Overview of small tank cascades: Evolution, present status and future scenariosDr. P.B.Dharmasena
Presentation made at Policy Dialogue on Restoration and Management of
Small Tank Cascade Systems on 14 February, 2017 at
Bandaranaike Centre for International Studies (BCIS), Colombo
This is lesson 1 for Three Day Residential Training Workshop on Cascade Water Resources Development and Management prepared for Climate Resilient Integrated Water Management Project Project
This is lesson 6 of IKS taught to Master level students on Indigenous Irrigation Systems at the Faculty of Agriculture, Rajarata University of Sri Lanka
This is lesson 2 for Three Day Residential Training Workshop on Cascade Water Resources Development and Management prepared for Climate Resilient Integrated Water Management Project Project
This presentation explains the ancient master plan of water resources management, tank cascades - spatial distribution, definitions, and importance, ecosystem services, and functions and planning procedures.
Overview of small tank cascades: Evolution, present status and future scenariosDr. P.B.Dharmasena
Presentation made at Policy Dialogue on Restoration and Management of
Small Tank Cascade Systems on 14 February, 2017 at
Bandaranaike Centre for International Studies (BCIS), Colombo
This is lesson 1 for Three Day Residential Training Workshop on Cascade Water Resources Development and Management prepared for Climate Resilient Integrated Water Management Project Project
This is lesson 6 of IKS taught to Master level students on Indigenous Irrigation Systems at the Faculty of Agriculture, Rajarata University of Sri Lanka
This is lesson 2 for Three Day Residential Training Workshop on Cascade Water Resources Development and Management prepared for Climate Resilient Integrated Water Management Project Project
This presentation explains the ancient master plan of water resources management, tank cascades - spatial distribution, definitions, and importance, ecosystem services, and functions and planning procedures.
The presentation includes the technical knowledge had in the past in Sri Lanka at various level of development and most of them can be used with some modifications at present
Traditional water harvesting in Central Highlands of India.The presentation shows various methods employed for water conservation and recharging in Central India (Rajasthan, MadhyaPradesh,Chhattisgadh)
Rainwater harvesting is one of the surest ways of reducing our dependence on secondary sources of water like lakes or rivers. As there is a limted supply of water available to man, it is important that he learns to recycle and reuse water as well. This is where rainwater harvesting becomes important. The presentation that follows will allow a teacher to explain in simple terms what rainwater harvesting is, why it should be made popular, and how it is useful. Through this presentation children will also learn about some of the popular rainwater harvesting systems prevelant in the driest region of this country—Rajasthan, and surprisingly even the wettest—the Northeast. Why does a rain rich region like the Northeast need to harvest rainwater? Find out the answer to this and more through this PPT.
Lessons adoptable from ancient water management of Sri LankaDr. P.B.Dharmasena
The presentation discussed the objectives of ancient water management in Sri Lanka as:
1. Irrigation for food production
2. Human needs (settlement, drinking water, bathing, domestic needs etc.)
3. Rainwater harvesting systems
4. Environmental existence (flora, fauna etc.)
5. Building cities (Anuradhapura, Sigiriya etc.)
6. Urban planning
7. Basis for administrative boundaries
8. Mitigation of natural disasters (drought, flood, cyclone, epidemics etc.)
Managing tank cascades in the dry zone for Optimum supplyDr. P.B.Dharmasena
Presentation made at the seminar organized
by IEPSL on 19th August 2011 at Waters Edge, Colombo to explain the importance of tank cascade management in sustainable water resources management
This is the third lecture of the course 'Irrigation based Agro-ecosystems' conducted at the Faculty of Social Sciences and Humanities of the Rajarata University of Sri Lanka
Presentation made at the Discussion Forum on Cascade Development in NCP, NP and NWP held on 26th November 2013 at the Conference Room of the
Uma Oya Multipurpose Development Project, Ministry of Irrigation & Water Resources Management, No. 26, Jawatte Road, Colombo 5
The irrigation works in ancient Sri Lanka, the earliest dating from about 300 BCE, in the reign of King Pandukabhaya and under continuous development for the next thousand years, were some of the most complex irrigation systems of the ancient world.
The lecture contains aspects such as Ancient Water Resources Planning, Water shortage, or water wastage in Sri Lanka?, Network of tanks and streams in the form of cascades, Tank-village Ecosystem, Patial desilting concept
This is the 3rd lesson taught to students of B.A. (General) at the Faculty of Social Sciences and Humanities, Rajarata University of Sri Lanka, under the course; Water Resources Planning and Development
This is a presentation made to IESL members on 29th December 2019 at The Sigiriya Air Force premises.
Water resources management master plan in Sri Lanka includes not only irrigation but many more purposes.
This is the part 1 of 5th lesson in the course 'Traditional Knowledge in Sri Lankan Agriculture' taught at the Faculty of Agriculture, Rajarata University of Sri Lanka
The presentation includes the technical knowledge had in the past in Sri Lanka at various level of development and most of them can be used with some modifications at present
Traditional water harvesting in Central Highlands of India.The presentation shows various methods employed for water conservation and recharging in Central India (Rajasthan, MadhyaPradesh,Chhattisgadh)
Rainwater harvesting is one of the surest ways of reducing our dependence on secondary sources of water like lakes or rivers. As there is a limted supply of water available to man, it is important that he learns to recycle and reuse water as well. This is where rainwater harvesting becomes important. The presentation that follows will allow a teacher to explain in simple terms what rainwater harvesting is, why it should be made popular, and how it is useful. Through this presentation children will also learn about some of the popular rainwater harvesting systems prevelant in the driest region of this country—Rajasthan, and surprisingly even the wettest—the Northeast. Why does a rain rich region like the Northeast need to harvest rainwater? Find out the answer to this and more through this PPT.
Lessons adoptable from ancient water management of Sri LankaDr. P.B.Dharmasena
The presentation discussed the objectives of ancient water management in Sri Lanka as:
1. Irrigation for food production
2. Human needs (settlement, drinking water, bathing, domestic needs etc.)
3. Rainwater harvesting systems
4. Environmental existence (flora, fauna etc.)
5. Building cities (Anuradhapura, Sigiriya etc.)
6. Urban planning
7. Basis for administrative boundaries
8. Mitigation of natural disasters (drought, flood, cyclone, epidemics etc.)
Managing tank cascades in the dry zone for Optimum supplyDr. P.B.Dharmasena
Presentation made at the seminar organized
by IEPSL on 19th August 2011 at Waters Edge, Colombo to explain the importance of tank cascade management in sustainable water resources management
This is the third lecture of the course 'Irrigation based Agro-ecosystems' conducted at the Faculty of Social Sciences and Humanities of the Rajarata University of Sri Lanka
Presentation made at the Discussion Forum on Cascade Development in NCP, NP and NWP held on 26th November 2013 at the Conference Room of the
Uma Oya Multipurpose Development Project, Ministry of Irrigation & Water Resources Management, No. 26, Jawatte Road, Colombo 5
The irrigation works in ancient Sri Lanka, the earliest dating from about 300 BCE, in the reign of King Pandukabhaya and under continuous development for the next thousand years, were some of the most complex irrigation systems of the ancient world.
The lecture contains aspects such as Ancient Water Resources Planning, Water shortage, or water wastage in Sri Lanka?, Network of tanks and streams in the form of cascades, Tank-village Ecosystem, Patial desilting concept
This is the 3rd lesson taught to students of B.A. (General) at the Faculty of Social Sciences and Humanities, Rajarata University of Sri Lanka, under the course; Water Resources Planning and Development
This is a presentation made to IESL members on 29th December 2019 at The Sigiriya Air Force premises.
Water resources management master plan in Sri Lanka includes not only irrigation but many more purposes.
This is the part 1 of 5th lesson in the course 'Traditional Knowledge in Sri Lankan Agriculture' taught at the Faculty of Agriculture, Rajarata University of Sri Lanka
Sustainable Water Management in Cascade System: A model in Environmentally Se...Dr. P.B.Dharmasena
Introduction
Origin of tank cascade concept
Tank cascade systems of Sri Lanka: Anatomy, distribution and definitions
Importance of cascade approach
Traditional tank-village ecosystem – adaptive capacity for present situation
Probing Unresolved Mysteries of Ancient Water TechnologyDr. P.B.Dharmasena
Presentation made at History & Heritage Forum, the Institution of Engineers, Sri Lanka on 15th September 2022.
Present crisis of water
Ancient master plan of water resources management
Water based city planning - Anuradhapura
Rainwater harvesting – Pidurangala
Tank cascade systems: The first agricultural heritage in Sri Lanka
Traditional tank-village ecosystem- Lessons for future ‘evergreen agro-ecosystems’ concept
Introduction
Origin of tank cascade concept
Tank cascade systems of Sri Lanka: Anatomy, distribution and definitions
Importance of cascade approach
Traditional tank-village ecosystem – adaptive capacity for the present situation
Cascade Tank Village System and identification of novel post graduate researc...Dr. P.B.Dharmasena
Seminar on Research collaboration opportunities with School of Environment and Rural Science, University of New England, Australia - 14th September 2018, NRMC, Peradeniya, Sri Lanka
The lecture delivered at the Post Graduate Institute of Humanities and Social sciences, University of Peradeniya, Peradeniya, Sri Lanka on 8th October 2017 with following content:
River basin-level planning; Network of tanks and streams; Cascade ecology; Tank-village ecosystem; Traditional Agricultural Practices in adaptation to drought; Rainwater harvesting from rock
The importance of maintaining the ecological balance in tank cascade systemsDr. P.B.Dharmasena
Presentation made at the Short Course on Tanks Rehabilitation and Cascade Development organized by Centre for Environmental Studies, University of Peradeniya, 26-27-January, 2019, Sri Lanka
Lesson Four - Indigenous Village Irrigation Systems, traditional small scale ...Dr. P.B.Dharmasena
This is the Guest Lecture 4 delivered for Agriculture students of the Faculty of Agriculture, Rajarata University of Sri Lanka.
It explains:
Globally Important Agricultural Heritage System
Ancient water resources management planning in Sri Lanka
Tank Cascade Systems of Sri Lanka
Tank-village Ecosystem
Traditional Vision of Water Management
Restoration of Village Irrigation Systems
What is an urban Lake? How do I engage with my local lake? How do we work together to protect and rejuvenate our urban lake? Using Bangalore's example, and building on the work by many urban lake groups, citizens and Biome Environmental Trust, here is an introduction to urban lakes and how we as citizens can engage with our common pool urban natural resources. For more information, contact water@biome-solutions.com.
Sri Lankan traditional knowledge in adaptation to climate changeDr. P.B.Dharmasena
Presentation made at the Workshop on “Conservation and Utilization of Local Varieties, Traditional Knowledge Associated with Genetic Resources and Agriculture”, held on 9th January 2017 at Oak Ray Regency Hotel, Kandy organized jointly by Department of Agriculture (DOA) Sri Lanka and the Ministry of Agriculture, Forestry and Fisheries (MAFF) Japan, Biodiversity for Adaptation to Climate Change (BACC) Project and Biodiversity for Food and Nutrition (BFN )Project, Department of Agriculture’
This is the part 2 of 5th lesson in the course 'Traditional Knowledge in Sri Lankan Agriculture' taught at the Faculty of Agriculture, Rajarata University of Sri Lanka
Similar to Ancient Water Resources Management in Sri Lanka (20)
This is a presentation made on Climate Smart Agriculture for training of trainers under the project on Building Resilience and Strengthening Community Disaster Preparedness in Sri Lanka
4 Climate Resilience WV English for training of trainersDr. P.B.Dharmasena
This is a presentation made for trainers on Climate Resilience
under the project on Building Resilience and Strengthening Community Disaster Preparedness in Sri Lanka
This is a TOT presentation made on Climate Change Mitigation and Adaptation Strategies for the project - Building Resilience and Strengthening Community Disaster Preparedness in Sri Lanka
2 Climate change on agriculture for training of trainersDr. P.B.Dharmasena
This is a TOT presentation on Agriculture and Climate Change
made for the project - Building Resilience and Strengthening Community Disaster Preparedness in Sri Lanka
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This is a presentation made for trainers on soil and climate under the project on Building Resilience and Strengthening Community Disaster Preparedness in Sri Lanka
Developing 2050 Carbon Net Zero Road Map & Strategic Plan for Sri Lanka - ...Dr. P.B.Dharmasena
This validation workshop was held after preparing the Road Map and Strategic Plan for Sri Lanka and the authors are responsible for the agriculture sector.
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Why cascade systems again?
Drought and flood events can be expected more due to climate change
High prevalence of poverty in tank cascade areas
Mal-nutrition can be greatly reduced by tank fishery and animal husbandry
Better land use under cascade principles – addresses ecological issues such as clearance of village forests, unsustainable land use etc.
Improve living conditions
Health issues ? – drinking water, contamination of agro-chemicals and heavy metals leads to kidney failures, malaria etc.
Most importantly It is an answer to drought hazards
A rainwater harvesting technology;
A soil moisture and groundwater maintaining technology;
A soil erosion and siltation control technology;
A technology that ensured the maintenance of ecological balance;
A technology that promotes social cohesion and needs for community leadership;
A system that accommodates spiritual development which promotes egalitarian (equally treated) attitudes especially during droughts;
A system that nurtured the development of drought insurance through animal husbandry
Main GHGs from agricultural lands are CH4 and N2O
GHG emission can be reduced by 60 % in 2050 through:
Removal of rice straws and through good management practices in paddy fields
Use alternatives to chemical fertilizer
CH4 reduction from livestock by improving feed quality and animal comfort
Reduce N2O emission in soils
Enhance C sequestration in paddy and rainfed uplands through ‘Evergreen Agro-ecosystem’ concept
Carbon stock in agricultural lands can be enhanced by improving land management practices
C sequestration in tea lands can be increased through: Agro-ecosystem approach; Crop diversification; Intercropping; Introduction of shade trees with optimum density; and Rehabilitation of old tea lands
C stock can be increased by 267 % by the year 2050 through Home Garden Intensification
If the proposed mitigation actions are implemented, the country will be able to achieve Net Zero by 2038.
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Part 2 - pilot demonstrations
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The Inception Report was finally accepted by the client on 19th July 2019 one month after the departure of the former Team Leader.
The progress has been seriously affected due to above reason
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All agricultural users will adopt rice agro-ecosystem practices'
through
Participatory technology demonstration, extension and training.
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1. Ancient Water Resources Management in Sri Lanka
P.B. Dharmasena, 0777-613234, 0717-613234
dharmasenapb@ymail.com, dharmasenapb@gmail.com
https://independent.academia.edu/PunchiBandageDharmasena
https://www.researchgate.net/profile/Punchi_Bandage_Dharmasena/contributions
http://www.slideshare.net/DharmasenaPb
2. CONTENT
• Multipurpose water management in ancient Sri Lanka
• Water management master plan
• Ancient water based city planning
• Shortage of water or wastage of water?
• Tank cascade systems: The first agricultural heritage in Sri Lanka
• Traditional tank-village ecosystem
• Ancient rainwater harvesting – Evidence from Pidurangala
3. Multipurpose water management in ancient Sri
Lanka
Water management was of multi-purpose:
• Food production – irrigation;
• Human needs – settlement, drinking water, bathing, recreation, other
domestic needs;
• Rainwater harvesting systems;
• Existence of the environment (flora, fauna, environs);
• City planning (Anuradhapura, Sigiriya)
• Parks, landscaping etc. (water springs, ponds)
• Administrative boundaries
• Natural disaster mitigation (Flood, drought, cyclone, epidemics)
4. Water Management Master Plan of Sri Lanka
Country level
Inter-river basin level
Inter-reservoir level
Sub-watershed level
Village level
Field level
8. Sharing water resources in the past
(600 BC – 1200 AD)
• Inter-river basin water
resources sharing
• Dambulu Oya -
Malwathu Oya
diversion canal (860
AD)
• Malwathu Oya -
Kanadara Oya
diversion canal (860
AD)
• Yoda Ela -
Nachchduwa feeder
canal (540 AD)
Mahakanadarawa
Nachchaduwa
Kalawewa-Balaluwewa
Dambulu oya
Malwathu oya
Kanadara oya
Kala Oya
9. Manewa cascade
Mahakanumulla cascade
• Single bank canal
• It runs along contour
• Water is collected from upstream
• Water is released to both sides
• Canal moves along tank upstream
• Tank cascade systems are fed
Kalawewa-Thisawewa Giant Canal
10. April – May 2010
“Inconvenient Truth” behind
Engineering Designs of
Irrigation Projects developed
during the Last Century.
“……….Those days we thought
that the canal was planned to
avoid rock barriers as the ancient
people did not own the
technology to break them
……..”
- Eng. Mahinda Panapitiya
11. • Inter-reservoir water
resources sharing
– Kalawewa -
Thisawewa Yodha Ela
(470 AD)
– Nachchaduwa -
Nuwarawewa feeder
canal (290 AD)
– Balaluwewa -
Siyambalangamuwa
feeder canal (290 AD)
– Basawakkulama -
Maha Vilachchiya
feeder canal (470 AD)
Kalawewa-Balaluwewa
Thisawewa
Siyambalangamuwa
Nachchaduwa
Nuwarawewa
Mahavilachchiya
Basawakkulama
Malwathu oya
Thalawa oya
Kala oya
Sharing water resources in the past
(600 BC – 1200 AD)
12. It could be the city plan of
Ancient Anuradhapura kingdom
Mystery of Star gate
15. Water culture in Anuradhapura Kingdom
• Water cordon around the kingdom (Thisawewa, Nuwarawewa,
Basawakkulama, Bulankulama)
• Focused to enrich groundwater in the kingdom
• Paddy lands under these tanks are relatively low
• Catchments are not adequate
• Tanks are fed by an adjoining river basin
• Alluvial soil is found due to Malwathuoya and Halpanoya
• How these gigantic structures could be sustained?
• Hard bedrock to trap groundwater (granitic gneiss සහ charnockite
gneiss)
18. Ponds, water cordons, water tunnels and wells are scattered in the
kingdom to replenish and monitor groundwater
19. Cities being sunk due to depletion of groundwater table
1. Beijing in China by 11
cm/ year
2. Mexico by 28 cm/ year
3. Jakarta by 28 cm/ year
4. Bangkok by 12 cm/ year
1
2
3
4
20. Annual average rainfall: 2,000 mm
Land extent: 65,610 km2
Total volume of water: 131.22 bil. m3
Discharge to sea: 66.18 bil. M3 (>50%)
No. of river basins: 103
Major reservoirs and dams: 80
Small tanks: 14204
Small anicuts: 12,942
Source: N. Eriyagama et al 2015
Shortage of water or wastage of water?
21.
22. River basins – Water losses to Sea
River Basin Total Basin
Area (km2)
River
lengths
(km)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Deduru Oya 2,616 142 4,794 1,608 34.0
Kala Oya 2,772 148 4,424 587 13.0
Malwathu Oya 3,246 164 4,592 568 12.0
Yan Oya 1,520 142 2,269 300 19.0
Kelani Ganga 2,278 145 8,692 5,474 62.0
Gin Ganga 922 113 3039 1903 62.0
Kalu Ganga 2,688 129 10,122 7,862 77.0
Walawe Ganga 2,442 138 9,843 2,165 22.0
Mahaweli Ganga 10,327 335 26,804 11,016 41.0
Meeoya 1,516 109 2,176 338 16
Shortage of water or wastage of water?
23. River Basin Total Basin
Area (km2)
River
lengths (km)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Kalu Ganga 2,688 129 10,122 7,862 77.0
Source: Dept. of Agrarian
Development
Major reservoirs: 0
Minor tanks: 3
24. River Basin Total Basin
Area (km2)
River
lengths (km)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Kelani Ganga 2,278 145 8,692 5,474 62.0
Source: Dept. of Agrarian
Development
Major reservoirs: 2
Minor tanks: 9
25. River Basin Total Basin
Area (Km2)
River
lengths
(km)
Total Rainfall
(million M3)
Drainage to Sea
(million M3) %
Gin Ganga 922 113 3039 1903 62.0
Source: Dept. of Agrarian
Development
Major reservoirs: 0
Minor tanks: 0
26. River Basin Total Basin
Area (km2)
River
lengths
(km)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Deduru Oya 2,616 142 4,794 1,608 34.0
Major reservoirs: 4
Minor tanks: 2408
Source: Dept. of Agrarian
Development
27. River Basin Total Basin
Area (km2)
River
lengths
(km)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Malwathu Oya 3,246 164 4,592 568 12.0
Major tanks: 05
Minor tanks: 1731
Source: Dept. of Agrarian
Development
28. River Basin Total Basin
Area (km2)
River
lengths
(km)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Walawe Ganga 2,442 138 9,843 2,165 22.0
Source: Dept. of Agrarian
Development
Major/ medium reservoirs: 12
Minor tanks: 750
29. River Basin Total Basin
Area (km2)
River
lengths
(km)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Kala Oya 2,772 148 4,424 587 13.0
Major reservoirs: 3
Minor tanks: 1015
Source: Dept. of Agrarian
Development
30. River Basin Total Basin
Area (km2)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Yan Oya 1,520 2,269 300 19.0
Major tanks 2
Small tanks 746
31. Source: Dept. of Agrarian Development
River Basin Total Basin
Area (km2)
Total Rainfall
(million m3)
Drainage to Sea
(million m3) %
Mee Oya 1,516 2,176 338 16.0
Major tanks 1
Small tanks 750
34. Tank clusters or cascades
Hydrology based definition
• A ‘cascade’ is a connected series of tanks organized within a micro-catchment (meso
catchment) of the dry zone landscape, storing, conveying and utilizing water from an
ephemeral rivulet’. – Madduma Bandara, 1985
Ecology based definition
• Tank cascade is an ecosystem,
where water and land resources
are organized within the micro-
catchments of the dry zone
landscape, providing basic needs
to human, floral and faunal
communities through water, soil,
air and vegetation with human
intervention on sustainable basis’.
– Dharmasena, 2017
35. Distribution of tank
cascades in Sri Lanka
Main factors:
1. Morphology (landscape)
• Lower elevation,
• Moderate undulation
2. Rainfall
• Bimodality
• ~1500 mm/ year
3. Soil and geology
• Regolith aquifers
• Low infiltration
• RBE – LHG
38. Sanitary places of
women and kids
Sanitary places of men
Faeces as a nutrient source to paddy fields
Tank-village system has been declared now as a
Globally Important Agriculture Heritage System (GIAHS) by UN
A Self sustained System based on precise management of water
41. Therefore, I suggest it is essential to probe deeply the awakening of ‘Sri Lankan Water Culture’
not only through a physical/ engineering point of view but also on the basis of a spiritual
dimension.
When we attempt to study the creations made by a human society nurtured in a spiritual environs
by using only physical and environmental principles we may understand only a fraction of it.
64. Finally ……….
The platform area of Pidurangala rock is about 2 ha. If it is
assumed that 80% of monthly rainfall could be collected from
this flow pitch, the volume, which could be stored monthly is:
Months Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Total
Rainfall
(mm) at
75%
probability
30.3 12.6 26.0 87.7 31.8 3.1 3.4 4.4 25.9 132.0 168.3 105.7 631.2
Runoff (m3) 485 202 416 1,403 509 50 54 70 414 2,112 2,693 1,691 10,099
65. • According calculations at least 10,000 m3 of water can be
collected from this system.
• What does it mean?
• This historical perception can be rejected as a myth.
• However, this system if rehabilitated will supply annual
water storage of 10,000 m3 to the people, who are living
around and are threatened with the chronic renal disease
with unknown aetiology.
Then …..
66. • If the daily drinking water requirement is 3
lits./head, the problem of annual drinking
water requirement of 9,000 people can easily
be solved