Page 1

E-BOOK VERSION

| FOREWORD | PREFACE | LIST OF CONTENTS |


Irrigation Tunneling

in Ancient Indonesia

A. Hafied A. Gany

IRRIGATION TUNNELING IN ANCIENT INDONESIA

Publisher The Indonesian National Committee of ICID, in Collaboration with Balai Irigasi, Balitbang P.U.


Irrigation Tunneling

in Ancient Indonesia

IRRIGATION TUNNELING IN ANCIENT INDONESIA By A. Hafied A. Gany Copyright Š 2012 by GANY

Publisher The Indonesian National Committee of International Commission on Irrigation and Drainage, in Collaboration with Balai Irigasi, Balitbang P.U. (Email: inacid_indonesia@yahoo.co.id; kairigasil@pu.go.id)

Cover Design: La Rane Hafied ISBN (PRINT VERSION) ISBN 978-602-7530-06-5

ii GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

INDONESIAN NATIONAL COMMITTEE OF INTERNATIONAL COMMISSION ON IRRIGATION AND DRAINAGE (INACID)

Foreword from the President of INACID From the long term irrigation development and management practices since the ancient time, we learned that Indonesia as the world largest tropical archipelago has quite a remarkable experience in traditional irrigated agricultural practices. Especially in the major islands, irrigated agriculture are under the fertile and prosperous land areas with distinctly uninterrupted natural condition, with constant river flows in the course of the remarkably virgin forest vegetations, and most notably under the well balanced natural ecosystem. Today, however, such a desirable natural condition has become scarce and yet the escalating degradation of natural condition in general and water ecosystem in particular, is continuously jeopardized by the hardly controllable human interventions against our Mother Nature. Despite that the development and management of water resources and irrigation in Indonesia has long been practiced with centuries of existence, the historical documents on water resources development in general, and irrigation practices in particular, has yet adequately fulfilling the curiosities for information on this distinct heritage of human life. This particularly true on tunneling technique that had long been practiced where the absence of transcriptions on such a paramount historical heritage would bring about devastating consequences against discontinuation of information on the way we nurture our life and environment through sustainable irrigation development and management, which in fact, has to be passed on to our GANY - INACID iii


Irrigation Tunneling

in Ancient Indonesia

future generations. This matter is quite important for the future generation to know the technique practiced by their ancestor and hence to be able to adopt the best practices and avoid repeating unsustainable practices their ancestors used to conduct. In an attempt to provide continuous linkages amongst the past and present practices on traditional irrigation techniques, particularly on the traditional tunneling techniques, such as planning, design, and construction, problems encountered during the development and operation and maintenance in chronological sequence. This has been done by compiling and accumulating the available historical evidences of traditional tunneling technique that had been practiced in the islands of Bali, Lombok, Java, and Sumatra with some examples of recent application by the villagers and rural traditional communities. This book illustrates briefly about the sequential history of irrigation from the early prehistoric ancient time, based on the stone reliefs displayed at the walls of ancient temples on Java, and traditional techniques practiced by the ancient Balinese agricultural community refers to as Subak and other inheritances of traditional irrigated agricultural techniques on Lombok, Java and other islands within the Indonesian archipelago. In my capacity as the President of the Indonesian National Committee of International Commission on Irrigation and Drainage (INACID) and concurrently as the Director General of Water Resources, Ministry of Public Works, I would like to express my congratulation for the publication of this book entitled “IRRIGATION TUNNELLING IN ANCIENT INDONESIA�. At the same time, I would also like to convey my sincerest appreciation and wholehearted gratitude to the author: Mr. A. Hafied A. Gany, Ph.D., P. Eng, as well as other supporting professionals from the Directorate General of Water Resources, Ministry of Public Works, Provincial and Local iv GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Government Irrigation Services of the Ministry of Home Affairs, Ministry of Agriculture, Research Institutes, NGOs, Professional Organizations, Universities and INACID members that I could not mention one by one, for their strenuous efforts and supports to make this publication possible. Jakarta, 1st April 2012 President of INACID,

Director General of Water Resources, Ministry of Public Works

GANY - INACID v


Irrigation Tunneling

in Ancient Indonesia

PREFACE Learning from experiences on traditional irrigated agriculture in Indonesia since the ancient time – among others: Subak in Bali, Keujreun Blang in Aceh Special Province, Tuo Banda in West Sumatra, Raja Bondar in Nothern Sumatra, Mitra Cai in West Java, Dharma Tirto in Central Java, Tudang Sipulung in South Sulawesi, Mantri Siring in South Sumatra, Ili-ili in Lampung – it has been concluded that the simpler the approach the easier the farmer to participate and adopt the appropriate technicalities and the more sustainable would be the irrigated agricultural practices. The ancient Subak irrigated agricultural practices in Bali, for instance, has been in existence and practiced from generation to generation for hundreds of years, and amazingly it is still continuously practiced today in modern Indonesia. In fact, there are various principles of sustainable traditional techniques that are still relevant to be adapted by any similar rural farming circumstances in this modern world. These include rotational water distribution during the water scarcity season, traditional technique on water measurement devices, traditional environmentally friendly agricultural practices and traditional tunneling technology which will be discussed in somewhat elaborated terms in this book. Beginning with an extensive experience to interact with the Balinese transmigrant farmers in Southern Sumatra with a number of technical visits to observe the Subak practices in Bali Island, as well as other traditional practices that are still practiced in Indonesia today, the author has been inspired to prepare a brief note, facts and figures about tunneling technology adapted by Subak and other traditional farming communities in Indonesia that has been amazed me after witnessing the unique figures in many technical observations. The initial preparation of this book vi GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

was began after being encouraged by series of discussion on the history working group (WG-HIST) of International Commission on Irrigation and Drainage – ICID on 21st ICID Congress, Tehran, Iran, 14 – 23 October, 2011. The author as the member of the History Working Group of ICID was encouraged to write about the practical aspects ancient irrigated agricultural technology along the passage of time in Indonesia. In the preparation of this book entitled “ I R R I G AT I O N T U N N E L I N G I N A N C I E N T INDONESIA” into the present format, the author is fully aware that the traditional practices on tunneling technique referred to are not necessarily replicable to other irrigated farming circumstances without adjustment with the underlying conditions locally. At least, however, it will give a comparative example about these undoubtedly successful and sustainable practices. The outline contents of this booklet include the introduction of tunneling practices in traditional farming communities, basic principle and rationale behind the tunneling approach, traditional planning and design as well as their related appurtenances, construction techniques on implementation practices. These include constraints and problem, operation and maintenance, as well as sustainable water distribution and management, and other detailed examples on technical as well as non technical aspects associated with the tunneling implementation with some example of the most recent applications of traditional tunneling technique by the local farmers in Indonesia. The author is highly indebted to a number of individuals as well as institutions in preparing the manuscript, but at least to mention the Government of Bali, West Nusa Tenggara, and West Java Provinces particularly to the Provincial Irrigation Services and to a number of local water users association (WUA) – that the author cannot mention one by one – for the generous preparation GANY - INACID vii


Irrigation Tunneling

in Ancient Indonesia

of data, information and direct interview with local WUA members during several field visits to the concerned provinces. A special gratitude addresses to Dr. Ir. Suyono Sosrodarsono (the former Director General of Water Resources, and later as Minister of Public Works of the Republic of Indonesia) for his endless encouragement, inspiration and guidance to the author for writing every aspect of water resources development and management that could be documented for enriching the literature on irrigation in particular, and in water resources in general. My special thanks are also addressed to Dr. Ir. Moh Hasan, Dipl. HE., Director General of Water Resources Development, Ministry of Public Works, and President of Indonesian National Committee of ICID (INACID) for his continuous support and encouragement for preparing the publication of this book. I would be highly indebted if I did not mention at least my senior colleague, Mr. Jelantik Sushila, BIE, the retired Head of Bali Provincial Water Resources Development Division, and his former staff Mr. Ir. I Gusti Made Suadnya, BE, for his comprehensive explanation on tunneling circumstances as well as provided the related data and information, when I visited them in Bali prior to the writing of the manuscript. Thanks are also addressed to all colleagues and resource persons in West Nusa Tenggara, and West Java Provinces that I could not mention one by one, for every help, assistance, and encouragement during the preparation of the manuscript of this book. The last but not least, the author also appreciate the assistance of Mr. Drs Budianto, Executive Secretary of the Indonesian National Committee of International Commission on Irrigation and Drainage, and Mr. Ir. Iskandar Andi Yusuf, M.Sc., Senior Researcher of the Research Institute for Water Resources, Ministry of Public viii GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Works, aswell as Mr. Endang Wachyan, M.Sc., and Mr. Dwi Kristianto, Chief of Research Station on Irrigation, Ministry of Public Works for their intensive and continuous assistances to support preparing this book. Without which, this work has never been completely materialized.

A. Hafied A Gany Jakarta, Indonesia, March 09, 2012

Special

thank is   addressed   to   my   senior   colleague,   Mr.   Jelantik   Sushila,   BIE,   The   retired   Head   of   Bali   P r o v i n c i a l   W a t e r   R e s o u r c e s   Development   Division.   At   his   80th   he   strenuously   accompanied   me   to   the   Subak   Museum   in   Tabanan   District   8   November,   2011   for   showing   and   explaining   the   history   of   tunneling   technique  in  ancient  Bali.  

GANY - INACID ix


Irrigation Tunneling

in Ancient Indonesia

LIST OF CONTENT Foreword from the President of INACID ...................

iii

PREFACE ......................................................................

vi

List of Content ...............................................................

x

List of Figures ……………………………………………..

xiii

List of Tables ……………………………………………….... xx CHAPTER I: INTRODUCTION ..................................

1

General illustration of the zone location of tunnels: .......

7

CHAPTER II: TUNNELING PRACTICE IN BALI ISLAND ...................................................................

9

2.1. Basic Philosophy of Organizational Arrangement ...

13

2.2. Equipments, Tools and Facilities..............................

18

2.3. Planning, Designing Staking Out Preparation..........

27

A. Land Surveying for Determination of Tunnel Alignment ............................................................

28

B. Determination of Tunnel Size ..............................

30

2.4. Construction (Excavation) of Tunnel .......................

42

2.5. Controlling the Straightness of Tunnel Alignment ..

47

2.6. Length of Construction Period .................................

47

2.7. Problems on Construction of Tunnel........................

49

CHAPTER III: TUNNELING PRACTICE IN LOMBOK ISLAND ................................................................... 51 CHAPTER IV: RECENT TUNNELING EXPERIENCES IN MAJALENGKA AND TASIKMALAYA DISTRICTS, WEST JAVA PROVINCE.................. 70 4.1. Cikarag Village, Majalengka, West Java ..................

70

4.2. Kampung (village) Neglasari, Panca Tengah, Tasikmalaya District ................................................

73

x GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

4.3. SOCIAL-ECONOMIC PROBLEMS AND THE STRIFE FOR PROVIDING ADEQUATE RICE AS STAPLE FOOD....................................................................... 75 4.4. A BREAKTHROUGH OF A VILLAGE-WOMAN (IBU YUYU YUSANAH) IN PARTICIPATORY IRRIGATION........................................................... 76 A. The Strive for Development ................................

80

B. Development of Irrigation Infrastructures ...........

82

C. Preparatory Works and Community Organizing..

89

D. Problem encountered and solutions .....................

89

4.5. SUCCESSFUL APPLICATION OF ANXIENT TRADITIONAL TUNNELING TECHNIQUE BY AN ENTHUSIASTIC WOMAN ................................... 91 A. Indigenous Technology........................................

91

4.6. SUCCESSFUL APPLICATION OF ANXIENT TUNNELING TECHNIQUE BY A VILLAGER (ABDUL ROJAK) IN TASIKMALAYA DISTRICT ...............................................................

98

A. Irrigation Development, Simple Planning, construction and implementation ......................

98

B. Irrigation Weir and Fore-Canal ........................... 100 C. General Feature of the Fore-Canal ...................... 104 D. General Feature of the Tunnel ............................. 106 E. Determination of the Size and Bottom Slope ... 106 F. Construction Implementation ......................... 110 G. Operation of the Tunnel and Irrigation Scheme ........................................................... 111 H. Maintenance of the Irrigation Scheme ............. 112 I. Appreciation from the Government .................. 113

GANY - INACID xi


Irrigation Tunneling

in Ancient Indonesia

CHAPTER V: TUNNELING EXPERIENCE IN BATANG PANGIAN, TANAH DATAR DISTRICT, WEST SUMATRA PROVINCE.......................................... 117 5.1. BRIEF REVIEW OF IRRIGATION IN WEST SUMATRA PROVINCE.......................................... 117 5.2. TRADITIONAL IRRIGATION AND TUNNELING .......................................................... 120 CHAPTER VI: CAPACITY BUIDING, OPERATION AND MAINTENANCE .................................................... 129 6.1. INDIGENOUS TECHNOLOGY ............................. 129 6.2. OPERATION AND MAINTENANCE .................... 134 CHAPTER VII: LESSON LEARNT ............................ 139 CHAPTER VIII: CONCLUSION................................. 145 BIBLIOGRAPHY ......................................................... 149

xii GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

LIST OF FIGURES Figure 1.1. General map of Bali Island ..................

3

Figure 1.2.-1.3. General map of Bali Island ...........

4

Figure 1.4. General map of Bali Island ..................

4

Figure 2.1. General map of Bali Island ..................

9

Figure 2.2. Typical layout of irrigation network and function of tunnel as fore channel irrigation networks in Bali ............................................... ....11 Figure 2.3. Basic Principle of working mechanism ....................................................... ....16 Figure 2.4. Measurement of length by human organs ............................................................... ....17 Figure 2.5. Calibration equipment (left); and the undhagi demonstrate the calibration process (right) .........................................................................20 Figure 2.6. The details of the pengajing duhur survey equipment ........................................................ ....22 Figure 2.7. The picture pengajing duhur survey equipment (made of bamboo), kept at the Subak Museum Tabanan Bali ..................................... ....23 Figure 2.8. The sketch of pengajing dasar survey equipment for measuring the slop or tunnel leveling.............................................................24 Figure 2.9. The undhagi (left) demonstrate the use of pengajing dasar survey equipment for measuring the slop of tunnel. Prototype of pengajing dasar kept at Subak museum, Tabanan (right) .......... ....24 Figure 2.10. The undhagi (left) demonstrate the use of survey equipment for measuring the straight GANY - INACID xiii


Irrigation Tunneling

in Ancient Indonesia

alignment of open channel. This survey equipment kept at Subak museum, Tabanan, Bali (right) .. ....25 Figure 2.11. The measurement of the difference of level between one spots to another by using “pengajing duhur�, which is almost similar to the present technique .......................................................... ....25 Figure 2.12. The undhagi (left) sets the pengajing duhur survey equipment before surveying the level difference. Prototype of survey equipment kept at Subak museum, Tabanan, Bali (right) ............. ....26 Figure 2.13. General sketch of the measurement of the height of the water and height of the water level, so they can decide the slope of the tunnel and the height of the weir they plan to make................ ....27 Figure 2.14. Schematic longitudinal diagram of the land survey for determination of the measurement of the tunnel layout across the hill (munduk) .. ....29 Figure 2.15. Schematic reference for tunnel alignment and cross-section for staking out of the actual field implementation ................................................ ....30 Figure 2.16. Typical tektek water measurement device ............................................................... ....32 Figure 2.17. Typical tektek water measurement device ............................................................... ....33 Figure 2.18. Typical figure of tektek water measurement device, based on measurement of land size to be irrigated .................................... ....33 Figure 2.19.a & b. Left, is the crawl type, and right is the squat type measurement ............................. ....34 Figure 2.19.c. The standing type measurement standard .........................................................................35 xiv GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 2.20. The tunnel lay out with the location of horizontal as well as vertical aeration hole at the tunnel of Tukad Pangiangan Irrigation Scheme ............................................................. ....37 Figure 2.21. Pictures to show the general example of typical aeration holes with different functions, A = for inspection, B = horizontal air circulation, C = side spill way for excess water; and D= vertical aeration hole for lighting and air circulation ........................................................38 Figure 2.22. Cross-section of the tunnel and the notch (groove) for placing the coconut oil fuel lamp lighting ............................................................. ....39 Figure 2.23. A picture showing documentation of tunnel features written at pieces of bamboo, which is currently kept at Subak Museum in Tabanan Bali .........................................................................42 Figure 2.24. Some traditional tools used for tunneling, kept at Subak museum, Tabanan, Bali. A = pickax for hard soil and rock excavation; B = ordinary pickax for ordinary soil; C = Slope level; and D = Ruler and 90 degree guide ............................... ....45 Figure 2.25. Some traditional tools used for tunneling, kept at Subak museum, Tabanan, Bali (left); and a fire squirt (blower), for maintaining the steel tools during operation (right).................................... ....45 Figure, 2.26. Pictures showing the workers who are working for excavating the tunnel ................... ....46 Figure 3.1. General map of Lombok Island ...........

54

Figure 3.2. General layout of Sindang Gila Irrigation Area.................................................................. ....55

GANY - INACID xv


Irrigation Tunneling

in Ancient Indonesia

Figure 3.3. General condition of irrigation area, currently served by Sindang Gila Tunnel ........ ....56 Figure 3.4. The present condition of Sindang Gila Weir, 200 m upstream of the tunnel, after improvement by the government ........................................... ....59 Figure 3.5. Left, present condition of Sindang Gila Aqueduct after reconstruction by the government; right, upstream entrance of the tunnel, after improvement by the government ..................... ....60 Figure 3.6. Left, present condition of the downstream outlet of Sindang Gila Aqueduct after reconstruction by the government; right, typical aeration hole at the distance of about 50 m from each other ......................................................... ....60 Figure 3.7. General condition of irrigation area, currently served by Tibu Pungkur Tunnel........ ....65 Figure 3.8. The present condition of Tibu Pungkur Weir, 200 m above the old weir, improved by the government ...................................................... ....66 Figure 3.9. Left, present condition of upstream inlet of Tibu Pungkur tunnel after improvement by the government; right, typical aeration hole located scattered along 1,750 m tunnel ........................ ....66 Figure 3.10. General Layout of Ledang Bur Tunnel at the Village of Kali Jaga Selatan, Aik Mel Sub District Lombok, for serving 215 ha of irrigation area ................................................................... ....67 Figure 3.11. The local leaders of Ledang Bur Irrigation Scheme are at the meeting for discussing the way to resolve the problems they are facing ........... ....68

xvi GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 3.12. The inlet of Ledang Bur Tunnel before routine maintenance after the flooding season (left); Routine Cleaning of tunnel (right)......... ....68 Figure 3.13. The fore-canal and the main weir Ledang Bur Irrigation Scheme after reconstruction by the government (left); Community leaders (right) ....69 Figure 4.1. Location map of Majalengka and Tasikmalaya Districts of West Java Province .. ....70 Figure 4.2. Typical terrace paddy field system in Cikarag Village ................................................ ....72 Figure 4.3. Typical terrain of Neglasari Village without irrigation .......................................................... ....74 Figure 4.4. Yuyu Yusanah in her house ..................

77

Figure 4.5. Rural community profile of Cikarag Village, Kabupaten Majalengka ...................... ....77 Figure 4.6. Yuyu Yusanah’s paddy field .................

82

Figure 4.7. Situation Map of Irrigation infrastructures in Cikarag Village, Majalengka District, West Java Province ........................................................... ....85 Figure 4.8. The Cross-Section of the tunnel developed by Ibu Yuyu Yusanah ....................................... ....86 Figure 4.9. Simple Rock-fill weir ..........................

87

Figure 4.10. Improved of Simple Rock-fill weir....

87

Figure 4.11. Downstream view of the original tunnel................................................................ ....88 Figure 4.12. Sketch of upstream view of the original tunnel................................................................ ....88

GANY - INACID xvii


Irrigation Tunneling

in Ancient Indonesia

Figure 4.13. Free intake was made of a massive rock .................................................................. ....94 Figure 4.14. A simple gutter made of a split trunk of palm sugar tree ................................................. ....94 Figure 4.15. A semi water tight gabion weir was given by the research institute for water resources, as a technical assistance .......................................... ....97 Figure 4.16. Rock fill structure on the upstream tunnel inlet was also given by the research institute of water resources as a technical assistance ......... ....97 Figure 4.17. The main weir before redesign by the Local Government (1); Rice cultivation along the left bank of the fore canal (2); Profile of the villagers in Neglasari (3); rice cultivation on Irrigation Scheme (4)....................................... ....99 Figure 4.18. The location of old weir at about 15 meters upstream of the new weir (submerged at about 30 cm below the water level), the condition is still stable ..................................................... ..101 Figure 4.19. The weir after redesign and reconstructed by the local government (1); Side spill way at the fore canal (2); the reconstructed canal bank (3); the canal parallel with the steep river bank (4)...... ..102 Figure 4.20. General lay out (non-scale map) of the Abdul Rojak Irrigation Scheme ....................... ..103 Figure 4.21. Typical paddy field at the lowland valley of the Abdul Rojak Irrigation Scheme ............. ..104 Figure 4.22. The average profile of fore canal at the rock .................................................................. ..105

xviii GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 4.23. The general condition of fore canal which was excavated along the steep rock bank of the hill along the river .................................................. ..103 Figure 4.24. The middle part of the tunnel (1); The entrance of the tunnel (2); The downstream of the tunnel (3); and Transition of downstream and upstream which was not match with the tunnel axis during construction (4) .................................... ..107 Figure 4.25. The photographs of the tunnel, illustrating the size of the excavation which is somewhat over sized ................................................................. ..108 Figure 4.26. Traditional measurement for determining of the slope of the tunnel base ......................... ..109 Figure 4.27. A Rojak receiving from President Soeharto, Presidential award Satya Lencana Pembangunan for remarkable achievement on infrastructural development ............................. ..114 Figure 5.1. General map of West Sumatra province ........................................................... ..117 Figure 5.2. General location map of Batang Pangian Irrigation Scheme, Tanah Datar District, West Sumatra Province ............................................. ..120 Figure 5.3. The Pangian Canal at the downstream of tunnel................................................................ ..121 Figure 5.4. The downstream outlet of the tunnel ... 122 Figure 5.5. The center aeration hole of the tunnel . 124 Figure 5.6. In 1983 the government decided to restore the scheme by changing the function of the 400 meters tunnel with close conduit channel at the diameter of 65 cm at the total length of 1.10 km .................................................................... ..125 GANY - INACID xix


Irrigation Tunneling

in Ancient Indonesia

Figure 5.7. The outlet of the 65 cm pipe and diversion box after the tunnel have been replace with 1.1km pipe .................................................................. ..126 Figure 5.8. The 65 cm diameter of pipe replacing the tunnel is now suffered from lack of maintenance ..................................................... ..127 Figure 7.1. The sketch for detail mechanism of the sun light reflector ................................................... ..141 Figure 7.2. Photograph of the sun light reflector, at the field .................................................................. ..141 Figure 7.3. The sketch of the sediment cleaning kit ......................................................................... ..142 Figure 7.4. Photograph of operational use of the cleaning kit ...................................................... ..142

xx GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

LIST OF TABLE Table 2.1. Tools for preparing surveying equipment ........................................................ ....19 Table 2.2. Calibration equipment ...........................

19

Table 2.3. List of flow characteristic base on traditional Balinese Experience......................................... ....41 Table 2.4. List of construction equipment and .......facilities Experience .........................................

43

Table 3.1. Irrigated paddy field area West Nusa Tenggara by irrigation type, 2002 .................... ....52 Table 5.1. Irrigated Rice Field Areas by Irrigation System, 2002.................................................... ..118 Table 6.1. List of irrigation tunnels per District in Bali .........................................................................135

GANY - INACID xxi


Irrigation Tunneling in Ancient Indonesia

CHAPTER I

INTRODUCTION Historically, Irrigation in Indonesia has been significantly related with lowland paddies as the staple diet of the people since the ancient time. However, no evidence had been indicating the exact time when irrigated paddy was initially practiced in Indonesia. Some scholars argue that the ancient migrants of Don-Sun Civilization from Asian continent during the decades of BC stranded in the Brantas Delta of the Eastern Java Island and ever-since decided to settle in the Kediri Area (as known today). This ancient civilization is evidently believed to be the origin of irrigated agricultural practices in Indonesian Archipelago (Angoedi A., 1984. pp.3-4.). According to the existing folklore, irrigation in Indonesia must have been practiced longer before the Hindu people came to the area. The first Hindu generation came to Indonesia, named the Java Island after the JawaDwipa Island, which derives from the compound words “jawawut” means paddy and”dwipa” means island, or Paddy Island (Java Island). As the matter of fact, there are a number of traditional irrigated agricultural practices that had been descended from ancient Indonesian civilizations such as -the “Subak” System in Bali Province, “Dawur Pranatamangsa” in Central and East Java Provinces, “Tuo Banda” or “Siak Bandar” in West Sumatra Province, “Tudang Sipulung” in South Sulawesi, “Panriahan Pamokkahanan” and “Siauga Parjolo” in North Sumatra, “Panitia Siring” in South Sumatra and Bengkulu Provinces, including some institutional based traditional agriculture such as “Ulu-ulu Desa”, and “Ulu-


Irrigation Tunneling

in Ancient Indonesia

ulu Vak” in Central Java, “Raksa Bumi” in West Java, “Ili-ili” in East Java, “Malar” or “Ponggawa” in Sumbawa Island, and “Kejrueng Blang” in Aceh Province – and yet still currently being implemented in many of today’s irrigated agricultural communities in the respective areas. For example from the ancient agricultural calendar referred to as the Pranatamangsa (Box 1).

GANY - INACID 2


Irrigation Tunneling

in Ancient Indonesia

Concerning irrigated agriculture in Indonesia, it is apparent that the ancient generations have already been practicing the ancient technique for a fairy long time. This matter can be seen from the artefact message at the stone panels and wall of some temples on Java as well on the outer islands, both by means of rain fed as well as by application of irrigation technique however simple it was. In Borobudur temple, for example, many stone reliefs indicating agricultural practices during the ancient time by using tool which similar to present practice.

01

Figure 1.1. A stone relief at Borobudur Temple illustrating agricultural cattle land-preparation at the ancient time

Another example of the ancient message of stone relief of the Trowulan museum, East Java illustrating the lowland paddy cultivation, and illustrating the bird eye view of lowland paddy plots, similar with present practice. Other stone relief from Borobudur Temple unearthed from the temple foundation (during restoration) referred to as Karmawibangga, also support the idea of irrigation practice since before the 7th Century AD.

3 GANY - INACID


Irrigation Tunneling

02

in Ancient Indonesia

03

Figure 1.2. (left). A stone relief from Trowulan Museum, East Java illustrating rice transplanting; and Figure 1.3. (right) illustrating the bird eye view of lowland paddy irrigated plot. Source: Balai Studi dan Konservasi Candi Borobudur, Wiwit Kasiati, 2000

04.4

5.

Figure 1.4. A stone relief from Borobudur temple at the base of Karmawibangga (Series O No. 65) illustrates the ancient farmers working together to conduct plant surveillance (pest and bird control) at ripening stage of paddy prior to manual harvesting.

GANY - INACID 4


Irrigation Tunneling

in Ancient Indonesia

The relief clearly illustrating the paddy cultivated by the farmer during the harvesting season by practicing pest control, such as birds, rats and assisted by domesticated dog. This figure also illustrates the way of the farming community to work together taking care of the ripening rice cultivation prior to manual harvesting, as are still practiced today. The oldest inscriptions on irrigation works in Indonesia indicate that the first irrigation infrastructure in Indonesia was constructed at the Tugu Village near the Cilincing River on the Fifth Century AD. The Tugu stone inscription placed at the Tugu Village near Cilincing River, Northern Jakarta. (Angoedi, 1984., p.28).

The Tugu Stone inscription is now kept at the National Museum Registered at No. D.124. (After Angoedi, 1984, p.28)

In East Java, the Harinjing stone inscriptions that are presently kept at the National Museum in Jakarta, explained that the Harinjing dyke was build for protecting irrigated agricultural area from occasional eruption of Mount Kelud volcano. 5 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

The Harinjing stone inscription near Jombang (Pare) at the village of Siman Krajan. The original inscription is now kept at the National Museum Registered under Reg. No. D.173

In spite of the ancient evidences concerning paddy so far there is no evidence indicated by ancient message on irrigation technology, except the traditional practices of the rural farmer descended from their ancestor, such as canal excavation, diversion weir, temporary diversion structures and rotational water distribution and so on, and yet still practiced today. Particularly for tunnelling technology, most often are only discovered on the lesser islands, such as Bali and Lombok Islands, and few cases on Java Island, though Sumatra Island also has some. The reason of the tunnelling application for irrigation on these particular islands is perhaps due to the specific arid and semi-arid climatology and geographical zones on top of the proper geological structure for tunnel construction. For other tropical zones at the major islands, such as Sumatra, Java, Kalimantan, Sulawesi and Papua Islands, the agricultural lands are mostly at the lowland plain, on top of the effect GANY - INACID 6


Irrigation Tunneling

in Ancient Indonesia

of the tropical rain, in which irrigation water requirement are not crucial compared to the Lesser Islands which are located at the arid and semi arid zones. Therefore only the cases of these areas will be discussed in this book, with some example from other region of the country. 6 CHAP1General illustration of the zone location of tunnels: In most cases, the general condition of the tunnel location on Bali, Lombok and Java islands are almost similar, in the sense that the area are consisted of arid and semi arid zones, undulating, hilly and are frequently suffered from water scarcity. Bali Island: For the case of Bali for instance, the area are consisted of mostly semi-arid zone particularly on the northern zone of the Island. Similarly, Lombok Island which is located at the next eastern of Bali Island, the southern and eastern parts of the islands are mostly arid zones and often suffered from water scarcity even during the rainy season. The total area of Bali Island is only about 5,600 km2, with a total of scattered small irrigation schemes covering about 100,000 ha, of about 20% of the total area of the island, others consisted of secondary forest, hilly upland areas, villages and hamlets for residential areas. Lombok Island: Lombok Island as another location of tunnelling practices is the immediate neighbouring island in the eastern of Bali, which is part of the West Nusa Tenggara Province. During the Colonial Era, Bali and Lombok Islands was under one Regional (kresidenan) Government Administration (Authority). The geographical characteristic of Lombok Island is divided into three regions namely North Central and South Regions. North region is characterized by mountainous 7 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

area with category from very steep, steep and narrow plain on the coastal zones. Central region’s topography is relatively flat, the eastern area consist of water stressed area. While South Region, consisted of undulating and flat area, but mostly are at water stressed area with low rainfall. The total irrigated area of Lombok Island is 120,830 ha. Majalengka District, West Java Province: Other special case of tunnelling on Java Island is located at Cikarag, Bantarujeg, Kabupaten Majalengka West Java Province. Kampung Cikarag is remotely located behind Mount Lamping. This village, one of the rural areas in Kabupaten Majalengka, lies about 12 km from the district capital Banturujeg. The connection between the two places is only minimum and only useful for small vehicles in dry seasons. The location is similar to Bali and Lombok as the water stressed area on West Java. Most of its people earn their living from growing seasonal crops with some perennials in their generally-small strips of gardens as means of obtaining additional income. The hilly nature of Cikarag’s topography forces the local farmers to use their best efforts in cultivating the crops, either in rice field or in the narrow strips of garden. Tasikmalaya District: Other case lies at Neglasari, a remote village in the southern slope of active volcano, Mount Galunggung, about 74 km from the capital town of Tasikmalaya District. During the dry season, Neglasari village is easily accessible by two wheel vehicle, and four wheels vehicle as well, but the road has not been paved by asphalt pavement and mostly are under the severely damaged condition. The hilly and undulating nature of Neglasari’s topography forces the local farmers to use their best efforts to cultivate crops, either in terms of rice field or in the narrow strips of garden. GANY - INACID 8


Irrigation Tunneling

in Ancient Indonesia

CHAPTER II

TUNNELING PRACTICE IN BALI ISLAND The tunneling practice in Bali is part of the Subak practice for transporting water for irrigation from the water source to irrigation system, which is an ancient irrigated-agricultural practice of the Bali Island, Indonesia (See the General Map of Bali Island blow). Like most irrigation schemes in Indonesia, the Subak system also serves small land holders where lowland paddy monoculture is practiced in majority. According to R.Gory (in Gany, 1975), paddy irrigation has been practiced in Bali for more than one thousand years. The early monograph of R. Gory stated that there are some evidences suggested that irrigation in Bali has been existed since 600 AD. Since that era, the farmers in Bali were very skillful in excavating and constructing irrigation tunnel across the high ridges or high lands.

Figure 2.1. General map of Bali Island 9 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

The topographical conditions at the central part of Bali are mostly consisted of steep and undulating, dominated by river tributaries. The soil layers are mostly consisted of volcanic soil and gravels, except at the southern range which consist of limestone layer. Most of irrigated agricultural areas are located at the south plain with some minor parts are located at the northern area. Since the areas are mostly of steep topography with small river tributaries limited water discharge during the dry season, so weirs are mostly constructed at the low lying areas in order to be able to tap the water for irrigation, and therefore, most weirs are set up at higher level. Accordingly, conveyance canal should be constructed across the hill or set up along the steep valley. Such close conduit canal or tunnel referred to as “Awungan� in Balinese term. In most cases, tunnel or awungan in local language are functioned as fore-channel at the main canal, except some cases at the hilly terrain. For more illustration, see Figure 2.2., Typical layout of irrigation networks and tunnel as fore-channel irrigation networks in Bali. It is estimated that the total length of close conduit tunnel in the entire Bali Island is at least 100 km (1979), at present 300 km including close conduits (PU Provinsi Bali, 2009), and the District of Gianyar has the longest total of tunnel at about 30 km. The Petanu Irrigation Area with the total irrigated area of about 2,015 ha, has the longest tunnel, at the total of 9,456 meter – consisted of Sukawati Tunnel at 5.00 km and Gunungsari tunnel at 4,456 meters (Suadnya, 1981). During the ancient time, land surveying was still utilising simple local technology however, today the recent development of land surveying, the ancient technique can be improved toward a more precise results effective and efficient implementation. However, there are GANY - INACID 10


Irrigation Tunneling

in Ancient Indonesia

some techniques that are still relevant to the developed technology adapted today.

Figure 2.2. Typical layout of irrigation network and function of tunnel as fore-channel irrigation networks in Bali

11 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

For instance, the straight alignment technique by using bamboo wickerwork’s is still relevant on making straight alignment of the tunnel. For small size tunnel, manual work is still relying simple tools such as pickaxe, hoe, and so on, is still use effectively. Electric light can now be used instead of kerosene oil lamp inside the tunnel for excavation. Traditional tunnelling for irrigation, in fact was still using the very simple technique. It is therefore, interesting to know how the ancient generations were managed to employ such a simple technique for tunnelling in line with the chance to improve the technique using modern technology land and geological surveying and the likes. Irrigation systems with tunnel are widely used in Bali for optimizing alleviating the capacity of the farmer to develop efficient and almost free maintenance technique in comparison with open channel for instance. The farmer are now capable of making a shorter and straight forward canal, in comparison to open channel through the long alignment or through the long contour line, after all difficult to maintain the sustainable application. Considering the undulating topographical condition in Bali, an average of about 15% of the length of the main canal and secondary canals consisted of close conduit channel such as tunnel. Considering Bali as the famous cultural centre, and tourist destination, also the development much related with agricultural tourism, with specific Balinese heritage then irrigation system with traditional tunnelling would enrich cultural practices. The fact that the farmers in Bali only inherit tunnelling technology from generation to generation the tunnelling experience so far is only descended to the next generation through practical experience. In fact, many ancient types of equipments are kept in Subak Museum in Bali, but GANY - INACID 12


Irrigation Tunneling

in Ancient Indonesia

most of them without detail notification about the historical aspects related to tunnelling activities in the past. This book at least provide additional information concerning the history of tunnel in Bali which is relevant to the areas similar to Bali, that are still available in many regions in Indonesia, even perhaps in other tropical regions. Meanwhile, this tunnelling system has already had a long development history from generation to generation since the old days, and still relevant with the present circumstances. Information and data in the preparation of this book are mostly based on field observation with some field notes and unpublished reports of irrigation staff. Some information was obtained from the local traditional foremen whom are mostly retired and non educated practitioner). From the retired irrigation staff, be known that since 1977, an effort has been pursued for initiating the effort to write book about tunnelling technology. However, so far there are not so many data and information available about this. The writer hopes that the information in this book would give comprehensive idea about tunnelling technology in Bali and Lombok Islands in particular, and other similar regions in general.

2.1. Basic Philosophy of Organizational Arrangement The working arrangement of farming activities in Bali Island, including construction of Tunnel has been generally based on traditional organizational arrangement, by taking the natural mechanism of human body into consideration, and converted into the rationale of group membership on the basis of “togetherness” or mutual aid principle referred to as “gotong royong” principle.

13 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

The main principle built into this system is based on the ability to regulate the suitable techniques, time, space and environment in order to meet the livelihood of the people through "harmonious-togetherness" principle. The underlying approach is based on the ability of maintaining a proper balance, and the ability of acquiring harmonious relationship between human, the Creator (God), and nature on reciprocal basis (Trihitakarana philosophy). The basic techniques are incorporated with the simplicity principles, so that every members of the community are able to adopt and/or apply the technique without involving sophisticated learning process. Despite the fact that the Subak system – Subak in Bali is only a system, but also as irrigated agricultural organization (See Box 1) – and its practices were invented and evolved since long time ago, it is quite amazing to know that much of their techniques are still convertible and/or adaptable to the modern practices that the people understand today. In spite of its simplicity principle, however, the more we can comprehend the traditional irrigated-agricultural practices in Subak system the more we learn about their technicalities. As a matter of fact, there is a reason to believe that the traditional agricultural practices adopted by the Subak organization were based on systematic observations. Whoever might be the inventors, they must have been understood the participatory principle of the traditional organization of the ancient farmers, the technique must be translated into the comprehendible sense by the traditional farming community. Otherwise, they will not be able to participate if the technique is involving too sophisticated learning process by them.

GANY - INACID 14


Irrigation Tunneling

in Ancient Indonesia

BOX 2: SUBAK SYSTEM IN BALI

The Subak system is an ancient irrigated-agricultural practice of the Bali Island, Indonesia. This system serves small-scale land holders where lowland paddy is mainly practiced. The exact date of Subak was not known, however, the most recent evidence suggested that the Subak system was believed to have been existed in 800 of Saka Calendar or in 882 AD. Learning from agricultural practices of the Subak system, it is apparent that the system has been established to meet the farmers' demands through a togetherness approach among it members. The main principle built into this system is based on the ability to maintain proper balance, and harmonious relationship between human and nature on reciprocal basis. The basic techniques are incorporated with the simplicity principles, so that every member of the community can adopt the technique without involving sophisticated learning process. Although the Subak system and its practices were invented long time ago, much of their techniques are still convertible to the modern practices that the people understand today. In fact, there is a reason to believe that the traditional agricultural practices adopted by the Subak organization were based on systematic observations. Today, despite the underlying irrigation development and management practices in modern Indonesia, there remains a lot more phenomenon of ancient agricultural practices – demonstrated as an example by the Subak System – that need to be uncovered in an attempt to contribute practical technicalities for implementing sustainable irrigated agricultural development under the small farming circumstances. (Source: Gany, 2002. “Subak Irrigation System in Bali”).

Board of Organization: For arrangement of working performance in accordance with organization demand, the board of organization (which is democratically elected by the member of water user organization) would determine the working assignment, base on the function of each working group, based on the rationale of working mechanism of human body. See Figure 2.3., Basic principle of working mechanism adopted by the organization. The members will conducts the mutual aid performance based on the arrangement and assignment of the Board of Organization.

15 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

From Figure 2.3., it is clear that the leader of organization is associated with human head which has the function to think, coordinate, manage and control the organizational activities.

Figure 2.7. Basic Principle of working mechanism

Down to the second layer, assistant to the leader will have the responsibility to process the strategy for decision making by the leader, and eventually at the third level, the GANY - INACID 16


Irrigation Tunneling

in Ancient Indonesia

executor together with the member of organization will implement the program. Thus, assistant to leader is associated with the function and human body and, and the executor is associated with leg and hand which perform the implementation performance toward a certain output. So, this principle applies to all kind of livelihood activities including construction of tunnel. Especially for tunnel design and construction implementation, there are certain experts by experience and by heritage, often referred to by them as “witch engineer� (undagi) who helps the activities irrationally, but mostly successful in their work. Physical Measurement: Given the fact that during the old days, people are still do not have exact measurement standard, the community members are using the human body organ for determining the size, distance or length of things.

Figure 2.4. Measurement of length by human organs

17 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

So for ancient irrigation technology, they are mostly using the non exact size as we do today. Even now, the traditional measurement is still utilized by the traditional farmers, though the modern standard of measurement is given to them. See Figure 2.4., the measurement which were adopted by the traditional technique, and till today the measurement are still utilized for non precise measurement. 2.2. Equipments, Tools and Facilities Equipments, tools and facilities refer to in this session are merely for traditional tools that are used by tunnel builders during the ancient time, including tool for design, land surveying, tunnel excavation, as well as for operation and maintenance. Also, the process of making land surveying and levelling equipment from traditional materials, bamboo, timber and rope made of palm fibres. For tunnel construction, besides using the natural human body organ such as eyes, hands, legs, and others, there are several other important traditional tools and equipment which were used by them. In this regards, illustration of equipments, tools and facilities for tunnel construction during the ancient time will be given in four categories: (1) Tools for preparing the related equipments; (2) Equipment for calibrating the prepared equipment (Alat uji “Peganjing�); (3) Land surveying equipment; and (4) tools for tunnel excavation. Tools for preparing the related equipments: The tools refer to this session are all the tools and gadgets that are utilized by witch engineer (undhagi) for preparing the related survey, land surveying equipment for tunnelling. See Table 2.1., tools for preparing equipment for tunnel construction.

GANY - INACID 18


Irrigation Tunneling

in Ancient Indonesia

Table 2.1. Tools for preparing surveying equipment

No.

Tools

Number

Remarks These tools are actually required fro the undhagi to make traditional survey equipment

1. 2. 3. 4.

Chisel Small saw Small plane Ruler (seleran)

4 1 1 1

5. 6. 7. 8. 9.

Pincers Knife Grinder Pencil Sand paper

1 1 1 1 -

Calibration Equipment: These tools are facilitated for calibrating the level of appropriateness of the survey equipments that are made. These tools are listed in Table 2.2., below (See also Figure 2.5., “left” and Calibration “right”). Table 2.2. Calibration equipment No

Tools

Number

Remarks

1

For accommodating water

2. Bamboo ruler

1

For measuring the head between water level and the bottom of survey equipment

3. Level ruler

1

For hanging the level

4. Brocken-up bamboo

2

For handling the level equipment

1. Earthen water container

19 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 2.5. Calibration equipment (left); and the undhagi demonstrate the calibration process (right).

The undhagi tests the level of appropriateness of the level as follows: (1) The earthen container is filled with water such that it adequate for showing the water level; (2) Two pieces of broken-up bamboo are pegged down for extending the center line of the level to be tested; (3) The two ends of the rulers are tight at the pegged broken up bamboo such that both are parallel with the water level by setting the ruler up and down. The level that is going to be tested is put at the top position, the vertical position of the skein with the water level, in which the string is lined with the intended direction, which is at the upper level of the equipment and the needle position is in line with the bottom position. If the position of the skein is already the same as stated above, then the lower part of the level is measured to its distance with the water level. As both ends of the level are similar with the distance from the water level this meant that the level equipment is appropriate and can now be used. If not, then it must be corrected again, and GANY - INACID 20


Irrigation Tunneling

in Ancient Indonesia

the mistake may take place if the needle position is not vertical with the lower part of the level equipment (level bar). This procedure is actually very simple now, because the undhagi may use small plastic hose which was not yet available in the old days. Land Survey Equipment: The land survey equipments refers to in this session are those equipment that used by the undhagi for tunnel to conduct land surveying for tunnel construction or open canal: (1) Equipment to be used at the ground level; (2) Equipment to be used below the ground level; and (3) Survey equipment to be used for open canal. For land surveying equipments at the ground level there are two types namely: Peganjing duhur, for measuring the different level of two points at the ground level. Stakes are needed for determining the straight line at certain direction. Peganjing duhur: Is a set of survey equipment consisted of: a). Two peep holes (corong) made of strong timber with hole at the size of 5 x 5 cm. This peep hole consists of 3 holes; two holes functioned as sight alignment and one hole which are formed after set up at the base of vertical peep hole (petibak) with the size of 4 x 0.15 cm, functioned as vision tube; b). One set of Petibak, is functioned as the base of vision hole. (See Figure 2.6.)

21 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 2.6. The details of the pengajing duhur survey equipment.

At the bottom part of this petibak there are two holes with the diameter of about 1 cm and the depth at about 1 cm, which is meant as the hole for holding the base of the pale on the tripods, so that this petibak can be turned around. The length of this petibak is about 50 cm with the size of 7 x 8 cm; the tripod is function as the base for setting the GANY - INACID 22


Irrigation Tunneling

in Ancient Indonesia

equipment at vertical position; the tripod height at the set up position is about one meter; c). The horizontal level (peganjing) is used to set up the horizontal position of the petibak so it would become perfectly horizontal and vertical with the earth axis; d). Three bamboo stakes with the diameter of 5 cm is required to make straight line.

Figure 2.7. The picture pengajing duhur survey equipment (made of bamboo), kept at the Subak Museum Tabanan Bali

Underground Survey Equipment: This survey equipment refers to the apparatuses that are used by the surveyors at the underground construction or excavation of the tunnel (in side of the tunnel during construction). This equipment consists of one unit refers to as 23 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

“Peganjing dasar� for measuring the tunnel slope or levelling. (See Figure 2.8., and Figure 2.9.).

Figure 2.8. The sketch of pengajing dasar survey equipment for measuring the slop or tunnel leveling

Figure 2.9. The undhagi (left) demonstrate the use of pengajing dasar survey equipment for measuring the slop of tunnel. Prototype of pengajing dasar kept at Subak museum, Tabanan (right).

Survey equipment for open channel: This equipment consists of two bamboo bars at the length of 40 cm and a petibak (timber bar) with the cross section of 6 x 4 cm and with the length of about 50 cm. This equipment is used to GANY - INACID 24


Irrigation Tunneling

in Ancient Indonesia

measure the straight direction of the open channel alignment (See Figure 2.10.).

Figure 2.10. The undhagi (left) demonstrate the use of survey equipment for measuring the straight alignment of open channel. This survey equipment kept at Subak museum, Tabanan, Bali (right)

Measuring the topographical level: For measuring the difference of level between one spots to another, they use the traditional “Peganjing Duhur”, which is almost similar to surveying technique today (Figure 2.11., and Figure 2.12.). The distance between one spots to another for proper measurement (based on experience) is considered to be between 1 and 20 meter.

Figure 2.11. The measurement of the difference of level between one spots to another by using “pengajing duhur”, which is almost similar to the present technique

25 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 2.12. The undhagi (left) sets the pengajing duhur survey equipment before surveying the level difference. Prototype of survey equipment kept at Subak museum, Tabanan, Bali (right)

Measuring the river depth: For measuring the depth of water at the river, they use the simple procedure as the technique we are using today; except that they are using simple equipment which is not as perfect as modern equipment today. In addition to the simple equipment and technique they are using, they are not yet familiar with the measurement standard. Most important to them is that the water at the tunnel can flow for irrigating the land at the lower place than the water level at the water source in the river. (See Figure 2.13., measurement of the depth of the river and the level of the surface to allow the water flow to the downstream of the channel. And most important, that they can also determine the height of the weir they will be constructing.

GANY - INACID 26


Irrigation Tunneling

in Ancient Indonesia

Figure 2.13. General sketch of the measurement of the height of the water and height of the water level, so they can decide the slope of the tunnel and the height of the weir they plan to make.

From Figure 2.13., above, it is obvious that the sensitivity of the level measurement equipment, will determine the appropriateness of the survey result, especially that the bamboo material they are using as stakes, are not straight and also will not meet the flatness of the timber plank. 2.3. Planning, Designing Staking Out Preparation As far as the historical evidence is concerned, it is believed most obviously that the planning and design of tunnel is believed to have been on the trial and error only, though many person belief that there some traditional experts in the community who have extrasensory perception about the tunneling technology by birth. This kind of personality is conducting their works through instinct from within. In case the farming community asked him to guide the planning or design of irrigation infrastructure, they will 27 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

visit the location and contemplate thinking about the possibility to design and subsequently to conduct the construction implementation. As he started to think the idea, he may make some follow up survey to make sure that the tunnel could be made at certain alignment and subsequently to find adequate head for discharging the water to irrigated land beyond the outlet of the tunnel. If this is the case, they will discuss with the community leader about the possibility, and subsequently discussing the way the infrastructure would be conducted by the farming community members. Despite the uncertainty of the design, the community in reciprocal respect will trust the capability of the traditional engineer to arrange the work, and will follow whatever obligation they will have from the technical work design. If such consensus has been reached, the construction design will soon be started with surveying the tunnel alignment, followed by determination of the size of the tunnel, as well as staking out the tunnel intake, alignment and outlet. In such case, there is no data at all concerning hydrology, topography, geology or soil structure, irrigation areas, all are determined through instinctive trial and error approach.

A. Land Surveying for Determination of Tunnel Alignment As the location of the intake of the tunnel decided, the land surveying will start by drawing straight line toward the direction of the tunnel up to the outlet. The way they conduct the tunnel alignment could be illustrated as the following figure (Figure 2.14., Schematic diagram of the Measurement of the tunnel layout).

GANY - INACID 28


Irrigation Tunneling

in Ancient Indonesia

Figure 2.14. Schematic longitudinal diagram of the land survey for determination of the measurement of the tunnel layout across the hill (munduk)

Along the tunnel alignment at the ground surface, they set up bamboo stakes at certain distance to form straight line. The direction of this tunnel alignment is set up from the point of tunnel outlet (kibul) up to the river bank across the proposed tunnel intake (bungas). Along the straight alignment at top soil (munduk) across the river, another straight line is drown by using string in line with the tunnel alignment across the river in which the axis of the tunnel intake (bungas) will be determined. From this point on, the tunnel excavation will be started. By making a straight line from the point to be decided across the river parallel with straight alignment along the ground surface it means that the tunnel direction would be at the same direction with the straight line at the ground surface. With the guidance of the aeration holes, then the inside tunnel axis would be under the proper control. To make sure that the axis of the tunnel is setup at the right direction and with consistent tunnel size, based on the decided measurement, the cross-section profile will be 29 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

used as reference for staking-out (See Figure 2.15.) and subsequently as reference for actual field construction implementation.

Figure 2.15. Schematic reference for tunnel alignment and cross-section for staking out of the actual field implementation

B. Determination of Tunnel Size As previously mentioned that during the old days, people are still not having exact measurement standard, the community members are using the human body organ for determining the size, distance or length of things. This also applies for sizing of the tunnel cross-section. Given the fact that the topographical condition of Bali Island are mostly consisted of hilly upland and undulating trend, so the acreage of irrigation areas are mostly of small and medium sizes types, (300 to < 5,000 ha), so the design of canal discharge will adjust this condition, and hence size of tunnel will also determined accordingly.

GANY - INACID 30


Irrigation Tunneling

in Ancient Indonesia

General Principle of Discharge Design: Considering the estimate of water requirement, the water discharge is estimated by the size of land plots and estimate of the amount of rice seed which will be required for particular land plot. In most cases they use tektek size, which refer to the amount of water on continuous flow basis, the amount of seed to transplant, as well as the estimated area of the land plot. Under the Subak system, the water distribution system is conducted by the farmers themselves through the elected representatives. The water distribution pattern is based on a certain water requirement consideration as the following: (1) the water delivery is assigned to the farm land on plot-by-plot basis; (2) each individual plot with a seed requirement of one tenah of paddy seed per plot, is called tek-tek unit area; each area covers by a farm plot of one tek-tek unit is measured by a traditional standard of water measurement device. The farm plot water requirement is determined by the amount of seeds of paddy that is planted in a certain size of farm plot â&#x20AC;&#x201C; refers to as sesukat which is called Tek-Tek. The amount of seed requirement for each te-tek unit is called tenah which is comparable to about 25 to 30 of grain paddy. Tek-tek is the Balinese term which is literally meant as to cut one thing into small pieces. Thus, each of the tenah seed unit is translated into tek-tek unit of farm area; the unit area is further converted into a certain magnitude of water measurement. This water requirement unit is also called tek-tek. The water measurement device is usually made of a piece of timber or log, cut at the desired length with a cut-off grove for measuring the water flow. The size of the cut-off grove of one tek-tek unit, for instance, is measured in terms of ordinary human finger thickness, about four fingers width 31 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

and one finger depth, which is comparable to about 8 cm width and 2 cm depth (see Figure 2.16., for illustration).

Figure 2.16. Typical tektek water measurement device

For larger farm plots, the size of cut-off is determined by multiplying the single tek-tek standard illustrated above, proportional to the size of the command area. Thus, one tenah of seed or one tek-tek unit area will get one tek-tek unit requirement of water. The water requirement for larger area is served in terms of multiplication of the one tek-tek water flow standard. So, the determination of discharge will be based on this method of discharge estimation, and hence the size of tunnel cross-section. (See Figure 2.17., Traditional measurement (kilan) for each unit of tektek Picture of tektek water measurement device). And Figure 2.18., typical figure of tektek water measurement device, based on measurement of land area to be irrigated. GANY - INACID 32


Irrigation Tunneling

in Ancient Indonesia

Figure 2.17. Typical tektek water measurement device

Figure 2.18. Typical figure of tektek water measurement device, based on measurement of land size to be irrigated

33 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Determination of Cross-section: Beside the large area to be irrigated (water discharge) and the length of tunnel to be constructed, the size is also considered by the capacity of the farmers to provide for the required potential (physically and financially). In practice, however, there are varieties of tunnel cross-sectionâ&#x20AC;&#x2122;s sizes. Most specifically the size is usually grouped into three sizeâ&#x20AC;&#x2122;s categories, these are: small size; medium size and large size. To simplify the standard the three categories are often expressed in traditional way: (1) crawl type; (2) squat type; and (3) standing type, taking into the size of human body to work freely inside the tunnel, for excavation and later for maintenance. (See Figure 2.19. a, b, and c, for further illustration).

Figure 2.19.a & b. Left, is the crawl type, and right is the squat type measurement

GANY - INACID 34


Irrigation Tunneling

in Ancient Indonesia

Figure 2.19.c. The standing type measurement standard

From Figures above it can be seen that despite the non exact standard they are using, the most important principle, that they still accommodate the safety factor by allowing additional samusti (one fist or about 7cm) at the horizontal tip, and one pengurip at horizontal tip for accommodating the differentiation of human sizeâ&#x20AC;&#x2122;s organs, and therefore to accommodate the large person to enter and work at the tunnel.

35 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Aeration Hole: In order to allow proper air circulation and to facilitate the disposal of excavation material, they make aeration hole (calung) at certain distance based on local conditions. For horizontal location, especially if the horizontal distance is quite short from the side valley. They also make the same aeration hole (bindu), especially for the local condition where the horizontal distance from the side valley is too long. In some practice, the aeration hole is made as certain interval depending upon the local need for air refreshment or for extra lighting. Often, aeration was made at certain interval when the tunnel is made parallel with the river or valley direction. The excavation disposal therefore is easily transported out of the tunnel rather than transporting the excavation material along the tunnel layout. The minimum length of the aeration hole so far is set up at the minimum of 6 meter from the tunnel axis. Depending upon the soil types at the bank of the valley. The aeration hole will be longer if the soil condition is not conducive to close conduit, otherwise, it can be replaced with vertical aeration hole or bindu in local language. See Figure 2.20., the tunnel lay out with the location of horizontal as well as vertical aeration hole at the tunnel of Tukad Pangiangan Irrigation Scheme. Some aeration holes are designed for side spillway hole, during the operation and maintenance activities of irrigation scheme.

GANY - INACID 36


Irrigation Tunneling

in Ancient Indonesia

Figure 2.20. The tunnel lay out with the location of horizontal as well as vertical aeration hole at the tunnel of Tukad Pangiangan Irrigation Scheme

37 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

For the case of Tukad Pangiangan Irrigation Scheme, the tunnel has been used for at least four functions: (1) As the transportation facility to go in and out the tunnel for construction; (2) As the facility to provide natural light from outside; (3) As facility for circulation of fresh air; (4) As the facility for technical inspection during and after construction; (5) As disposal hole for groundwater and excavation material; and (6) some function as side spillway for excess water during O&M stage. See Figure 2.21., A, B, C, and D. Pictures of typical aeration holes.

A B

C D Figure 2.21. Pictures to show the general example of typical aeration holes with different functions, A = for inspection, B = horizontal air circulation, C = side spill way for excess water; and D = vertical aeration hole for lighting and air circulation

GANY - INACID 38


Irrigation Tunneling

in Ancient Indonesia

Coconut Oil Fuel Lamp for Lighting and Fresh Air Indication: Due to the fact that the battery lighting and electricity lighting was not available during the old days, therefore for lighting inside the tunnel during tunnel excavation, coconut oil fuel lamp were used. Some of the tunnel builders decide the necessity to make aeration hole at the certain distance when they found the intensity of the light significantly decreasing, and can no longer maintain the regular air circulation for the coconut lamp. When they make aeration hole, with appropriate air circulation, they found that the intensity of the lighting become normal again. The lamps usually place at the notch they make at regular distance along the tunnel so the light will be distributed along the tunnel they currently work. (See Figure 2.22., Cross-section of the tunnel and the notch (groove) for placing the coconut fuel lamp lighting).

Figure 2.22. Cross-section of the tunnel and the notch (groove) for placing the coconut oil fuel lamp lighting

39 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Beside the light indication, other considerations are also made to determine the distance of aeration hole, this include: 1) Air condition at the tunnel; 2) Number of workers; 3) Soil condition (soil types) bad odour or smell, etc; and 4) Topography. In general the distance between one aeration holes to another is normally between 100 and 200 m. However, there some case where the distance is set up at 600 m. For aeration hole with the distance of 100 to 200 m, number of workers is limited to 6 persons, while the distance of 600 meter can accommodate between 12 to 15 workers simultaneously. For tunnel construction at the undulating topography the distance between aeration holes to another is usually shorter to allow appropriate control of alignment.

Determination of Bottom Slope of the Tunnel: In order to secure the water flow by means of gravity, the bottom slope is usually decided through experience, depending upon the soil material and the magnitude of the water discharge and the sediment transport. Base on experience, the tunnel builder already know the flow category such as supercritical, critical and laminar in local terminology. In Bali in general the undhagi and local technical person are mostly aware of the characteristic of water flows which are associated with the slope of the tunnel base. The local flow characteristic is categorized by the Balinese practitioner as elaborated in Table 2.3., below:

GANY - INACID 40


Irrigation Tunneling

in Ancient Indonesia

Table 2.3. List of flow characteristic base on traditional Balinese Experience No.

Name of flow category

Slope

1. Jaran Ngarong

0.01 < I <0.015

Buaya mangap 2. (similar to wild crocodile)

0.005 < I ≤ 0.01

3. Sikep Ngimbang 0.0025 < I ≤ 0.005

Brief Remarks No sediment deposit Small gravel can settle as deposit Sand is potentially deposited

Mebulun jangkrik 4. (similar to the I ≤ 0.0025 vibration of cricket wing) 5. Banyu Langse

Vertical

The case of water fall either on natural flow or at the diversion

For determination of the tunnel slope, after knowing the head between the weir location and the highest elevation of land to be irrigated, the flow characteristic could then be anticipated. If the slope is considered too steep with higher head, then the weir location can be reconsidered whether to move further downstream to find the least steep slope or to rectify the slope, in order not to protect the damage of the tunnel resulted from the occurrence of supercritical flow.

41 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Documentation: Despite the traditional practice, one of the unique features of tunnel design in Bali Island is that the documentation is always made by the designer in order to communicate the feature of the tunnel to others, especially for the subsequent operation and maintenance purpose, as well as for future rehabilitation or even for reconstruction purpose. The simple record is written down in bamboo pieces by using local Balinese traditional script. See Figure 2.23., Documentation of tunnel features written at pieces of bamboo.

Figure 2.23. A picture showing documentation of tunnel features written at pieces of bamboo, which is currently kept at Subak Museum in Tabanan Bali

2.4. Construction (Excavation) of Tunnel The excavation of tunnel referred to as â&#x20AC;&#x153;ngawungâ&#x20AC;? in Balinese term, is the entire process of making tunnel from the staking out and the beginning of excavation till the tunnel ready for utilization.

GANY - INACID 42


Irrigation Tunneling

in Ancient Indonesia

After the whole preparatory works including design, surveying and preparation of equipment completed then the tunnel construction or excavation will be conducted. The beginning of construction work is usually conducted with special ceremony referred to in Balinese as â&#x20AC;&#x153;Ngendagâ&#x20AC;? (beginning) Ceremony with its series of ritual processing. Construction Equipment and Facilities: All equipments and facilities that are utilized for tunnel construction consisted of simple traditional tools, equipments and facilities. Most notable thing is that they do not use any supporting materials like scaffolding or supporting structure for the ceiling for preventing the land slide during construction and operation and maintenance. Thus, they only relay the soil structure to keep supporting the weight of the soil from the top of the tunnel ceiling. See the list of tools, equipments and facilities in Table 2.4., and Figure 2.24. A, B, C, D., and Figure 2.25., below for further detailed illustration: Table 2.4. List of construction equipment and facilities

4.

Name of Equipment Purpose and Facilities Peganjing Dasar To measure the slope of (Slope level) tunnel bottom Panyong (pickaxe) To excavate hard soil Udud (ordinary To dig ordinary soil pickax) Prapen (fireplace) Fire squirt (blower)

5.

Benang (string/yarn) String (yarn)

6.

Patok (wooden peg) Wooden Peg

7.

Seleran (ruler)

No. 1. 2. 3.

43 GANY - INACID

To extend straight line


Irrigation Tunneling

No. 8. 9. 10. 11. 12. 13.

Name of Equipment and Facilities

in Ancient Indonesia

Purpose

To shovel and Sodo (bamboo shovel) accommodate soil excavation Seperangkat To place and transport the keranjang tegenan soil excavation out. (bamboo basket) Gedeg dilabur putih To reflect the sun shine into (white painted woven the tunnel bamboo) Sembe (penyembean) Indicator for showing (Survey equipment direction for direction) Sepat gantung Hanging lamp for straight (hanging coconut oil lining the tunnel axis lamp) (minimum 3 unit) Linggis, (crowbar) For digging the hard soil or etc. gravel.

GANY - INACID 44


Irrigation Tunneling

in Ancient Indonesia

A

B

C

D

Figure 2.24. Some traditional tools used for tunneling, kept at Subak museum, Tabanan, Bali. A = pickax for hard soil and rock excavation; B = ordinary pickax for ordinary soil; C = Slope level; and D = Ruler and 90 degree guide

Figure 2.25. Some traditional tools used for tunneling, kept at Subak museum, Tabanan, Bali (left); and a fire squirt (blower), for maintaining the steel tools during operation (right). 45 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Excavation of the tunnel usually implemented with the guidance of highly experience person with the help of ordinary worker, and usually regarded as training ground for young (newly involve) worker. Along the execution of tunnel construction, the leader of the group always make regular checking on the measurement, direction, slope, health environment, as well as lighting and air circulation, especially when the distance is already reached the need to make calung of aeration hall. Similarly, the leader of the group always makes sure that the excavation work is conducted properly in the sense that the use of equipment is suitable with the soil or rock condition along the tunnel alignment. Also keep monitoring the groundwater flow as well as soil crack, and immediately take action if necessary. See Figure, 2.26., showing the picture of workers who are working for excavating the tunnel.

Figure 2.26. Pictures showing the workers who are working for excavating the tunnel

GANY - INACID 46


Irrigation Tunneling

in Ancient Indonesia

2.5. Controlling the Straightness of Tunnel Alignment a. During tunnel construction, for controlling the straightness of alignment at least three plumbs (skeins) are required. By hanging three plumbs at the ceiling it is possible to check the straightness of the alignment. b. Also, they frequently use lighting from small lamp (sembe). The lamps are placed at the special grove along the straight line of the tunnelâ&#x20AC;&#x2122;s wall. c. If the tunnel is required to turn, the lamps are arranged to meet the intended direction of the tunnel. The lamps are mostly made of earthenware container called coblong, at the diameter of about 5-8 cm, with floating cotton wisp floating at the coconut oil. Beside the use of the lamps as lighting during construction they also use the light for controlling the direction of tunnel, in accordance with the light of the coconut oil lamps. d. Beside the use of lamps for lighting inside the tunnel during construction, they also used bamboo plaited mats painted in white colour to reflect the light into the tunnels which is being under construction. e. In some cases, the use of mirror is also effective to reflect sunlight into the tunnel. For large works the use of white bamboo plaited mats is considered to be more effective than the use of small mirror.

2.6. Length of Construction Period The length of construction period of the tunnel is highly dependent upon the soil type to be excavated, and the worker. The hard soil with stone for instance, would require longer time compared with ordinary soil.

47 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

For the case of Pangiangan Tunnel with hard soil, for instance, the excavation progress only at the average of about 4-10 cm per day with three persons, this is due to the hard and massive breccia tuff type of soil and rock. If the tunnel is excavated from two directions, the time to complete still take more than 10 years. Even some tunnels were said to be excavated from the young age till the worker become old enough before they could complete the work. This indicate that the spirit of the people in the old days to obtain water for irrigation were quite amazing that they need years even decades to complete the tunnel construction. Based upon experience, the medium sized tunnel with a group of 12 workers would have the time for excavation at about one meter per day, or about 3 years for the tunnel of one km length. The tunnel workers are mostly prefer the breccia tuff materials because this type of soil is very easy to excavate, beside it porosity to allow the water flow during the process of tunnel excavation. The excavation time often become longer than the average condition due to some problems such as the intervention of boulders or massive stone, soft soil, cracked soil, proceed with the wrong direction and so on. Especially for tunnel excavation at the undulating topography, it frequently occur the excavation with wrong direction, for instance at Sidembunut Tunnel as the south turning point. Another problem related to the tunnel at the sandy soil which often suffered from fall of pert of the ceiling or even collapsed with large size, such as experienced in the tunnel of Gerana Irrigation scheme.

GANY - INACID 48


Irrigation Tunneling

in Ancient Indonesia

Other case was experienced in Sukawati Irrigation Tunnel where the tunnel alignment was constructed across cracked soil. During the trial test, the water was not able to flow downstream, rather it flow through the cracked soil. These problems were found because during the time, the construction works were undertaken with simple equipment, and practically no facilities to detect the soil condition as well as geological characteristics. And so on. 2.7. Problems on Construction of Tunnel In general the implementation of tunnel excavation the executor often suffer from problems and constraints, among others: 1) Encounter with boulders at the tunnel alignment; 2) The axis of tunnel from different direction is not met at the same line; 3) Tunnel excavation along the soft soil; and 4) The excavation encountered with soil cracking and so on. The problems are mostly resolved through special efforts: Problem of boulder: When the excavation encounter with boulder, the way to resolve the problem often by removing the boulder from the location by slowly moving it step by step; in case the boulder is too large, the axis often moved around the boulder and linking it with the original axis upon the downstream direction of the boulder. The axis is not met at the same line: If the excavation encountered by the misaligned axis, the staking out will be recheck from the top soil and the straightness of the axis line. If the line was found inconsistent with the original line, then it should be rectified by adjusting with horizontal and vertical lines. The procedure would be repeated with some kind of iteration process until the alignment come to the same line.

49 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Problem of soil cracking: This problem is usually resolved by moving the tunnel alignment to appropriate location. But the alternative must be at the most effective location to avoid the elongation of the tunnel. Problem of soft and porous Soil: Problem of inappropriate soil quality is usually resolved by adding lime mixture for soil improvement, and also to fill the porosity with the finer sediment deposit. The tunnel excavation could also be conducted from two directional approaches which are from upstream and downstream at two predetermined aerial holes. The bottom slope is always rechecked by using pengajing dasar to make sure that the slope at the right magnitude.

GANY - INACID 50


Irrigation Tunneling

in Ancient Indonesia

CHAPTER III

TUNNELING PRACTICE IN LOMBOK ISLAND Lombok Island, the immediate neighboring island in the eastern of Bali, is part of the West Nusa Tenggara Province with the capital town of Mataram located on this island. During the Colonial Era, both Bali and Lombok Islands were under one Kresidenan Government Administration. The total area of West Nusa Tenggara Province is 20,177 km2, or about 1.05% of the entire Indonesiaâ&#x20AC;&#x2122;s land area. The overall population of this province in 2002 was 4,152,000 people with the average annual growth rate at about 1.82% within the period from 1990 to 2000. Based on the 2002â&#x20AC;&#x2122;s Agricultural Census, the province has a total paddy field at 184,638 hectares, consisted of 179,638 hectares of irrigated paddy fields, 33,839 hectares of rain fed paddy fields, and only 19 ha of lowland irrigated field. More than 65% of the total irrigated agricultural land in the province is located in Lombok Island. (See Table 3.1. for further information).

51 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Table 3.1. Irrigated paddy field area West Nusa Tenggara by irrigation type, 2002 No

Irrigation Type

1. Technical Irrigation

Area (ha) NTB Lombok Province Island 66,826 42,071

2. Semi Technical Irrigation

80,686

50,378

3. Simple/Village Irrigation

37,126

13,471

4. Ground Water Irrigation

NA

NA

5. Lowland Swamp Area

19

0

33,839 184,638

14,910 120,830

6. Rain fed Irrigation Total

Source: Agricultural Survey, 2002 Central Bureau of Statistic

The geographical and topographical characteristic of Lombok Island is divided into three regions namely North Region, Central Region, and South Region. North Region starts from the top of mountain extending from west eastward to the north coast. There area has three major mounts, Mount Punikan (+1,490 m), Mount Kondo (+2,946 m), and Mount Rinjani, which is the highest in the Island (+3,775 m). The topographic condition of the north region classified as steep and very steep with narrow plain at the coastal zone. Rainfall in this region is low in the western side and very low in the eastern side. Central region stars from the top of the above-mentioned mountain to the top of the low mountain lies in the central part of the island. The western part of this central region has high rainfall with the topographical condition relatively flatter than the northern region. The rivers flowing in the western side to the western are mostly having stable regime with GANY - INACID 52


Irrigation Tunneling

in Ancient Indonesia

much water resource potential. The rivers flowing in the eastern side to the southern and eastern coasts are mostly having lower water sources due to small rainfall. Therefore, development of irrigated agricultural land was mostly concentrated on the western part of the central region. The Eastern part of this central region also has a low water resource potential, but the topographical condition is fairly suitable for irrigated agricultural development. Southern region starts from the top of the low mountain (the boundary of Central Region) southward to the southern coastal zone. This region has a low potential of water source as it has very low rainfall. The introduction of technical irrigation system in Lombok Island started since the involvement of Dutch Colonial Government in irrigation development in 1916. The first irrigation development in eastern part of central region was started with construction of a weir in Palung River for supplying irrigation water to a command area of 2,400 hectares, and the second was ‘Gebong’ Irrigation System, both were constructed in 1919. After intensive irrigation development and management implementation, since 1937-38’s Fiscal Year, Lombok has exported significant amount of rice to other places in Indonesia and the Netherlands. It was recorded that in 1937-1938’s Fiscal Year alone some 46,600 tons of rice were shipped to other places from Mataram Harbor, of which some 23,000 tons was exported to the Netherlands. In 1920 a study was conducted for preparing a comprehensive water resources and irrigation development planning. The study concluded identification of potential development as the following: i) The Potential land in the central region of the island amounting to 53 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

43,000 to 50,000 hectares; ii) The western part of central region has a substantial amount of water sources; with potential of inter basin water transfer from west to eastern region; iii) Considering the traditional irrigation practices the potential water transfer from west to eastern region, could only be done by upgrading the existing Subak irrigation schemes from simple to technical systems for the more efficient water use, and hence, the excess water in the western region can be transferred to the eastern region. See Figure 3.1., the general map of Lombok Island.

Figure 3.1. General map of Lombok Island.

The tunneling practice in Lombok Island is actually later than of the Subak practice in Bali for transporting water for irrigation from the water source to irrigation system. Most of the techniques for construction are using similar GANY - INACID 54


Irrigation Tunneling

in Ancient Indonesia

application of tunneling practice as in Bali Island. In addition, the planning much more simple, which in fact, mostly relying to the local practice similar to witch engineer using instinctive extra sensory perception to implement â&#x20AC;&#x153;planning as-you-go principleâ&#x20AC;?. So far there is no record or written documents concerning tunneling practices available in Lombok. In addition, there were no more successors of such traditional tunneling professionals after they passed away. Thus tunneling technique in Lombok Island had just disappeared within the last few decades. There are, however some traditional tunnels which are still in good operation today after improvement by the government but still operate and maintain by the local water user association. Sindang Gila Traditional Tunnel: The Sindang Gila Tunnel is located at the village of Senaru, District Bayan, West Lombok District with the distance of about 70 km from Mataram, the Capital City of West Nusa Tenggara Province. (See Figure 3.2. Lay out of Sindang Gila).

Figure 3.2. General layout of Sindang Gila Irrigation Area

55 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 3.3. General condition of irrigation area, currently served by Sindang Gila Tunnel

This tunnel has a length of only 600 m but quite unique because it locates along the steep slope with hard rock and breccia tuff based alignment. The total potential irrigation area served by the tunnel is 855 ha with the functional irrigation area of 496 ha. The unique feature of the tunnel is that the planning and design was only conducted on the basis of "plan-asyou-go" approach by two â&#x20AC;&#x2DC;witch engineersâ&#x20AC;&#x2122; utilizing the power of instinctive extrasensory perception. Excavation was conducted by dividing the tunnel into segments of about 50 m long, with a horizontal aeration hole in between. Excavation was done from two directions, downstream and upstream with a working team of three to five persons each. These teams were consisted of professional tunnel workers under the strict technical coordination and guidance of the "witch GANY - INACID 56


Irrigation Tunneling

in Ancient Indonesia

engineer". Ordinary workers, or workers belonged to other group are not allowed to involve in any part of the excavation work. While conducting the excavation from two sides, the witch engineers are continuing exploration by walking along the prospective tunnel alignment and conducting special traditional ritual ceremony which is only known and understood by the witch engineers themselves. Along this exploration, they frequently check the tunnel worker to see if the direction of downstream and upstream axis is matched or deviated. They are detecting the direction of excavation by sensing the sound of crowbars hoe, or other excavation equipments being used to excavate from opposite direction. To detect this sound they usually put their ear at the ground, and from the sound of equipments used from opposite direction, they can determine whether the direction of excavation is correct or it should be corrected. Based on information from the old local farmer, the sensing is said to be easier to detect if the excavation is conducted along the hard rock. The rest of the working and excavation technique and equipments are more or less similar to traditional excavation works implemented in other areas like the tunneling works by Subak organization in Bali and other traditional irrigation areas in Indonesia.

Problems: The problems that they faced during the construction excavation of the tunnel was associated with the difficulties to mobilize resource from the beneficiaries, because they do not have adequate resources on the one hand and the lack of confidence that the tunnel excavation would be successful on the other, as mostly the village community do not have experience nor comparative feature about this kind of works before. This 57 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

problem was resolved by the commitment of two persons (Ama Aja, Ama Saninten, leader and member of the local traditional community) among the community to give advance finance for purchasing material and paying wages on the implementation of the infrastructural works. These pre-financial resources were paid on installment basis by the beneficiaries after the farming has been producing. Other problem was the fore-canal at the length of 200 m downstream of the water intake (weir), upstream of the tunnel because the alignment intervened with a valley of 40 m distance and about 20 m depth. To overcome the problem of conveying the water across the valley, they were constructing a simple aqueduct, using several palm trees set up in parallel to accommodate the discharge required for irrigating the area downstream the tunnel. The construction of aqueduct and irrigation infrastructures below the tunnel undertook by the beneficiaries by means of "gotong-royong" or mutual aid works by the member of water user community without payment. The time of excavation of the remaining irrigation canals were quite long because they have to wait the completion of tunnel excavation in order to start excavating the canal junction immediately at the downstream end of the tunnel. This is because they do not have overall design for both elevation as well as the canal alignment. Accordingly, they have to follow the actual water flow to determine the slope of the canal (this condition is not similar to Bali, where they already have self made leveling equipment â&#x20AC;&#x201C; however simple it was). While the time for excavation of the tunnel itself took almost two years to excavate.

GANY - INACID 58


Irrigation Tunneling

in Ancient Indonesia

Operation and maintenance: Activities of operation and maintenance of the completed irrigation infrastructures was quite difficult to perform by the farmer, because the tunnel, canal and their infrastructures were so simple that they could not immediately utilize without improvement. These were particularly the cases for the difficulty to maintain the simple palm tree aqueduct and the stability of tunnel slope as well as its wetted perimeter. For these purposes, after the long sacrifice of the farmers, the government gave support for improving the weir, aqueduct and tunnel, as well as technical assistance for operation and maintenance of Sindang Gila irrigation infrastructures. The present infrastructural operation maintenance is conducted by the local farmers themselves, but for major repairs, they are still expecting support from the government.

Figure 3.4. The present condition of Sindang Gila Weir, 200 m upstream of the tunnel, after improvement by the government

59 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 3.5. Left, present condition of Sindang Gila Aqueduct after reconstruction by the government; right, upstream entrance of the tunnel, after improvement by the government

Figure 3.6. Left, present condition of the downstream outlet of Sindang Gila Aqueduct after reconstruction by the government; right, typical aeration hole at the distance of about 50 m from each other

At present, the water utilizations served by the Sindang Gila tunnel are not only for irrigated agricultural purposes, but also the water supply almost fulfill the water requirement for the villager and the livelihood of the people in the vicinity area, including drinking water and inland fishery and home industry.

GANY - INACID 60


Irrigation Tunneling

in Ancient Indonesia

Tibu Pungkur Irrigation Tunnel: Tibu Pungkur Irrigation Tunnel is located at the village of Anjani, Sub District Suralaga, East Lombok District, taking its irrigation water from the Kali Bening River. This tunnel has a length of 1,750 m along the steep slope with hard rock and breccia tuff based as well as sandy tuff alignment. The total potential irrigation area served by the tunnel is 250 ha with the functional irrigation area of slightly more than the potential because some area has been extended by initiative of the farmer. Like Sindang Gila Tunnel, the unique feature of Tibu Pungkur Tunnel is that the planning and design were also conducted on the basis of "plan-as-you-go" approach by witch engineer without overall plan by utilizing the power of instinctive extrasensory perception in combination with trial-and-error approach. Excavation was conducted by dividing the tunnel into segments, but the distance is determine by condition of soil and material along the excavation as well as the need for lighting and fresh air for working in the tunnel. The type of aeration whether horizontal or vertical is determined subject to the local condition. Excavation was also conduct from two directions of each segment, from downstream and upstream with a working team of three to five persons each. These teams were consisted of professional tunnel workers under the strict technical coordination and guidance of the "witch engineer". They were originated from other districts within Lombok Island. Therefore workers belonged to other groups are not allowed to involve at any part of the excavation work. Similar with other location, while conducting the excavation from two sides, the witch engineers are continuing exploration by walking along the prospective tunnel alignment and conducting special traditional ritual 61 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

ceremony which is only known and understood by the witch engineers themselves. Along this exploration, they frequently check the tunnel worker to see if the direction of downstream and upstream axis is matched or deviated. They are detecting the direction of excavation by sensing the sound of crowbars hoe, or other excavation equipments being used to excavate from opposite direction. To detect this sound they also put their ears at the ground, and from the sound of equipments used from opposite direction, they can determine whether the direction of excavation is correct or it should be corrected. However, from experience, the old local farmers whom were interviewed explained that for the case of Tibu Pungkur excavation, the workers were frequently hampered by the scattered hard rock that forced them to turn the axis around the boulder, which in turned cause the serpentine axis and often missed the direction from other side of excavation. The rest of the working and excavation technique and equipments are more or less similar to traditional excavation works implemented in other areas like the tunneling works by Subak organization in Bali and other traditional irrigation areas in Indonesia. The excavation of Tibu Pungkur tunnel with the length of 1,750 m took 5 years to complete. Problems: The most significant problem the farmer had during the construction and tunnel excavation was determination of location of weir and direction of tunnels that match with the starting point of the tunnel. Since their approaches were only relying to the witch engineer with extra sensory perception and trial-and-error-approach, the first trial was failure due to the location of weir at the river was set up at the slightly lower place and with unstable soil condition, so the water cannot be discharged to the proposed irrigation area, in addition to the collapsed GANY - INACID 62


Irrigation Tunneling

in Ancient Indonesia

of the weir due to its location at the unstable soil layer. With the badly need for water, despite the undesirable experience, after 30 years dormant, the local community started again to initiate the development of Tibu Pungkur irrigation scheme with its tunnel. Learning from the failure in the past, they move the location of the weir at about 200 m upstream of the past location. And hence, the tunnel alignment was also adjusted with the topography through stable alignment. Other problem they faced during the construction excavation of the tunnel was similar to the Sindang Gila difficulties to mobilize resource from the beneficiaries, because they do not have adequate resources on the one hand and the lack of confidence that the tunnel excavation would be successful on the other, as mostly the village community do not have experience nor comparative feature about this kind of works before. This problem was resolved by the appropriate coordination of three persons (H. Hamdani, Mak Husni and H. Saeran, leader and member of the local traditional community) to manage financial allocation for construction of the canal, tunnel and irrigation infrastructures. They mobilize whatever resources available at the community, and seek private owned source of loan for financing the wages and materials for construction. These financial resources were managed by them in terms of financial arrangement, and later paid on installment basis by the beneficiaries after the farming has been producing. The construction of weirs, and tunnel were carried out by appropriately managed the financial resources, while other irrigation infrastructures below the tunnel undertook by the beneficiaries by means of "gotong-royong" or mutual aid works by the member of water user community without payment. The time of excavation of the remaining irrigation canals downstream 63 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

were quite long because they have to wait the completion of tunnel excavation in order to start excavating the canal junction immediately at the downstream end of the tunnel. Accordingly, they have to follow the actual water flow to determine the slope of the canal (also, this condition is not similar to Bali, where they already have self made leveling equipment â&#x20AC;&#x201C; however simple it was).

Operation and maintenance: Activities of operation and maintenance of the completed irrigation infrastructures was also fairly difficult by the farmer, because the tunnel, canal and their infrastructures were so simple that they could not immediately utilize without improvement. These were particularly the case for the difficulty to maintain the stability of tunnel slope as well as its wetted perimeter along the serpentine tunnel axis. To resolve the problem, after the long sacrifice of the farmers, the government gave support for improving the weir, and tunnel, as well as technical assistance for operation and maintenance of Tibu Pungkur irrigation infrastructures. The present infrastructural operation and maintenance are conducted by the local farmers themselves, but similar to other irrigation areas, for major repairs, they are still expecting support from the government. The organizational aspect of water management in Tibu Pungkur is more advanced because they have already tried the so called Integrated Irrigation Management Approach through water user association, involving local government, stakeholders, NGOs in the water resources and irrigation utilization group (WUA Group). However, they are still expecting routine GANY - INACID 64


Irrigation Tunneling

in Ancient Indonesia

technical guidance, and support of major repairs for irrigation infrastructures.

Figure 3.7. General condition of irrigation area, currently served by Tibu Pungkur Tunnel

65 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 3.8. The present condition of Tibu Pungkur Weir, 200 m above the old weir, improved by the government

Figure 3.9. Left, present condition of upstream inlet of Tibu Pungkur tunnel after improvement by the government; right, typical aeration hole located scattered along 1,750 m tunnel

At present, the water utilizations served by the Tibu Pungkur tunnel are serving not only for paddy, but also for sugar cane, vegetables, and fresh water fishery as well as the other water demands for the villager and the livelihood of the people in the vicinity area, including drinking water and urban settlement around the location.

GANY - INACID 66


Irrigation Tunneling

in Ancient Indonesia

Ledang Bur Tunnel: Thin tunnel was made under the initiative of the farmer at the village of Kali Jaga Selatan, Sub District Aik Mel, Lombok Island, 5 separate locations with the total length of 1,969 meter. The tunnel is made to transfer water from Kali Rumpang to Kali Ledang Bunga for irrigation the total area of 215 ha.

Figure 3.10. General Layout of Ledang Bur Tunnel at the Village of Kali Jaga Selatan, Aik Mel Sub District Lombok for serving 215 ha of irrigation area

The construction and excavation the tunnel was conducted fully by the farmer by using traditional technology. However this works was differed from other tunnel because it was fully conducted by the farmers through the water users association. Every aspect of the tunneling work was planned, discussed and conducted on the basis of mutual aid (gotong royong) approach, and organized by the local leader with an approach of fully democratic principle.

67 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 3.11. The local leaders of Ledang Bur Irrigation Scheme are at the meeting for discussing the way to resolve the problems they are facing

For operating and maintaining the tunnels, the farmers are conducting routine maintenance to clean the tunnel from garbage and sediment deposit. This especially the case for irrigation implementation at the beginning of farming season, or after the flooding season.

Figure 3.12. The inlet of Ledang Bur Tunnel before routine maintenance after the flooding season (left); Routine cleaning of the tunnel (right).

GANY - INACID 68


Irrigation Tunneling

in Ancient Indonesia

Given the fact that the farmers are very difficult to undertake the operation and maintenance of irrigation infrastructures, especially the main intake and the fore canal across the river, the provincial government support the reconstruction of the weir and fore canals that were frequently suffered from damages due to land sliding and flooding. \

Figure 3.13. The fore canal and the main weir Ledang Bur Irrigation Scheme after reconstruction by the government (left); the local traditional community leader at the downstream of the reconstructed weir (right) Other Tunnels in East Lombok District: There are several other tunnels in east Lombok that are currently being put in the local government inventory for proposing operation and maintenance support from the government because the local farmers are lacking of capacity to operate and maintain the ancient tunnel on sustainable basis. These among others are: (1) Tibu Pungkur Tunnel with the length of 2,882 m; (2) Turunan Sampi Tunnel with the length of 225 m; (3) Mencerit Pengabangan Tunnel with the length of 125 m; (4) Montong Teri Tunnel with the length of 3,000 m; (5) Semba Kabujaga Tunnel with the length of 2,423 m; (6) Ledang Bunga tunnel with length of 500 m; and some others at the remote location that area being surveyed for sustainable O&M support.

69 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

CHAPTER IV

RECENT TUNNELING EXPERIENCES IN MAJALENGKA AND TASIKMALAYA DISTRICTS, WEST JAVA PROVINCE 4.1. Cikarag Village, Majalengka, West Java Given the fact that most agricultural practices especially in rural area are highly dependent upon the sustainability of water supply for irrigation. Irrigation development in rural Majalengka District of West Java is not an exception, in which the area which is often suffered from water scarcity, especially during the dry season.

Figure 4.1. Location map of Majalengka and Tasikmalaya Districts of West Java Province

GANY - INACID 70


Irrigation Tunneling

in Ancient Indonesia

Rice crop, which is the staple food for most people in the country, needs high and steady supply of water for its optimum growth. The farming activities in Cikarag, Bantarujeg, Kabupaten Majalengka is not the exception in this matter. Kampung Cikarag is remotely located behind Mount Lamping. This village, one of the rural areas in Majalengka District, lies about 12 km from the district capital called Banturajeg. The connection between the two places is only minimum and only useful for small vehicles in dry seasons. Most of its people earn their living from growing seasonal crops with some perennials in their generally-small strips of gardens as the means of obtaining additional income. The hilly nature of Cikaragâ&#x20AC;&#x2122;s topography forces the local farmers to use their best efforts in cultivating the crops, either in rice field or in the narrow strips of garden. At present, most of the existing rice fields are supplied by the village irrigation systems having the irrigating capacity ranging from 5 to 15 ha. Because of the steep and hilly topography, irrigation systems have to follow the contour of the ground to allow continuous flow of water from plot to plot (plot-to-plot scheme). Facing such constraint to deal with nature, the farmers instinctively cultivate their rice fields in intensive way, especially with the aid of technology frequently introduced to them on these days. With the guidance in the irrigation technology and farming practices from the Government, the farmers in Cikarag have acquired the knowledge of proper use of fertilizers, good cropping techniques with progressive farming technology, using prime seeds (high yielding 71 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

variety â&#x20AC;&#x201C; HYV), application of the technology to control pest/diseases, processing and storage of harvested crops, and supplying proper amount of water from the existing irrigation system to their farmlands.

Figure 4.2. Typical terrace paddy field system in Cikarag Village The farmers take the water for irrigation from the nearby rivers/steams and channel it through simple networks they have built together using whatever technology and resources available to them in the process, just to provide enough water for their own group of community. With the hilly topography, however, the farmers are often compelled to make crossing structures such as gutter and aqueduct across the hills or even dig the tunnel through the hills in order to bring irrigation water to their farmlands.

GANY - INACID 72


Irrigation Tunneling

in Ancient Indonesia

4.2. Kampung (village) Neglasari, Panca Tengah, Tasikmalaya District Community Profile: Kampung (village) Neglasari, Panca Tengah, Tasikmalaya Neglasari is a remote village in the southern slope of active volcano, Mount Galunggung, about 74 km from the capital town of Tasikmalaya District. Administratively, this village belongs to the newly reformed sub district of Panca Tengah (formerly expanded from sub district of Cikatomas). During the dry season, Neglasari village is easily accessible by two wheel vehicle, and four wheels vehicle as well, but the road has not been paved by asphalt pavement and mostly are under the severely damaged condition. The motor cycle from Tasikmalaya to Neglasari will take about three hours, while by four wheeled car will take about four hours or more, through a rocky, undulating, and narrow road. Such transportation condition isolates Neglasari from the noisy city live. During rainy season, this connection is almost impossible to reach by four wheeled vehicle. Most of the people in Neglasari earn their living from farming (rice) and growing palawija (sweet potatoes and cassava, as well as corn and ground nut). The hilly nature of Neglasariâ&#x20AC;&#x2122;s topography and with water scarcity compels the local farmers to work harder for their livelihood. The lack of adequate water supply for farming allows the farmersâ&#x20AC;&#x2122; cultivation on dry field only. In 1982, the disastrous eruptions incidence of Mount Galunggung, which hampered the other villages quite significantly, burying the farm land, houses, animals, and materials possessions of the people under the deep ashes deposit which thrown up in the eruption, did not affect the Neglasari Village, which was started to enjoy the Abdul 73 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Rojak Irrigation scheme. Therefore, not many people left their destroyed village for saver places like other villages. Abdul Rojakâ&#x20AC;&#x2122;s family was not affected by the volcanic disaster they did not leave their own village like other people did. In fact the operation and maintenance of the newly developed irrigation scheme was started to be implemented after 6 years efforts to work hard developing the canal and infrastructures which was initially considered impossible by the villager. In fact, in 1974, under the silence of the village that has been terribly suffered from severely lacked of water for irrigating the upland and undulating area, a bright idea was born from a villager, Abdul Rojak, who previously making a living as agricultural labor, helping people tending crops, planting and hoeing for a meager return. His bright idea was to develop an irrigation scheme consisted of small weir from Ciharuman River, with 2 km fore-canals along the foot of the steep valley, across a hill of massive rock, even the tunnel was only about two hundred meters long, but no one at that time considered the plan as logically possible.

Figure 4.3. Typical terrain of Neglasari Village without irrigation

GANY - INACID 74


Irrigation Tunneling

in Ancient Indonesia

4.3. SOCIAL-ECONOMIC PROBLEMS AND THE STRIFE FOR PROVIDING ADEQUATE RICE AS STAPLE FOOD The farming communities (in rural areas) generally live marginally at subsistent level so that they have to earn additional income from other sources in order to meet their day-to-day needs, particularly to support the children education. Hence, the social economic condition of the rural community is highly dependent upon the source of income accessible to them. Most of the villagers have to eke out their living from other sources of income besides farming. Like other people in Majalengka and Tasikmalaya Regions, the people of Neglasari are mostly earn their living from farming or working as farm laborer in both wet rice fields and dry farmlands. Only very few of the farmlands in Neglasari at that time were irrigated; the majority of the land consisted of rice fields and dry farmlands (rain-fed). In order to secure enough supply of rice as the staple food of the people, with the support of the existing irrigation systems, the local farmers have no choice but additionally planting upland rice on their land without irrigation, accepting the risks of low production and failure in harvesting. There are also some farmers that grow perennials and fruits (such as cloves and rambutan, -- nephelium, bearing fruit similar to lychee fruit -respectively), but their dependency on rice as staple food force them to use part of their land for growing rice. General observations have shown that the farmers who grow rice as well as perennials, such as cloves, have relatively better living conditions than those growing a single crop of rice. When the market price of cloves is rising, the multi-crop farmers will collect enough money 75 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

to meet their day-to-day needs; some of them can even afford to pursue the pilgrimage to Mecca for fulfilling one of the Moslemâ&#x20AC;&#x2122;s basic obligations, which becomes the ultimate obsession for most of the believers. Other farmers, mostly men, who do not grow perennials in their lands, have to leave their native village to the nearest towns and cities in search of additional income, working as skilled or unskilled labors, earning whatever off-farm income within their capacity. 4.4. A BREAKTHROUGH OF A VILLAGE-WOMAN (IBU YUYU YUSANAH) IN PARTICIPATORY IRRIGATION Ibu (Mrs.) Yuyu Yusanah, a women-village figure lived in a remote village behind Mount Lamping, namely in Desa (Village) Cipeundeuy in Bantarujeg District, Kabupaten Majalengka in West Java Province. She conceived a bright idea for her village and had willpower of steel rarely attached to people, especially woman, of her age. This village figure took initiative in the development of the irrigation network that would supply water to the rice fields. Until that time, the rice fields of Cikarag had always been depending on rain for its supply of water (rain-fed). The great initiative of this woman that was born from simple way of thinking had convinced the village community to participate in the simple irrigation development activities. With full of self-confidence, this lady organized the locals, mostly men, to work together in the construction of the irrigation infrastructure. The effort finally paid off when the water began to flow from its source Kali Ciawi through the network into the rice fields. Although the irrigation system itself was very simple with GANY - INACID 76


Irrigation Tunneling

in Ancient Indonesia

a weir made of stone piles riprap (rock fill) and a primary canal across the hill, the most amazing things was the initiative of Ibu Yuyu and the performance of the people involved in excavating a tunnel of 154 m through a hill at the average depth of more than 10 meters from the ground surface. Through this tunnel the water flown into the rice fields downstream.

Figure 4.4. Yuyu Yusanah in her house

Figure 4.5. Rural community profile of Cikarag Village, Kabupaten Majalengka 77 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

The work was begun in early 1987. Considering the steepness of the work location, it was almost impossible for the locals to cut a canal along the hill with the existing resources and technology. Pushed and motivated by the urgent need for irrigation, Ibu Yuyu Yusanah, equipped only with strong willpower and faith, decided to excavate the tunnel through the hill all by her. She resolved that she would dig the tunnel alone if nobody in the village offered any help or assistance. With deep faith and guided only by her feeling, she started to dig the tunnel, all alone, using simple tools consisted of a hoe, a pickaxe, and a piece of mirror taken off from her closet that she used to reflect the sunlight into the canal while she was digging. At that time the people of her village considered her efforts wasteful and hardly acceptable in common sense; many of them mocked at her persistent attempts and accused her of hallucinating. Such treatments only strengthen her effort to proof the success of her plan to the people. After working alone for some time, some of the community began to have faith in her work and others, although hesitantly, were eventually convinced to share the enormous work load. In spite of the support, the progress of the work was halting. The people were lacking in technology and equipment, not to mention funds. Ibu Yuyu remained faithful to her commitment although she had to sell most of her possession to buy food and tools because she hardly had any income working on the irrigation. Such a deprived condition did not lessen the spirit of this brave woman that had spent so much on the development of the irrigation (according to the information given during the interview with Ibu Yuyu, the GANY - INACID 78


Irrigation Tunneling

in Ancient Indonesia

total cost that had been directly paid by herself to complete the work was about the cost going to Mecca, or equal to US$ 2,700 in January 2002 when the initial publication was still under preparation). She had met considerable challenges and obstacles and, only after two years of hard work breaking through the hill in order to bring the flow of Kali Ciawi into the rice fields, her dream finally came true.

Community profile Kampung Cikarag and the role of Women in rural development Source of Income: Most of the people of Cikarag make their living from farming. Dry fields and rain-fed rice fields take about 75% of the total farmland of the villages, while the remaining 25% is the land served by the village irrigation that have been developed independently by the farmers. Kampung Cikarag is occupied by 17 families totaling 102 persons (48 men and 54 women), 51 of which are adults.

Role of women: In day-to-day activities, the women of Cikarag hold significant role, particularly in farming. The women share all the farming work from preparing the land for planting (land preparation), planting, tending the crops to the handling of post harvest production. At home, the women still had to do the cooking and prepare the food for family. They are also involved in social and religious activities such as arisan (raffle by neighborhood women), PKK (home economic activity organized in each village) and reading the Holy Koran in the village mosque. Growing rice in the rice fields dominates other activities but do not bring enough money. Therefore, besides working side by side with the women in the rice fields, the men have to leave their homes in search of 79 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

additional income working as peddlers or labors. From the 48 men in the village, 7 of them (head of families) become the head of the family with full responsibility in raising the children. With all that works, they still manage to do the farming work appropriate to the season. A. The Strive for Development Development and management of village irrigation and transportation infra-structures: As previously described, Cikarag is a remote and isolated village behind Mount Lamping. Being remote and having hilly topography, Cikarag has not shared the benefit of the development programs launched by the central or regional government. The absence of development programs in this area is obvious as shown, among others, by the condition of the muddy road that connects Cikarang and Bantarujeg. This unpaved road makes travelling difficult, particularly in rainy seasons when it is not even good for two-wheeled vehicles. In such condition, the economic activities of the village were practically stop. Development of adequate transportation and irrigation infrastructures to build the village economy and increase the farming productivities were highly desirable to Cikaragâ&#x20AC;&#x2122;s community, but these people did not have capacity to build them independently. They need the Government support in this case, without which Cikarag would hardly improve. Facing such a prolonged uncertain condition, a courageous woman came forth and took the initiative in the development of the covetous irrigation, the irrigation GANY - INACID 80


Irrigation Tunneling

in Ancient Indonesia

they have been expecting from the Government but have not realized so far. In 1984 Ibu Yuyu Yusanah rose from her contemplation to make her peopleâ&#x20AC;&#x2122;s dream come true. She initiated the development of the irrigation network that would bring better life to her village. Her idea was to put weir across Kali (River) Ciawi and divert the water discharge into a primary canal that run through a tunnel she was going to dig through the hill in order to reach the village rain-fed rice fields. Such an idea had never been conceived by any one before. The irrigation development led by Ibu Yuyu Yusanah changed the unproductive rain-fed rice fields and dry fields of 12 ha into adequately irrigated farmland that assures at least two rice crop planting a yeas with the possibility for growing palawija in between. From a macro development perspective, the scale of work and contribution given by Ibu Yuyu and her people to the economic growth of Cikarag is not too significant. However, behind the initiative of this women, there is an important moral value and a lesson to learn by all: Things that seem impossible at first sight can be attained when one has enough self confidence, consistency, faith, strong willpower, and willingness to give example in changing vision into reality and reaching successful end. The successful development of irrigation networks by a village women figure makes significant evidence that defies the general view, especially in developing countries, that considers women the weaker gender and is always under the oppression of male supremacy. Such a view is no longer applicable in the present age of progress. Even in former times, development activities in Indonesia always involved all members of the community,

81 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

including women, as appropriate to their in-born characteristics and role.

Figure 4.6. Yuyu Yusanahâ&#x20AC;&#x2122;s paddy field

B.

Development of Irrigation Infrastructures

Design, construction and management of the completed structure: With strong willpower, commitment and consistency, Ibu Yuyu started to put her idea of developing the village irrigation into reality. First, she made a simple design of the system, constructing most of it on her mind instead of on paper such as commonly practiced in the modern world. In 1984, she began the work. Fist, she was helped by her family and, after some time, by the village people. GANY - INACID 82


Irrigation Tunneling

in Ancient Indonesia

The fist work to do was taking measurements. She used a length of bamboo rope tied to some bamboo stakes in order to define the course, position, and length of the canal alignment she was going to make. Thinking that the water in the tunnel would flow to a lower place, she began the excavation from the downstream side (rice field side). The bottom level of the canal was positioned in such a way to allow direct irrigation of the rice fields around the tunnel mouth. By guess work, the tunnel excavated from the downstream was projected to be on the same level with the bottom of the canal that would stretch along the bank of Ciawi River to the upstream mouth of the tunnel. The original idea was to dig an open canal of 200 m around the steep slope of the embankment. If this idea had been adopted, however, the canal alignment that started from the weir location would have been on a steep bank. Such condition makes the works extremely hard to do because the canal has to be cut right on the steep slope of the embankment. Even if the works is practicable, the maintenance of a canal on steep embankment will be difficult, especially the repair work that has to be done after each land slide. With this consideration in mind and led by the instinct, it was decided to dig a tunnel instead of implementing the original idea. At first, the tunnel excavation was done from one direction only, namely from down-stream, for practical reasons. Later it was continued from both sides simultaneously (downstream and upstream). During the excavation, flashlights and sunlight reflected from a piece of mirror provided lights for the people working underground. At the upstream end, lighting came only from flashlights because the location was shaded by trees impenetrable by sunlight. However, soon the flashlight had to be abandoned because of expensive batteries that need frequent replacement with new ones and inadequate 83 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

lighting capacity. At the downstream end, a piece of mirror taken off from a closet reflected the sunlight into the tunnel. Such was possible since there were no trees screening the sunlight from the work location. Using pickaxes, crowbars, hoes and garbage spade to remove the excavated soil, the first work began with the help of 4-5 people. After a month, the working crew had to be reduced to 2-3 people only due to uncertain financial condition. The work interval depended on the availability of funds, particularly to buy lunch and refreshments for the working men. For this reason, the work repeatedly went in a stop-and-resume cycle. The tunnel with the length of 154 m having a ceiling in the shape of a halfsegment, a width of 0.80 m and a height of 1.45 m took about two years to complete. After the completion of the excavation work and the flow of the water downstream through the tunnel had been proven, the next work to do was making the conveyance canals. It started with the measurement of the canal alignment along the embankment slope up to the weir location, and followed by the cutting of the canal, in which the bottom slope was contrived to be at the same level with the ground by the canal alignment. A simple weir of rock-fill type with reinforcement of bamboo stakes and a crest of 1.00 m from the river bed was made to cut the flow of Kali Ciawi. With the completion of the weir and the conveyance canal, the water from Ciawi River can be tapped using a free intake made of stone that had been cut to resemble a water gate structure.

GANY - INACID 84


Irrigation Tunneling

in Ancient Indonesia

Figure 4.7. Situation Map of Irrigation infrastructures in Cikarag Village, Majalengka District, West Java Province

85 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 4.8. The Cross-Section of the tunnel developed by Ibu Yuyu Yusanah

GANY - INACID 86


Irrigation Tunneling

in Ancient Indonesia

Figure 4.9. Simple Rock-fill weir

Figure 4.10. Improvement of the Simple Rock-fill weir

87 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 4.11. Downstream view of the original tunnel

Figure 4.12. Sketch of upstream view of the original tunnel

GANY - INACID 88


Irrigation Tunneling

in Ancient Indonesia

C. Preparatory Works and Community Organizing Before putting her idea into application, Ibu Yuyu Yusanah made serious preparation including collecting the simple tools for measurement and excavation, provisions at the materials, and money from her personal savings. With strong commitment and spirit, she did not hesitate to call her neighbors and convince them that her idea was worth a try. When the people had been convinced, she persuaded them to help developing the network. At first, the idea of Ibu Yuyu Yusanah was considered controversial by most. It was quite beyond the common sense that it would work at all, but she did not give up easily and kept motivating the people until they were eventually convinced and willing to help in return for a small daily wage or simple lunch and refreshments. D. Problem encountered and solutions Main Problems: Many problems encountered during the development of the irrigation networks (particularly when working on the rock-fill weir, primary canal, conveyance canal and the tunnel). The most difficult one was the limited technology, experience and skill owned by the human resources doing the work. Additionally, there was also severe financial problem and uncertain economic condition of the village. Problems in construction: The heaviest work in the development of the network was the excavating the tunnel. Firstly, the people had neither appropriate knowledge nor experience to do the work. There was also the fear of failure or cave-in that could occur anytime inside the tunnel. The work would certainly take most of their time, mind, and energy besides causing worries and hesitations especially with regard to the money that had to 89 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

be made available to buy tools for the excavation that seemed so much for someone of Ibu Yuyuâ&#x20AC;&#x2122;s condition. The tunnel of 154 m was finally completed after two long years of hard work. The total cost spent on the tunnel at that time was estimated to equal the cost for going on a Holy Pilgrimage to Mecca or about Rp. 27,000,000 (US$ 2,700.00 on January 2002 exchange rate). To Ibu Yuyuâ&#x20AC;&#x2122;s family of subsistent farmers, such amount was enormous. With faith, consistency and prayer, the network was finally completed and has been functioning satisfactorily since 1987. Operation and Maintenance Problems: like the technical-irrigation network, the village irrigation developed by Ibu Yuyu and her neighbors began to lose some of its function after some time, especially those associated with poor workmanship and simple technology, as well as the random materials used in the construction (tunnel excabation). One of the difficult problems faced by the villages is high rate of sedimentation along the canals and the tunnel due to inadequate sediment trapping facility. The sedimentation causes shoaling of the canals and tunnel bed. This problem is made worse by the falls and slides of the soil within the tunnel that have not been provided with necessary reinforcing structures (such as the ones made of wood, iron, masonry work, or concrete) in the first place. Other difficult maintenance work that has to be done routinely each planting season is cleaning the tunnel, for which, people have to enter the tunnel, remove the accumulated sediment and garbage before hauling them outside to allow easy flow of water through the tunnel into the farmlands to more freely. The problem is usually associated with the narrow space, inadequate lighting and GANY - INACID 90


Irrigation Tunneling

in Ancient Indonesia

the risk of slides of falls of tunnel materials that could occur any time. Although dredging has been made along the tunnel, the supply of the irrigation water into the rice fields is still hampered by the fall of soil materials that keep happening inside the tunnel. 4.5. SUCCESSFUL APPLICATION OF ANCIENT TRADITIONAL TUNNELING TECHNIQUE BY AN ENTHUSIASTIC WOMAN A. Indigenous Technology Technical design: the design of the irrigation network developed by Ibu Yuyu was merely based on simple and logical considerations, and not documented on paper or technical drawings. The construction of the rock-fill weir, primary and secondary canals and the tunnels were done purely by instinct, strong willpower and consistency, as well as hardly supported by knowledge, technology or experience. She used only local materials found at random and simple tools to do the big work for the villagers. Determining the alignments of the primary canal and the tunnel: The first step conducted by Ibu Yuyu in determining the primary canal alignment was to set up the location of the upstream, and the downstream tunnel. The level of the canal bed at the upstream end of the tunnel was determining to be at the same level with the highest point in the canal alignment, which was obtained by comparing the levels of the boundary between the slope and the gully, following the water course from the â&#x20AC;&#x153;free intakeâ&#x20AC;?. Whereas the downstream (outlet mouth) of the tunnel was positioned at the same level with the highest rice field elevation. In this way, the flow of water from the 91 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

primary canal into the highest elevated rice field will be assured. The technical constraint that still prevails in the operation and maintenance of the canal is that the bed can become too steep; the slope inclinations, in the end, is whatever formed by the excavation since no theoretical calculations of the maximum allowable slope inclination had been made. Determining of the crest level: The crest elevation of the weir determined in such a way whether or not the water can be trapped for discharging into the primary canal and their subsequent networks. Determination of the crest elevation was done by trial-and-error, starting by drawing a line of bamboo rope from the upstream mouth of the tunnel at a slope that allow flow of water from the free intake gate. The crest level was determined based on the height of the stake placed on the intake point plus freeboard so that the flow of water from the primary canal to the tunnel mouth would be maintained even at the lowest water level. Construction of the rock-fill weir: The weir is made of stone piles/rock-fill reinforced by bamboo stakes and framework to protect the rocks from being washed away by floods. To prevent leakage, hay and other organic wastes have been stuffed between the rocks. The stuffing is expected to reduce the seepage through the weir body so that most of the water would flow into the intake, even though the river is at the lowest water level. The crest elevation was determined at about 1.0 m and the width was 0.40 m. such dimensions are considered adequate and safe for medium floods. However, damages will still occur in large floods, GANY - INACID 92


Irrigation Tunneling

in Ancient Indonesia

although not to the entire body of the weir. Immediately after a large flood, the weir can be repaired to its former condition without too much trouble. Intake structure: An intake structure has been made to facilitate the withdrawal of water from the canals into the rice fields. The intake from the weir to the primary canal was made of a massive rock that was cut to a width of 25 cm and height 25 cm. It was placed on the left side of the crest with a soil-covered rock slab on the top to prevent excessive discharge of thrash, sediment and water into the canal in large floods, so that after-flood cleaning/ maintenance work will not be too hard.

Conveyance Canal/Tertiary Canal: The Conveyance canal/tertiary canal is a dug earth canal aligned along the slope of the embankment. The width of the canal bed ranges between 0.24 and 0.58 m, and the water level between 0.06 â&#x20AC;&#x201C; 0.13 m. the length of the primary canal before the tunnel mouth is about 208 m. with this configuration, the average discharge from the primary canal into the lower (downstream) mouth of the tunnel is about 15-20 liters/second, which is enough to irrigate 15 ha of rice fields. The tertiary canals with access into saluran cacing (farm ditch) are open earth canals, directly dug following the ground level of the rice fields so that all of them will have enough water for growing rice. Gutter: The primary canal is provided with drainage to discharge the rain water which is located about 75 m from the pintu sadap utama (the main intake gate).

93 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 4.13. Free intake was made of a massive rock

Figure 4.14. A simple gutter made of a split trunk of palm sugar tree

GANY - INACID 94


Irrigation Tunneling

in Ancient Indonesia

To bridge the curving drain, a simple gutter has been made of a split trunk of palm sugar tree. The cross section of the gutter is enough to safely discharge the full capacity of the primary canal. This sugar palm gutter is quite effective because it material is easily found around the village and durable too. It can stand for five years of use without wearing. Settling pond: In rainy season, the river carries heavy load of sediment. In order to reduce deposition inside the tunnel, the water is passed through a setting pond/tank (width: 2.50 m, length: 10 m) before entering the upstream mouth of the tunnel. Technical configurations of the irrigation tunnel: As previously described, neither technical drawings nor specifications such as commonly found in engineering practices had been made in the planning and construction of the tunnel. Accordingly, the authors tried to take the measurements necessary to identify its technical configurations and to prepare comprehensible technical drawings. The configurations resulted from the measurements are as follows: width 0.80 m, average height 1.45 m and length 154 m, and the tunnel has been cut through ordinary soil and hard soil/rocks without any reinforcement. The average depth of the tunnel bed from the ground surface is more than 10 meters, with inletoutlet difference of about 6.774 m so that the average slope of the tunnel bed (s) is about 0.0441. According to the general criteria of tunnel planning, such slope is categorized as very steep with high potential for bed scouring at high flow velocities, but at normal flows the slop effectively discharges water from the tunnel into rice

95 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

fields (see the measurement drawing of tunnel slope on Figure 4.8.). Mobilization of resources (Money, Man, Material, Equipment, Logistic): For the successful development of the irrigation networks, all resources had been exploited to the maximum, in accordance with the local condition, capacity, and availability. The provision of funds in this case was only limited because there was not any definite source of income to secure in the uncertain condition of the village economy. The principal income came from the sale of palawija, which was not much because of low productivity in the absence of farming facilities such as adequate irrigation. Such financial condition gave significant impact on the implementation of the work. The meager supply of money had to cover the purchase of tools, food and other logistical supplies so that stringent prioritizing was always needed. The total cost for developing the network, as previously mentioned, was about equal to US$ 2,700 (on January 2002 rate), spread over a period more than two years from 1984 to 1987. As to human resources, the local community, after much convincing, readily helped the tunnel excavation and the development of other irrigation components as long as weather permitted and supply of tools, food and other necessities had been assured.

GANY - INACID 96


Irrigation Tunneling

in Ancient Indonesia

Figure 4.15. A semi water tight gabion weir was given by the research institute for water resources, as a technical assistance.

Figure 4.16. Rock fill structure on the upstream tunnel inlet was also given by the research institute of water resources as a technical assistance. 97 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

4.6. SUCCESSFUL APPLICATION OF ANXIENT TUNNELING TECHNIQUE BY A VILLAGER ( A B D U L R O J A K ) I N TA S I K M A L AYA DISTRICT A. Irrigation Development, Simple Planning, construction and implementation The urgent demand for Irrigation Development and Management: Neglasari village due to its remote location in the southeastern slope of active volcano, Mount Galunggung, about 74 km from the capital town of Tasikmalaya District, on top of its undulating and hilly topography, the village has not been touched by significant development program either by the regional or by the central government program. Being the case Abdul Rojak was motivated to develop irrigation, despite the difficulty of terrain and unavailability of capital, lacking of techniques and practical experience. Indigenous technology: The design of the irrigation network developed by Pak Rojak was merely based on simple and logical considerations, and not documented on paper or technical drawings. The construction of the rockfill (rip-rap) weir, primary and secondary canals and the tunnels were done purely by instinct, strong willpower and consistency, hardly supported by knowledge, technology or experience. He used only local materials found at random and simple tools to do the major work. So far, nobody knows how was the idea, knowledge and concept was, the people of his group only knew that the idea was launched by Abdul Rojak based on the difficulty to earn a living in his village, because most of agricultural land are merely rain-fed with the total potential area for irrigation at about 120 ha. At the initial stage, Abdul Rojak was conceptualizing the idea without external or internal support. Many of the community members are GANY - INACID 98


Irrigation Tunneling

in Ancient Indonesia

considering him as irrational, crazy, even some considered him as idiot people. With the absence of support and participation of the people, he asked the help of 20 persons (workers) from the village of Kawali in the neighboring District of Ciamis. He employed 7 persons to work for the weir construction, and 7 persons at the excavation of fore-canal as well as 6 persons for the tunnel excavation at the wage of about Rp400/day (at 8 hours works per day). The construction was started in 1975, and completed in 1981. The tunnel alone took one year to excavate by 6 persons, using about 2.5 tons of steel tools, hammer, chisel etc.

Figure 4.17. The main weir before redesign by the Local Government (1); Rice cultivation along the left bank of the fore canal (2); Profile of the villagers in Neglasari (3); rice cultivation on Irrigation Scheme (4)

99 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

B. Irrigation Weir and Fore Canal Main Irrigation Weir: The simple weir made of riprap gabion was constructed in 1975 at the Ciharuman River with the width of 30 meters. In order to keep the stone and boulder at the stable position, nine years later 1n 1984 he used mortar (combination of lime and brick), and he set up the intake gate to the main canal in the form of temporary stop-log just for controlling the water. After the work has been successfully completed, the local government assisted the improvement of the work by redesigning the weir and setting a permanent weir at about 15 meters downstream of the original location with the width of about 40 meters across the river. This action was considered to give appropriate sit for weir foundation. The crest of old weir inundated at about 30 cm below the water level, but the structure is still under the firm condition till present. The fore canal was also improved, especially for stabilizing the canal along the steep slope at the foot of the rock bank. The initial design was made in such a way that the fore canal alignment will be parallel with the foot of the valley along the steeply sloping river bank. The length of the canal is about 2 km from the weir intake till the mouth of the tunnel downstream. The total irrigation area was estimated by Abdul Rojak at about 120 ha. However, this figure was merely through rough estimation, without cadastral measurement. At present, there are about 20 ha of the area is currently managed by irrigation schemes under the local Government of Ciamis District.

GANY - INACID 100


Irrigation Tunneling

in Ancient Indonesia

Axis of old weir, the crest is about 30 cm below the water level

Figure 4.18. The location of old weir at about 15 meters upstream of the new weir (submerged at about 30 cm below the water level), the condition is still stable

It is therefore estimated that there are about 30 ha of irrigation area that are currently irrigated under the Rojak Irrigation Scheme, and expected to extend to 50 ha more at the downstream of the present irrigated area. There was actually some technical support from the government, for construction of the appurtenance and infrastructures downstream, but only lasting for one year, then the canal become collapsed because the terrain was so undulating and the construction cannot stay stable due to the lacking of Operation and maintenance, and this was also because the farmer had not possessed adequate fund for performing land reclamation with appropriate operation and maintenance follow ups.

101 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

There are several side spillways along the for canals with the width of about 0.8 m, which are actually provided for controlling the water depth at the fore canal, as well as spilling the excess water during the high discharge, usually during fool at the rainy season. For irrigating the areas across the Ciharuman River, which in fact located at the neighboring District of Ciamis, are extending plastic pipe and take the water directly from the fore canal, with the permission of Abdul Rojak as the owner of the irrigation infrastructures. In addition to irrigation purpose, the people in the vicinity areas are utilizing water for drinking water, fresh water fishpond, for cattle and for supporting other livelihood purposes.

Figure 4.19. The weir after redesign and reconstructed by the local government (1); Side spill way at the fore canal (2); the reconstructed canal bank (3); the canal parallel with the steep river bank (4)

GANY - INACID 102


Irrigation Tunneling

in Ancient Indonesia

The fore-canal of 2 km was constructed through the steep river bank on the massive rock, some others through the breccia tuff, and hard soil.

Figure 4.20. General lay out (non-scale map) of the Abdul Rojak Irrigation Scheme 103 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

The width of the canal at the rock bank is set up at 60 cm, and the water height at 70 cm, while the canal at the hard rock is set up at the width of 1.20 m with the water height at 0.5 m. Thus the water velocity is estimated between 0.8 m/second at the rock bank, and 0.6 m/second at the hard soil bank. Given this figure, it is therefore estimated that the canal discharge entering the tunnel is about 300 Liter/ second. Thus the water availability at Ciharuman River is quite stable, and the discharge diverted through the main canal is more than adequate to irrigate 120 ha, and to meet the water demand for live of the people in the vicinity area.

Figure 4.21. Typical paddy field at the lowland valley of the Abdul Rojak Irrigation Scheme

C. General Feature of the Fore-Canal Despite that the layout of the 2.00 km fore-canal is entirely set up at the open channel excavation, but it is mostly located at the foot of the steep sloop of the rock, GANY - INACID 104


Irrigation Tunneling

in Ancient Indonesia

which are almost 90 degrees vertical. In fact, the construction or rock excavation under this condition is more difficult than the rock tunnel. The workers have to make bamboo stagger or simple scaffolding hung along the rock wall while cutting the rock to meet the required cross-section of the canal. See the sketch and the photograph below for further illustration.

Figure 4.22. The average profile of fore canal at the rock

105 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 4.23. The general condition of fore canal which was excavated along the steep rock bank of the hill along the river

D. General Feature of the Tunnel At the end approach of the fore canal, the tunnel was excavated through the heel at the completely massive rock with the size of 1.00 m width and the height at 2.00 m. The length of the tunnel with strong ceiling is 132 meters. From the point of view of the length of the tunnel, the Rojak Tunnel is not so significant, but from the traditional tunneling technique, it is very unique because the excavation was conducted through the massive rock by traditional manual labor. E. Determination of the Size and Bottom Slope In comparison with the ancient tunneling practice in Bali and Lombok island the Rojak Tunnel is very simple and without sophisticated technical consideration. Everything is merely based on trial and error estimation. The bottom width was determined only for giving space to work for excavation inside of the tunnel. So did the height of the tunnel was determined to allow adult GANY - INACID 106


Irrigation Tunneling

in Ancient Indonesia

people stand freely without being constrained by the ceiling of the tunnel. So the cross-section of the tunnel was not designed for allowing the water discharge to flow proportional to the total area to be irrigated. In fact, the size of the tunnel and the discharge of the water are somewhat over estimated.

Figure 4.24. The middle-part of the tunnel (1); The entrance of the tunnel (2); The downstream of the tunnel (3); and Transition of downstream and upstream which was not match with the tunnel axis during construction (4)

Based on the authorâ&#x20AC;&#x2122;s rough estimate, the actual discharge of the canal entering the tunnel is currently at least 300 Liter per second, which is based on practiced would be more than enough to irrigated the land for lowland rice at about 200 ha, by continuous flow system. While the total land within the village to be irrigated from the Rojak Scheme is only about 120 ha. See Figure 4.20. 107 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Below, the photographs of the tunnel, which is somewhat over sizing, for the total area of only 120 ha.

Figure 4.25. The photographs of the tunnel, illustrating the size of the excavation which is somewhat over sized

Concerning the slope of the tunnel bottom, it was also determined by estimate of about 30 cm different between the upstream entrance and the downstream outlet of the tunnel, so if the length of the tunnel is 132 meter (based on the first information from the villager, the total length of the tunnel was 300 meters, but as we asked them to check with our presence, it is only 132 meters) the bottom slope is about 0.002273 which is more or less reasonable for the canal configuration of such size. The difference of height in term of (MSL) between the upstream and the downstream of the tunnel was measured by drawing a straight line following the axis of the proposed tunnel across the rock hill. The height is measures by stages from one stake to another with the distance of about 2 meters, by using transparent hose at the length of 20 meters, filled with water. By summing up the height between one stakes to another till the peak of the heel from the direction of downstream, then balance it GANY - INACID 108


Irrigation Tunneling

in Ancient Indonesia

with the cumulative height at the upstream, from this difference they obtain the horizontal level between upstream and downstream. Before starting the excavation, they double-checked the result of the leveling by using plumberâ&#x20AC;&#x2122;s leveling equipment and string for determination of the height difference. The slope then is determined by lowing 30 cm of the level at the downstream benchmark. The different depth of the bottom and the top of the top of the hill is about 30 meters. See Figure 4.26., the sketch illustrating of the traditional measurement of the slope of the tunnel base. The only problem they faced during the tunnel excavation was that the axis of the tunnel from upstream and downstream was not match. It was about 50 cm dispersed from the axis in the middle, which was merely by the fault of the worker.

Figure 4.26. Traditional measurement for determining of the slope of the tunnel base

109 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

The distance between upstream and downstream point had been quite differed significantly between the actual horizontal distances because the straight line was measured by drawing plastic tape which was in fact stretched beyond the actual measurement. The problem became apparent when they tried to draw straight axis, which in fact not matched, then it did not meet at straight line. To resolve the problem of missing the target at about 0.5 meter from the original axis in the middle (the excavation was done from two directions) then both directions were adjusted to make slight transition turning lightly to meet each other.

F. Construction Implementation The feature of irrigation infrastructure including tunnel is not as significant in terms of its contribution to economy as a whole, however the construction become more attractive in terms of its initiative from the common villager without technical knowledge, experience and financial capital. The works are merely conducted in terms of traditional technique by using the local resources, and yet without support from local people. The construction was started in 1975 for over 6 years (weir was constructed for 2-3 years, including weir and fore canal, 2 years for irrigation networks at the downstream involving 20 persons. While the excavation of the tunnel was conducted for one year involving 6 persons from two directions simultaneously each direction of the tunnel consisted of 3 persons (working night and day). It was estimated that during the construction it consumes a total of one ton steel crowbar and chisel for excavating the massive rock. GANY - INACID 110


Irrigation Tunneling

in Ancient Indonesia

For the construction of this scheme, Abdul Rojak as the initiator of the work without support from the farming community was suffered from budget capital for paying the worker as well as providing for equipment and material. He was in fact sold seven blocks of his agricultural land for financing the construction of the scheme. It was about 10 ha altogether with an estimate of about Rp.12,500,000 (converted to about Rp.625/ US $1.00,- or in total at about US$ 20,000), which was a great deal for the villager’s farmer like him at that time (1980’s). G. Operation of the Tunnel and Irrigation Scheme Operation of the irrigation system was started in 1981, under the direct command of Abdul Rojak as the initiator of the development construction and the owner of part of the land irrigated by the system. During the initial operation, the members of farming community in that area were not involved in the operation; however, they were requesting to utilize irrigation water for their land. As the matter of fact, the persons who were initially against the idea of irrigation development in fact are insisting later on the use of water for all the related irrigation system in the village. This mater was later on become problem, concerning the capital sharing, role sharing, and risk sharing of the construction and utilization of the irrigation infrastructures – including tunnel – that have been mainly under the responsibility of Abdul Rojak without support and participation of other members of the community. (While the beneficiary of irrigation infrastructure are enjoying the present crop production at the cropping intensity of 300% annually with an average of 4.5 ton of un-husked dry rice per ha per crop.)

111 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Maintenance of the Irrigation Scheme During the life of Abdul Rojak, the entire operation and maintenance activities of irrigation system are personally conducted by him with some help from his close relatives, however, after he passed away on January 17, 2010, the farming community who are the beneficiary of Abdul Rojak Irrigation Scheme became aware about the urgent need to operate and maintain irrigation scheme on integrated basis through water user’s organization. Accordingly, the beneficiaries immediately established a forum referred to as “Community Awareness Forum for Taking Care Irrigation Heritage of “H. Abdul Rojak”. This forum was established on February 8, 2010, with an objective of maintaining and sustaining the irrigation scheme for appropriate utilization of the scheme through integration operation and maintenance amongst the related irrigation beneficiaries. Immediately after the establishment of this community forum, gradually the operation of irrigation system, which was previously under the responsibility of individual (Abdul Rojak as, the initiator), would become the responsibility of the group of beneficiaries as intended by the forum. It is expected that within not too long, the operation and maintenance of the Abdul Rojak Irrigation Area would be conducted by means of participatory irrigation management that has become strategic obsession of irrigation and water resources management in Indonesia. At present, the total member of the forum is 157 households, not only concerning irrigation, but also other water utilization purposes – in fact the total numbers of persons who become members are increasing. For immediate water management a group of 10 persons has GANY - INACID 112


Irrigation Tunneling

in Ancient Indonesia

already selected on democratic principle as irrigation operator with some small incentive (money) at about Rp 35,000/person/day (US$.4.12) at 8 hours work per day, given to them as incentive for operation the system – only if they work. For the time being, the chair person of the forum is relied to Aceng, as the senior assistant of Abdul Rojak during his life and Mas’ud, as the administrative assistant, and the son of Abdul Rojak has been agreed by the majority of the forum as the secretary of the newly established water users’ organization. At the initial stage, the operation and maintenance budget of irrigation scheme has been agreed upon among other to ask the farmer to contribute “in-kind” operation and maintenance budget at two ounces un-husked dry rice per bata (traditional measurement of about 50 m2) per harvesting or about 140 kg per hectare per harvesting. (With the present cropping intensity at about 300% the total contribution will be 420 kg of un-husked dry rice per hectare per year). This amount is presently still considered to be too low, but it may be increased gradually to follow the capacity of the farmers to pay for.

H. Appreciation from the Government Despite the achievement that had been obtained by Abdul Rojak in developing irrigation with his own initiative, the effort itself has been encouraging and gives motivation and self confidence to the local people to undertake similar effort for resolving irrigation problems encountered the rural community and their surroundings. Upon the remarkable success of Abdul Rojak to conduct irrigation development in his village, the government has given appreciation in terms of construction support for improvement the constructed infrastructures which are 113 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

hardly manageable by the farmer. Especially for the case of the Rojak Irrigation System, the government has given some awards in addition to the physical development support, among others as follows:

Figure 4.27. A Rojak receiving from President Soeharto, Presidential award Satya Lencana Pembangunan for remarkable achievement on infrastructural development

GANY - INACID 114


Irrigation Tunneling

in Ancient Indonesia

1. On May 5th 1987, the government awarded A Rojak with kalpataru (medal for special success of promoting sustainable environment) and special presidential award Satya Lencana Pembangunan for remarkable achievement on infrastructural development. 2. On June, 12th 1987, the provincial government of West Java Province awarded A Rojak with special appreciation in his capacity as the farmer for his successful effort to support self sufficiency of rice production as the staple diet of the people. 3. On October 16th 1987, A Rojak received special medal from Food Agricultural Organization (FAO) on the occasion of World Food Day in Bangkok, Thailand, recognizing his success in irrigation development. 4. On June 15 th 1987, the local government of Tasikmalaya District awarder A Rojak with special appreciation for his success to support sustainable irrigation and water resources utilization on the occasion of the World Day for Environment; and 5. Several other awards have been given to A Rojak for his remarkable achievement from the government as well as non government organization.

115 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

GANY - INACID 116


Irrigation Tunneling

in Ancient Indonesia

CHAPTER V

TUNNELING EXPERIENCE IN BATANG PANGIAN, TANAH DATAR DISTRICT, WEST SUMATRA PROVINCE

5.1. BRIEF REVIEW OF IRRIGATION IN WEST SUMATRA PROVINCE West Sumatra province is lying in the central part of Sumatra Island. It covers a total land area of 49,778 square kilometers, or about 2.59% of Indonesiaâ&#x20AC;&#x2122;s total land area. Based on population census in 2002, the total population of West Sumatra Province was 4,298,000 people with an annual average growth rate at about 0.63% between 1990 and 2000. (See Figure 5.1. General map of West Sumatra Province). Topographical conditions of this area are mostly undulating, ranging from medium to sharp. The plain in the west coast is very narrow. Therefore, it is impossible to develop large scale irrigation scheme in this area, for which, most of irrigation areas are consisted of small scale irrigation schemes. The main crop is paddy, which have been grown by application of irrigation technique for a long time and had been institutionalized, through generations, and yet still currently developing. Rice cultivation and its associated irrigation technique have been widely known since Hindu era. The overall paddy fields areas in 2002, was noted as 244,406 hectares, consisted of 191,196 hectares of irrigated rice fields, and

117 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

53,130 hectares of rain-fed paddy field. See Table 5.1. Irrigated Rice Field Areas by Irrigation System, 2002

Figure 5.1. General map of West Sumatra province

GANY - INACID 118


Irrigation Tunneling

in Ancient Indonesia

Table 5.1. Irrigated Rice Field Areas by Irrigation System, 2002 No.

Irrigation system

Area (ha)

1.

Technical Irrigation

37,149

2.

Semi Technical Irrigation

59,130

3.

Simple / Village Irrigation

94,917

4.

Rainfed Paddy fields

53,130

5.

Swamp Development Irrigation Total

80 244,406

Source: Agriculture Survey 2002, Central Bureau of Statistics.

Irrigation development and management techniques in West Sumatra, has a long history. In spite of the long term existence, the absence of historical evidence has not been allowing trace back the chronological existence of irrigation practice in this area, yet irrigation development and management is undoubtedly the most important heritage of Minangkabau Society of West Sumatra Province. Traditional irrigation has been developed quite amazingly, even though the technicality, materials, as well as agricultural practice were still fairly simple. Water power engineering has been practiced and developed by Minangkabau people since the middle of 14th century. Considering the generally undulating topographical condition, the people has been quite skillful to application of watermill technique to turn the wheel which is made from bamboo or wood for generating energy for a number of domestic purposes, including rice milling, water lifting, even for household electricity, today.

119 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Another distinct characteristic of irrigated agricultural heritage in West Sumatra is the Paraku with Irigasi Takuak traditional irrigation management system which is still practiced today. Irrigation development and management has been implemented through traditional organization called Tuo Banda. Tuo Banda also stands for the Chairman who is responsible to conduct operation and maintenance of irrigation scheme. Tuo Banda must take care of the canal maintenance, and the beginning of every planting season, to coordinate farmers who are obligated to participate in the program to maintain irrigation infrastructure, especially to maintain Kapalo Banda (Weir) and main system, as well as other related infrastructures such us tunnel etc., despite that this technique had been very old and presently not so many information about tunneling technique available in the community today. 5.2 TRADITIONAL IRRIGATION AND TUNNELING Based on historical evidences, irrigation development in West Sumatra has been developed since the Hindu Era. For instance, an evidence of "banda bapahek" near Suroaso Village, is an ancient canal from the Hindu Era, located at the stone hill â&#x20AC;&#x201C; there are some inscription at the wall explaining about the history of the irrigation infrastructures. The stone relief was written in two languages (Sanskrit and other that had yet not known) but the script has not been interpreted. Despite the absence of study and information about traditional irrigation and tunneling technique, the relief at least explained that the ancient community in West Sumatra had long been developed and managed irrigation technique for agricultural purposes.

GANY - INACID 120


Irrigation Tunneling

in Ancient Indonesia

Traditional Irrigation and Tunneling of Batang Pangian: An example of ancient irrigation scheme with tunnel which was developed since the ancient time and still in use today is called in local language as ngalau gate (the gate of the cave). Despite that the tunnel has already improved by changing the tunnel into large pipe (65cm diameter), but the original tunnel had indeed contribute much to the prosperity of the people in the area. (See Figure 5.2. General location map of Pangian Scheme.

Figure 5.2. General location map of Batang Pangian Irrigation Scheme, Tanah Datar District, West Sumatra Province

This scheme is now included in the management of the government managed irrigation system named as Sangki-I Irrigation area, with the discharge of about 600 Liter per

121 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

second, with length of one kilo meter, replacing the original tunnel length of more than 400 meters. Based on information at interview with the local leaders (Datuk Bandaro from Nagari Pangian and Datuk Bijayo from Lubuk Jantan region), the irrigated farming system in this area had been inherited from generation to generation for decades though they do not have an exact time when the irrigation scheme was initially developed. The water source of the Batang Pangian Irrigation Scheme was taken from the Pangian Cave by making weir of the underground river, and diverting the water through a tunnel of more than 400 meter long. The original scheme was still operated till 1970â&#x20AC;&#x2122;s, but the tunnel was hampered by problem due to earthquake.

Figure 5.3. The Pangian Canal at the downstream of tunnel

GANY - INACID 122


Irrigation Tunneling

in Ancient Indonesia

Figure 5.4. Aeration hole of the tunnel for O&M location at the center of the tunnel 200m downstream of weir (1.5 x 2m)

Operation and maintenance: The farmersâ&#x20AC;&#x2122; activities to operate and maintain the scheme under the coordination of the traditional government referred to as Wali Nagari and leaded by the so called Tuo Banda (the community leader who responsible to coordinate irrigation management). The maintenance activities conducted by means of mutual aid works, usually at the beginning of planting season with certain traditional ceremonies. Irrigation infrastructures are mostly setup by using simple structures and materials. For instance the weir construction usually made of loose rip-rap with bamboo peg in such a way that the weir will automatically collapsed when hit by large flood, so the flood water and garbage will not enter the tunnel, which difficult to clean, while the simple structure could be easily restored by them after the flood season. Therefore, the canal and 123 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

tunnel will always be prevented from damages due to flooding and/or disturbance of accumulation of garbage. Based on traditional practice, the void of the loose riprap should not be closed with impervious layer. This is to allow the water flows downstream for downstream users within the river system. (Thus the simple technique which was implemented by the traditional farmers accommodates the environmentally friendly operation and maintenance of irrigation schemes). Construction and operation of infrastructures: Despite of the limitation of construction techniques and allocation of resources, the ancient irrigated agricultural generation has already aware about the demand for pursuing effective irrigation development and management by means of proper integration between physical system (hardware) which facilitate the water allocation, transportation and distribution, with another software system such as human resources, and management information system. As the matter of fact, during the pass time, the implementation of irrigation operation at the Batang Pagian integrated irrigation water management had already adopted, including the water right management by traditional community. These include arrangement of right and responsibility of the water user and other related stakeholders, and conflict resolution on operation and maintenance (role sharing, risk sharing, and profit sharing for water management). So far there is no information about the initial construction of irrigation infrastructures of the Batang Pangian irrigation scheme. They can only estimate that the development must have been conducted before the Hindu Era, from South India which was much older than the Hindu Era on Java Island. The Hindu Migrants from South India was approaching Sumatra from West to the GANY - INACID 124


Irrigation Tunneling

in Ancient Indonesia

center of Minangkabau ancient kingdom of Western Sumatra Island. Unfortunately, so far there is no study concerning the history of irrigation in the ancient Sumatra area that could explain this phenomenon.

Figure 5.5. The reconstruction in 1977 was not effective

In 1977 the Batang Pangian Irrigation Scheme was reconstructed by the government through special manpower taskforce program by improving the weir and irrigation canal along the steep slope parallel with the tunnel alignment. The result of this taskforce program was not so successful and the canal was not perfectly restored. In 1983 the government decided to restore the scheme by changing the function of the 400 meters tunnel with close conduit channel at the diameter of 65 cm pipe along the steep valley parallel with the tunnel alignment but turning around with the total length of 1.10 km.

125 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 5.6. In 1983 the government decided to restore the scheme by changing the function of the 400 meters tunnel with close conduit channel at the diameter of 65 cm at the total length of 1.10 km.

Despite that the tunnel is no longer utilized, till present, however the Batang Pangian Irrigation Scheme is still under the efficient operation to irrigate a total area of 550 ha. Under the autonomous government regulation, however there is a tendency of acceleration of scheme deterioration because the local government of Tanah Datar District has not had adequate financial capacity to operate and maintain the system, which was previously supported by the Provincial and Central government before enactment of local autonomy for irrigation of the area less than 1,000 ha. GANY - INACID 126


Irrigation Tunneling

in Ancient Indonesia

Figure 5.7. The outlet of the 65 cm pipe and diversion box after the tunnel have been replace with 1.1km pipe

A study conducted by Dr, John Sterling Ambler in (1989) stated in his dissertation entitled “Management of Small scale Irrigation in West Sumatera, Indonesia” mentioned slightly about the history of irrigation in west Sumatra, including a comprehensive illustration about Batang Pangian Simple Irrigation Scheme, taking water from the Pangian Cave by tunnel. He stated in his dissertation about the farmers’ group participation but there is no information about technical design and construction aspects of the Batang Pangian irrigation tunnel. Also, there is no information about the time when the Batang Pangian Tunnel was constructed.

127 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 5.8. The 65 cm diameter of pipe replacing the tunnel is now suffered from damage due to the lack of maintenance

Thus the Batang Pangian Irrigation infrastructures including tunnel had been developed and maintained with the strong support of traditional organization since the ancient time. Through the application of traditional integrated irrigation management, it has been proven that irrigation development and management had been sustained for hundreds of years, and still existed today though the spirit of integrated and participatory approach is seemingly become disappearing through intervention of modernization.

GANY - INACID 128


Irrigation Tunneling

in Ancient Indonesia

CHAPTER VI

CAPACITY BUIDING, OPERATION AND MAINTENANCE 6.1. INDIGENOUS TECHNOLOGY As far as the traditional tunneling technique is concerned, there is no information about training or source of technical knowledge that the tunnel builder had. Based on interview of several undhagi awungan (tunnel expert), all of the stating that they had never has training neither no trainer that guide them to know the tunneling technology. It is assumed that the knowledge had been based on indigenous capacity that has long been descended through generation through actual experience, and the elder persons who have more experience will identify the young workers who have talent and let them learn from experience, and later on become his future successor. Unlike the present situation where a lot of apprentice school could teach irrigation technique, geodesy, geology and geography till advanced education at the university level. Thus the tunneling technology has been disseminated merely by means indigenous practice from generation to generation. Unfortunately the present irrigation development and management are gradually conducted by applying updated technology, despite that they are still unable to fully implement them, for one or other reasons.

129 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Being the case the traditional community that are located in the remote area, would always pay attention to the indigenous tunneling techniques, though the elder generations are gradually getting old and cannot continuously concentrate on maintaining indigenous technical practices. In reality there are several indigenous practices in terms of manual for carrying out particular technique, but these kinds of techniques are merely descended from generation to generation orally. And practically no written literatures where we can learn about the related technique with irrigated agriculture. Learning from instinct: From most undhagi aungan (tunneling experts) who are still exist, but most of them become too old now, none of them sated if they used to learn or attended some sort of training before. In fact, they only come to know after learning by themselves consistently with full of attention and enthusiasm. They were mostly stating their learning process by contemplating with particular cases or problems they come across, and mostly are anxious to learn by sustaining full praying and submission to the Almighty God. They are fully believed that by consistently working, contemplating and praying to the Almighty God, they will be blessed by instinct as well as practical solution on every problem they are encountered. In Bali for instance, the main principle they are mostly have are â&#x20AC;&#x153;CATUR GURUâ&#x20AC;? principles, which are five teachers in their life; 1). Guru Rupaka (mother and father); 2). Guru Wisesa (the government); 3). Guru Pengajian (the the actual teacher who teach at the school); and 4). Guru Swadiaya (self teaching with some kind of instinct from God).

GANY - INACID 130


Irrigation Tunneling

in Ancient Indonesia

Thus, with absence of teaching from mother and father, from the government; and with no education from the government, the remaining teacher they rely on in Guru Swadiaya or self teaching with the help of instinct from God. So they will learn from this teacher. Beside, the Balinese strongly belief that the Almighty God in his manifestation to teach the people known is commonly known by them as “Bhatara Guru”, or the genuine teacher. Thus they do not learn from someone, but merely by contemplating on the problems they are currently facing, then God will give them idea through instinct. The case of Majalengka: Similarly, the author tried to interview the lady (Mrs. Yuyu Yusanah) for the case of tunneling experience in the remote village at Majalengka District, West Java Province, she honestly mentioned that she is illiterate lady, stay at the remote village without electricity, without Radio or TV communication, without transportation, without reference and without experience to leave her remote hamlet. When I asked her if she had technical guidance from someone, she only answered that; “every idea she had, was coming from within”. This include the use of her only mirror at home for reflecting the sun shine for lighting the tunnel during construction excavation and post construction Operation and Maintenance, she said that she only decided the idea when she found it difficult to work inside the tunnel without lighting. As the matter of fact, the people in her community were considered her as a crazy woman when she started the idea of tunnel excavation, some of the community members were suggested to isolate her for having such strange idea and behavior that the common people in her hamlet do not understand. 131 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

At the first few months of the excavation, no one would come to help her, except her husband, though her husband was also curious about the strange idea that his wife was suggesting and implementing. Only after the excavation work had been conducted for quite deep, the people gradually came to help her, though still with the feeling of suspicious.

The case of Lombok Island: For the case of Lombok Island, the person who are usually asked to make design and construct tunnels are considered by the local community as witch engineer who conduct the process from design construction and operation as well as maintenance by instinct or some kind of extra sensory perception. They usually consist of group of five to ten people, coordinated by the witch engineer. All of the decisions are decided based on instinct after series of traditional ritual processing and contemplating. During the ritual contemplation they will decide the starting date of every stage of tunnel development. So does the decision to set up the tunnel alignment and direction of the tunnel that they will construct. The workers who are not the member of the group are not allowed to involve in the tunneling excavation. So the main principle of indigenous tunneling technique is based on “planning as you go”, not “go as you plan”, and all decision are guided by instinct after conducting traditional ritual processing. Today, however such “witch engineers” are no longer available, and there is no effort to conduct capacity building for sustaining the indigenous tunneling technique. The case of Batang Pangian West Sumatra: The Batang Pangian Irrigation infrastructures including tunnel had GANY - INACID 132


Irrigation Tunneling

in Ancient Indonesia

been developed and maintained with the strong support of traditional organization since the ancient time. Through the application of traditional integrated irrigation development and management, it has been proven that irrigation development and management had been sustained for hundreds of years, and still existed today though the spirit of integrated and participatory approach is seemingly become gradually disappearing through intervention of modernization.

Traditional Ritual Processing: As previously stated that the tunnelling processing is strictly related with traditional ritual processing, which is nothing but effort to pray to the almighty God for maintaining safety, prosperity and success in their tunnelling effort. In Bali, for instance, one of the most important rituals is called bebanten (upakara). In fact they do not want to distract the balance of natural system without making upakara or bebanten. This ritual is generally conducted when they want to start the daily work and or if they have to make change to the condition that had been decided every day. The traditional ritual processing are actually varied from place to place and â&#x20AC;?witch engineerâ&#x20AC;?, but principally, they are conducting religious praying for asking safety, prosperity and success from the Almighty God for every phase of efforts they are undertaking.

Event of traditional ritual processing: Despite of the different religion or belief they have, the ritual processing almost similar to the ritual that the Balinese doing: (1) The beginning of land surveying and staking out; (2) At the beginning of tunnel excavation; (3) After completion 133 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

partly or the whole system (melepas); (4) Every day at the beginning of working, and also at the special day they consider sacral (kramat); (5) At the time when they have significant problem to be solved. In Bali, the traditional ritual processing is more complicated than in other places, including series of prerequisites and magic spellings.

6.2. OPERATION AND MAINTENANCE Despite the tunneling technique has existed in Indonesia since the ancient time, it is apparent that the operation of the existing tunnel are mostly under the sustainable operation from generation to generation. So far, there is no record where the tunnels reported damaged even for the case of huge earthquake. So far, the O&M problems they are having are related to sedimentation, and water distribution during the season of scarcity, including the excessive percolation and water losses at the tunnel along the porous soil. For the case of sedimentation, it is apparent that most tunnels are set up at an optimum longitudinal slope in such a way that the water velocity is large enough but still not deteriorating or endanger the cross section of the tunnel. For the case of routine inspection, they are mostly conducting group visit through the tunnel or through the aeration hole if necessary. They will immediate conduct prevention or restoration works if they found during inspection parts of the tunnel that necessary to undertake special maintenance or restoration work. Most recently after the countryâ&#x20AC;&#x2122;s independence the operation and maintenance of irrigation networks are becoming more

GANY - INACID 134


Irrigation Tunneling

in Ancient Indonesia

and more difficult due to the expansion of irrigation area with limit O&M budget as well as personnel’s. Considering the difficulty of the farmer to sustain the operation and maintenance of irrigation schemes, since 1980’s the government has been taking initiative to assist the rehabilitation works as well operation and maintenance works through the “small-medium scale” irrigation construction and rehabilitation works. Especially in the small island where irrigation scheme are mostly of small and medium scheme, this government program has been prioritized significantly. In Bali Island for instance, the entire irrigation schemes which consisted of small and medium, are covering a total area of 100,000 ha with the total length of traditional tunnel of 96.285 km or about 15% of the total length of irrigation canals (Total canals 612,842 km, consisted of unlined irrigation canal 571,905 m; and lined canal 40,937 m – Based on Inventory of irrigation, PU, Bali Province, 1979). At present, the total length of tunnels and close conduits in Bali based on inventory is about 300 km (DPU Province of Bali, 2009). These schemes are currently under the management of the government through the Central, Provinces and District Level Public Works Irrigation Services following the Government regulation No. 20/2008 about irrigation. (Irrigation area < 1,000 ha per unit, under the responsibility of the District Government; Irrigation area between 1,000 ha and 3,000 ha per unit, under the responsibility of the Provincial Government; and > 3,000 ha under the responsibility of the Central Government). See Table 6.1., List of irrigation tunnels per District that are currently managed by the Bali Provincial Public Work Services for more detail example.

135 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Table 6.1. List of irrigation tunnels per District in Bali

No.

District

Primary Canal (m) 5,416

Secondary Total (m) canal (m) 581 5,997

1.

Buleleng

2.

Jemberana

8,458

458

8,916

3.

Tabunan

7,459

-

7,459

4.

Badung

17,100

1,200

18,300

5.

Gianyar

29,001

1,200

30,201

6.

Bangli

-

6,280

6,280

7.

Klungkung

10.502

300

10,802

8.

Karangasem

7.130

1200

8,330

85,066

11,219

96,285

Total

Source: Dinas Pekerjaan Umum Prop. Dati II Bali Tahun 1979, in Suadnya, BE., March 1981

Rotational water delivery during the scarcity season: In relation with traditional tunnel design, operation of irrigation scheme has been considered during the scarcity season. Especially during the water scarcity in the dry season, the water distribution for Subak members is conducted on rotational basis. The rotational water distribution system is conducted on mutual consensus. All water disputes are settled down with judicious arrangement among the Subak members themselves. The cropping schedule is also determined by the Subak members themselves by clearly stating the water distribution obligation. Therefore the tunnel system within irrigation networks should be able to adjust with operational system with the discharge at the scarcity season. In the determination of cropping pattern and water GANY - INACID 136


Irrigation Tunneling

in Ancient Indonesia

delivery schedule, in this condition, they adopt three cropping rotations â&#x20AC;&#x201C; and hence water distribution â&#x20AC;&#x201C; schedules: (1) the Ngulu; (2) the Maongin; and (3) the Ngesep. The Ngulu means water distribution from the head, which is referred to as the water delivery for the crop rotation which starts earlier (between November and December). The Maongin means water delivery from the neck, which is referred as to the second crop rotation starts two months later (between January and February). The Ngesep means late, which is referred to as the third crop rotation which is implemented between March and April. In practice, this crop rotation is very effective for managing the staggered planting date, so that the crops do not consume water simultaneously, and hence the water constraint can be minimized, and the tunnel can accommodate the discharge for each rotational unit. In comparison with the most recent irrigated agricultural techniques â&#x20AC;&#x201C; that the people knows today, it is quite amazing to observe the fact that the traditional agricultural practices under the Subak system are perfectly confirmed with the current (modern) irrigation application for low-land paddy. For example, the field water requirement which has long been practiced by the traditional Subak is perfectly comparable with the most recent calculation on the ultimate field water distribution demand for low-land paddy. In addition, the modern agricultural research has demonstrated that the occasional necessity of 24 hours per day water distribution is recommended for optimum growth of paddy during the early growing stage. This magnitude is also consistent with the maximum design of tunnel, and the excess discharge if any, can be spilled through the horizontal aeration hole.

137 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

One of the unique feature of the ancient irrigation water management, in ancient Indonesia, particularly in Bali, is that the water allocation for each irrigation unit must be distributed equally (disregarding the amount of water availability) to all water user in that particular irrigation unit, without necessary to use the lock water gates. Hence the design of tunnel discharge has to be consistent with the water requirement for larger area by means of multiplication of the one tek-tek water flow standard. In practice, this simple water measurement procedure is widely implemented by the Subak and other ancient water users' associations without ever being tempted to use more water than they are actually deserved. The ancient water user community members are bound together in some sort of traditional entity or feeling of togetherness in the society. In addition, they are tied up with social as well as religious norms so intensely that taking an excessive amount of water makes no sense to them as the beneficiaries. Similarly, the simple water management as well as water distribution in terms of rotational water distribution has long been practiced in other palaces in Indonesia since the ancient time. As the matter of fact, this sustainable water management practice has long been implemented by the Subak farmers in Bali and other traditional water user organizations in Indonesia through generations.

GANY - INACID 138


Irrigation Tunneling

in Ancient Indonesia

CHAPTER VII

LESSON LEARNT Taking series of lessons from the long time experiences on traditional irrigated agriculture in Indonesia since the ancient time, it has been concluded that the simpler the approach the easier the farmer to participate and adopt the appropriate technicalities and the more sustainable would be the irrigated agricultural practices. The ancient irrigated agricultural practices in Indonesia for instance, Subak in Bali, Keujreun Blang in Aceh Special Province, Tuo Banda in West Sumatra, Raja Bondar in Nothern Sumatra, Mitra Cai in West Java, Dharma Tirto in Central Java, Tudang Sipulung in South Sulawesi, Mantri Siring in South Sumatra, Ili-ili in Lampung has been in existence and practiced from generation to generation for hundreds of years, and amazingly still continuously practiced today in modern Indonesia. As the matter of fact, there are various principles of sustainable traditional techniques that are still relevant to be adapted by any similar rural farming circumstances in this modern world. These include rotational water distribution during the water scarcity season, traditional technique on water measurement devices, traditional environmentally friendly agricultural practices and traditional tunneling technology which has been the subject of discussion in somewhat elaborated terms through the chapters of this book. 139 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

The working arrangement of farming activities in ancient Indonesia, including construction of Tunnel has been generally based on traditional organizational arrangement, by taking the natural mechanism of human body into consideration, and converted into the rationale of group membership on mutual aid approach referred to as “gotong-royong” principle. The main principle built into this system is based on the ability to regulate the suitable techniques, time, space and environment in order to meet the livelihood of the people through "harmonious-togetherness" principle. The basic techniques are incorporated with the simplicity principles, so that every members of the community are able to adopt and/or apply the technique without involving sophisticated learning process. This includes the use of human body organ’s sizes for determining the size, distance or length of things. The measurement, which were adopted by the traditional technician, till today are still utilized effectively for non precise measurement. Taking into consideration of Yuyu Yusanah’s and Abdul Rojak’s experiences, it is obvious that the local villagers are having high initiative to conduct irrigation development, though they are lacking for technical knowledge and capital. Especially after the construction has been completed, they are willing to participate on operating and maintaining the system. In this regards, the local authority must aware that the sense of belonging of the farmer on irrigation infrastructures is very important for them to continuously pay effort to develop, operate and maintain the infrastructures. However, water management is usually constrained by the lack of knowledge at the initial stage. Therefore, it is essential for the local government to continuously providing for technical guidance on water utilization as well as agricultural extension services. GANY - INACID 140


Irrigation Tunneling

in Ancient Indonesia

For maintaining the tunnel, of Yuyu Yusanahâ&#x20AC;&#x2122;s, the farmer has been constrained by the difficulty to clean the sediment that deposited inside the tunnel, because the space is not wide enough to give allowance to work cleaning the sediment inside the tunnel, at the same time they do not convenient to work inside the tunnel without lighting facility. From the previous experience during the process of tunnel excavation, we learned that the lighting for working inside the tunnel was using cupboard mirror for reflecting the sun shine. This was done by asking one person to hold the mirror, so it continuously reflecting the sun light while others working to excavate the tunnel inside. The spoil of excavation was transported out by using bamboo plaited container and pulling it with rope in and out. This experience had inspired the technical staff of the Research Institute of the Ministry of Public Work to develop simple tools for the farmer to maintain the tunnel and to reflect the sunshine for lighting inside the tunnel while working. See Figure 7.1., the sketch for detail mechanism of the sun light reflector, and Figure 7.2., Photograph of the sun light reflector, set up at the rice field, just at the downstream of the tunnel. The sketch of the sediment cleaning kit is presented in Figure 7.3., and photograph of it operational utilization of the cleaning kit in Figure 7.4. From Figure 7.1., we can see that the three mirrors can be set up to concentrate into one point so it becomes brighter than the single mirror, and it should not be hold by a person like they did previously.

141 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Figure 7.1. The sketch for detail mechanism of the sun light reflector

Figure 7.2. Photograph of the sun light reflector, at the field

GANY - INACID 142


Irrigation Tunneling

in Ancient Indonesia

Figure 7.3. The sketch of the sediment cleaning kit

Figure 7.4. Photograph of operational use of the cleaning kit

From Figure 7.3., and Figure 7.4., above, it can be seen the operational mechanism and it operational utilization for cleaning sediment without entering the tunnel. The lighting inside the tunnel is using the sun shine reflector. 143 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

GANY - INACID 144


Irrigation Tunneling

in Ancient Indonesia

CHAPTER VIII

CONCLUSION Historically, irrigation tunneling in Indonesia has been practiced since the ancient time. However, no evidence had been indicating the exact it was initially practiced. Tunneling technique, utilizing simple measurement devices, traditional environmentally friendly technique and excavation were using simple tools and time allocation for construction at an average of about three years for the average size of tunnel with the length of about one km. The location of tunnel practices are mostly in Bali, Lombok and parts of Java Islands under the arid and semi arid zones, with undulating topography, mostly at hilly areas, highly populated areas with limited agricultural land, and frequently suffered from water scarcity. The highlights of technology that are practiced by the ancient irrigation water user are â&#x20AC;&#x153;simplicity principleâ&#x20AC;?. They were mostly confident that simpler the approach the easier the farmer to participate and adopt the techniques and the more sustainable irrigated agricultural practices, including tunneling application and other technical as well as well as non technical aspects of irrigation development and management. The main principle they adopted in agricultural was the ability to regulate the suitable techniques, time, space and environment through harmonious-togetherness among the members of organization; among human and

145 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

environment, as well as human and the Creator or the God. Therefore all activities must be started with ritual ceremonies for asking for safety, success and prosperity to the Almighty God. The most common problems they faced at the construction and excavation of tunnel among others: (1) When the tunnel axis encountered with hard soil material, rock, boulders at the same location with the tunnel alignment; (2) When the excavation from two direction in which the axis of the tunnel is not met consistently; (3) When the excavation conducted along the soft soil; (4) when the excavation encountered with soil cracking, high porosity and so on. However, there were mostly familiar with such problems and ready to resolve, either by avoiding such intervention or by turning the alignment to other direction or by directly working out to break up the hard soil, boulders or rock with traditional technique, though it will extend the excavation time. Concerning the sustainability of operation and maintenance of the tunnel and other infrastructures, despite the fact that traditional tunneling technique has been existed since the ancient time, however, they are mostly under the sustainable condition, even till today. As the matter of fact, so far there is no record where the tunnels reported damaged, even for the case of huge earthquakes. The operation and maintenance problems are commonly related to sedimentation, and water distribution during the season of water scarcity (dry season), including high percolation and excessive water losses. They are mostly having skilful experience to deal with such operation and maintenance problem. However, after the countries independence the Operation and Maintenance of irrigation networks are becoming more and more difficult due to the expansion of GANY - INACID 146


Irrigation Tunneling

in Ancient Indonesia

irrigation areas to reach the remote areas, with limited Operation and Maintenance budget as well as personnel who are mostly became older without adequate successors from young generation. The younger generation are mostly reluctant to work in irrigated agricultural sector. In Bali Island for instance, all irrigation areas are consisted of small and medium irrigation category, with the total area of about 100,000 ha are currently suffered from land conversion problem from irrigated agricultural area to industrial, urban settlement and other non agricultural areas. While the traditional tunnel infrastructures with the total length of about 100 km (1974), and based on the most recent inventory, is about 300 km including the close conduit, DPU, 2009) but currently under the scarcity of personnel and resources allocations for continuously conducting appropriate operation and maintenance. From the case of Batang Pangian traditional Irrigation Schemes including tunnel, we learned that the infrastructures had been developed and maintained with the strong support of traditional organization since the ancient time. Through the application of traditional integrated irrigation development and management, it has been evident that irrigation development and management had been sustained for hundreds of years, and still existed today though the spirit of integrated and participatory approach is seemingly become gradually disappearing through intervention of modernization.

147 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

BIBLIOGRAPHY Adi, I. Gede., 1972. Sistim Subak di Kecamatan Kesiman. Unpublished thesis, Faculty of Laws and Social Science, University of Udayana, Denpasar, Bali. Ambler, John Sterling, 1989. “Management of Small Scale Irrigation in West Sumatera, Indonesia”, 592 pages. Ph.D. Dissertation, The Ford Foundation. Ardjana, Ngk. Njm. Rai, 1972. Organisasi Subak di Desa Pejeng. Unpublished thesis, Faculty of Laws and Social Sciences, University of Udayana, Denpasar, Bali. Angoedi, Abdullah., 1984. “Sejarah Irigasi di Indonesia” Anonim; 19 ??. Indik Empelan (Kepustakaan Geria Gebaang, Tampaksiring, Bali. Atmanadhi, BA. Asha Kosala - Kosali Gumi. Bali, PRIS, 1983. Subak System in Bali: A Brief Description, Bali Provincial Public Works Services, July 1983. Dinas P.U. Propinsi Bali, 1972. Sekelumit Tentang Subak sebagai Sistim Pengairan di Bali, (unpublished report). Dinas P.U. Provinsi Bali, 1972. Masalah Pengairan dan Pemanfaatan Air Irigasi bagi Pertanian di Daerah Propinsi Bali, (unpublished report). Dinas P.U. Provinsi Bali, 2009. Daftar Inventarisasi Jaringan Irigasi di Provinsi Bali, 20019 (unpublished report). Gany, A.H.A., and Halli, S.S., 1993. Land Development and Transmigrant Farmers in Southern Sumatra, Indonesia. In International Migration. Quarterly Review Vol. XXXI No. 4, 1993. International Organization for Migration (IOM), PO Box 71, 1211 Geneva, Switzerland.

GANY - INACID 148


Irrigation Tunneling

in Ancient Indonesia

Gany, A.H.A. and Zakaria, Ir. F., 1975 Persubakan di Bali. A Report for the Provincial Government of Lampung, 1975. Gany, A.H.A., 1994. “Integrated Water Resources Management” Published in Indonesian Language, Majalah Pekerjaan Umum Edisi Khusus No. 03/1994/ XXVII, Jakarta. ____, 1989. Field Water Management Impacts on the New Irrigated Area. In Rydzewski J.R. (ed), Irrigation, Theory and Practice, John Wiley and Son. Ltd. & Pentech Press.London. ____, 1993. The irrigation Based Transmigration Program in Indonesia. Ph.D. Dissertation, University of Manitoba, Winnipeg, Canada. ____, 2001. The Amazing Facts of Potent Women’s Participation on Indigenous Irrigation Practices in Modern Era, Research Institute for Water Resources, Developmen Agency, Minister of Settlement and Regional Infrastructures, 2001. ____, 2001. Subak Irrigation System in Bali: An Ancient Heritage of Prticipatory Irrigation Management in Modern Indonesia, July 21, 2001. ____, Syaiful Mahdi, and Effendi Padandaran, 2004. Irrigation History of Indonesia. Ministry of Settlement and Regional Infrastructures in Collaboration with: The Indonesian National Committee of ICID (INACID), August 2004. Goris, 19??. Sejarah Bali Kuna. Grader, C.J., 1960. The Irrigation System in the Region of Jembrana, Bali, Studies of Life, Thought and Ritual. Selected Studies on Indonesia, Vol. V. Les Editions A. Manteau S.A., Bruxelles W. van Hoeve Ltd. The Hague and Bandung. Edited by W.F. Wertheim et.al. IPB, and University of Udayana, 1974. Subak, Organisasi Tata Guna Air pada Tingkat Desa di Bali, Institute of

149 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

Agriculture Bogor, And University of Udayana, Bali, November 1974. Kantor Agama Hindu, 19?? dan Srhi Tatwa maka Dharma Budha Kabupaten Badung Pemaculan. Kordinator Perguruan Tinggi VI., 1972. Laporan Penelitian tentang strategi Pembangunan Daerah untuk Propinsi Bali., Vol. II., Surabaya, Indonesia. Park, Kee Sung, 1976. Subak Irrigation System in Bali, Indonesia. Japan International Cooperation Agency (JICA), 1976. Persatuan Sarjana Rakyat Indonesia Singaraja, 1969. Subak Sebagai Sistim Pengairan di Bali.Reproduced by Dinas P.U. Propinsi Bali. P.N. Virama Karya, 1971., Laporan Reconnaissance Pola Induk Tata Air Pulau Bali.Virama Karya, Jakarta. Prosida, 1972. Subak Kumpul di Bali, Prosida, Jakarta. Suadnya, I Gusti Made, 1981. Awungan (Terowongan), Bagian Pengairan Dinas Pekerjaan Umum Daerah Tingkat I Bali, 26 March, 1981. Suadnya, I Gusti Made, 1990. Mengenal Subhak, Sub Dinas Pengairan Dinas PU Provinsi Daerah Tingkat I Bali, February 1990. Teken, I.B., 1967. Organisasi Pengairan Pedesaan Subak di Bali. A case study: Subak in Desa Luwus, Tabanan, Bali., Bogor Institute of Agriculture. University of Udayana, Denpasar, Bali., 1975. Laporan Survey Persubakan di Bali (October 1974 - March 1975). Winaya, P. Djapa, 1973. Organization of Water Association in Bali., A paper specially prepared and presented as a lecture for the American Students from the Lewis and Clarke College, Oregon, U.S.A., at the Udayana University, Denpasar, Bali. Wedante, I.G Ngurah., 1957. Subak di Bali. An Unpublished Study for "Sekolah Pendidikan

GANY - INACID 150


Irrigation Tunneling

in Ancient Indonesia

Kemasyarakatan Negeri 4 tahun", Surakarta, Central Java.

151 GANY - INACID


Irrigation Tunneling

in Ancient Indonesia

GANY - INACID 152

Irrigation Tunneling in Ancient Indonesia  

This book explains the methodology that had been utilized for tunnel excavations, including post construction operation and maintenance of t...