamsThorpe (1988) and Williams-Thorpe and Thorpe (1991, 1993) were used to establish the provenance of the studied objects. For the eastern Mediterranean, the source assignment can be presented by a flow diagram (Fig. App. 5.1.1). First, the provenance of each sample was defined according to its tectonic setting distinguished by Zr and TiO2 content: either Within-Plate (continental) origin or Island-Arc (volcanic) related. All the samples from the Naḥal Tanninim Dam contain relatively high TiO2 (≥2%) and the ratio of TiO2/Zr varies from 0.011–0.017; thus, all are of Within-Plate origin. In order to define the source of the Within-Plate samples, the TiO2 and Zr contents were compared with the Levantine and Egyptian volcanic rock fields illustrated in Williams-Thorpe and Thorpe (1993: Fig. 15). As the TiO2 content is more than 2% and the Zr content is 120–220 ppm, the analyzed samples are from the Levant. The Zr/Nb ratio for Within-Plate samples is typically 4–5, less frequently it reaches 8; Island-Arc samples have higher ratios, i.e., 12–25 (Williams-Thorpe and Thorpe 1993). As the ratio in the samples from Naḥal Tanninim varies from 3.5 to 4.3, it is consistent with volcanic rock from the Levant (Israel, Jordan and Syria), not from Egypt.

Table App. 5.1.2. Chemical Composition of Basalt Millstone Samples Wt. % Sample No.

SiO2

Al2O3

Fe2O3

TiO2

CaO

MgO

MnO

Na2O

K2O

P2O5

SO3

1

46.3

15.5

11.9

2.4

11.1

6.1

0.16

3.1

1.02

0.5