- 1. Integrated Watershed Management & Rainwater Harvesting
Prof. T. I. Eldho ,Department of Civil Engineering,Indian Institute
of Technology Bombay/ India.
- Watershed Development & Modelling
- Integrated Watershed Management
- Water Conservation & Harvesting
2. Integrated Water Resources Development and Management:
IWRDM.Integration of - - River basin resources- surface and ground.
- Demands - consumptive and non-consumptive, and supplies.-
Facilities - mega to micro. -Human and eco-systems. - S&T and
engineering with social, economic, synergic needs. 3.
- INDIAS LAND RESOURCE, IRRIGATION
- India has 2% of worlds land, 4% of freshwater, 16% of
population, and 10% of its cattle.
- Geographical area = 329 Mha of which 47% (142 Mha) is
cultivated, 23% forested, 7% under non-agri use, 23% waste.
- Per capita availability of land 50 years ago was 0.9 ha, could
be only 0. 14 ha in 2050.
- Out of cultivated area, 37% is irrigated which produces 55%
food; 63% is rain-fed producing 45% of 200 M t of food.
- In 50 years (ultimate), proportion could be 50:50 producing
75:25 of 500 M t of required food.
4.
- SOME INFERENCES FROM RIVER BASIN STATISTICS
- Himalayan Rivers Water: 300 utilizable, 1200 BCM
available.
- Himalayan large dams presently store 80 BCM. New dams under
consideration could store 90 BCM.
- Peninsular Rivers Water: 400 utilizable, 700 BCM
available.
- Peninsular large dams presently store 160 BCM.New dams under
consideration could store 45 BCM.
- In all, large dams presently store 240 BCM.New dams under
consideration could store 135 BCM.Total storage thus could be 375
BCM only.
5.
- WITHDRAWAL OF WATER- 2050, AVAILABILITY
- Indias Yearly Requirement in 2050 (Km 3= BCM)
- For growing food and feed at 420 to 500 million tonnes = 628 to
807 BCM
- Drinking water plus domestic and municipal use for rural
population at 150 lpcd and for urban population at 220 lpcd = 90 to
110 BCM
- Hydropower and other energy generation = 63 to 70 BCM
- Industrial use = 81 to 103 BCM
- Navigational use = 15 BCM
- Loss of water by evaporation from reservoirs = 76 BCM
- Environment and ecology = 20 BCM
- Availability 1100 to 1400 BCM
6.
- Where does the water come from?
- New dams -inter-basin transfer
- Groundwater - underdeveloped
- Water savings - increase in efficiency, reduce
evaporation.
- Water productivity - increases in crop per drop
- Trade (virtual water), import food.
7. Part 2: Watershed Development & Modelling
- L imited water resources,-
- Watershed is the basic scientific unit.
- Need for proper planning and management.
- Integrated watershed development approach
- Recent advances in watershed modelling -use ofcomputer models,
remote sensingand GIS.
8. WATERSHED Development
- Watershed Characteristics.
Watershed Sub-watershed Milli- watershed Micro-watershed
Mini-watershed 50,000-2,00,000 10,000-50,000 1,000-10,000 100-1,000
10-100 Classification Watershed (ha) 9. WATERSHED Development
10. WATERSHED MODELLING Watershed modellingsteps 1. Formulation
2. Calibration/verification3. ApplicationWatershed model
constitutes 1. Input function 2. Output function3. Transform
function 11. FigFlowchart of simple watershed model (McCuen, 1989)
WATERSHED MODELLING Precipitation Interception Storage Surface
Runoff Groundwater Storage Channel Processes Interflow Direct
Runoff Surface Storage Baseflow Percolation Infiltration ET ET 12.
WATERSHED MODELLING General Classification of Models Broadly
classified into three types Black Box Models: These models describe
mathematically the relation between rainfall and surface runoff
without describing the physical process by which they are
related.e.g. Unit Hydrograph approach Lumped models: These models
occupy an intermediate position between the distributed models and
Black Box Models.e.g. Stanford Watershed ModelDistributed Models:
These models are based on complex physical theory, i.e. based on
the solution of unsteady flow equations. 13. Background
- Large water resources development projects in India
- haveadverse socio-economic and environmental consequences
.
- The failure of such projects, contributed toindebtedness ,
- raisingeconomic pressureand jeopardising future
development.
- Indiscriminateexpansion of marginal
landsandover-utilisation
- of existing water resourcesfor irrigation.
- Traditionalwater harvesting systemshave suffered sever
neglect.
- This type of development not only called into question
- theadequacy of water resources schemesbut triggered the
urgent
- search for moreeffective and appropriate management strategies
.
- Major response to follow Integrated Watershed Management
Approach .
Part 3:Integrated Watershed Management 14. Concepts and
Principles of IWM Objectives: Water hasmultiples usesand must be
managed in an integrated way. Water should be managed at thelowest
appropriate level . Water allocation should takeaccount of the
interests of allwho are affected. Water should be recognised and
treated as an economic good. Strategies: A long term,
viablesustainable futurefor basin stake holders. Equitable access
to water resources for water users. The application ofprinciples of
demand managementfor efficient utilisation. Prevention of
furtherenvironmental degradation(short term) and the restoration
ofdegraded resources (long term). . Implementation Programs:
Comprise an overall strategy that clearly defines the management
objectives, a delivery mechanisms and amonitoring schedulethat
evaluatesprogram performance . Recognise that the development of
water resources may require research, to assess theresource base
throughmodelling and development of DSS , and to determine
thelinkage between water resources and theimpacts on environment,
socio-economy . Ensure that mechanisms and policies are established
that enables long term support. 15. Integrated Watershed Approach
IWM is the process of planning and implementing water and natural
resources an emphasis on integrating the bio-physical,
socio-economic and institutional aspects.Social issues are
addressed throughinvolvement of women and minority .Community
ledwater users groupshave led the implementation efforts.1970 1980
1990 2000 Public Participation Watershed development program Low
High Mainly waterconservation Socio-economic withwater conservation
Socio-economic,water conservation, participation Public
participationplanning, design,implementation Project success
16.
- The four engineering and management tools for effective and
sustainable development of water resources in semi-arid rural India
: -
-
-
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- Decentralised development system
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-
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- Catchment based water resources planning
-
-
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- Management information system
- In past the efforts were more on the soil conservation and
taking measures on the land where as we used to neglect the welfare
of the land users.
- F or sustainable watershed managementthere is need to integrate
the social and economic development together with soil and water
conservation
17. IWA Modeling through Advanced Technologies 18. Part 4: Water
Conservation & Harvesting Total water management for
sustainable development ?. 19. Water Conservation
- Important step for solutions to issues of water and
environmental conservation is to change people's attitudes and
habits
- Conserve water because it is right thing to do!.
- What you can do to conserve water ?
- Use only as much water as you require. Close the taps well
after use. While brushing or other use, do not leave the tap
running, open it only when you require it. See that there are no
leaking taps.
- Use a washing machine that does not consume too much water. Do
not leave the taps running while washing dishes and clothes.
20. Water Conservation
- Install small shower heads to reduce the flow of the water.
Water in which the vegetables & fruits have been washed - use
to water the flowers & plants.
- At the end of the day if you have water left in your water
bottle do not throw it away, pour it over some plants.
- Re-use water as much as possible
- Change in attitude & habits for water conservation
21. Rain Water Harvesting?.
- Rain Water Harvesting RWH- process of collecting, conveying
& storing water from rainfall in an area for beneficial
use.
- Storage in tanks, reservoirs, underground storage-
groundwater
22. Rain Water Harvesting?.
- RWH - yield copious amounts of water. For an average rainfall
of 1,000mm, approximately four million litres of rainwater can be
collected in a year in an acre of land (4,047 m 2 ),
post-evaporation.
- A s RWH - neither energy-intensive nor labour-intensive
- It can be a cost-effective alternative to other water-accruing
methods.
- With the water table falling rapidly, & concrete surfaces
and landfill dumps taking the place of water bodies, RWH is the
most reliable solution for augmenting groundwater level to attain
self-sufficiency
23.
- Roof Rain Water Harvesting
- Land based Rain Water Harvesting
- Watershed based Rain Water harvesting
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- For Urban & Industrial Environment
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-
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- Public, Private, Office & Industrial buildings
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-
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- Pavements, Lawns, Gardens & other openspaces
RWH Methodologies 24. Rain Water Harvesting Advantages1.Provides
self-sufficiency to water supply2.Reduces the cost for pumping of
ground water 3.Provides high quality water, soft and low in
minerals 4.Improves the quality of ground water through dilution
when recharged 5.Reduces soil erosion & flooding in urban areas
6.The rooftop rain water harvesting is less expensive &easy to
construct, operate and maintain 7. In desert, RWH only relief8.I n
saline or coastal areas & Islands, rain water provides good
quality water 25. Part 5: Successful Case Study Catchment Area =
1800 km 2 26. Jhabua Watershed: Case Study
-
- Madhya Pradesh ( INDIA ),~ altitude of 380 m to 540 m. Area
1800 sq.km
Highly undulating, sparsely distributed forest cover.~ 57%
arable land including cultivable fellow and~ 18% notified as forest
land. Average rainfall~ 750 mm per annum.~ 20-30 events during
June-September ~ Classified as drought prone region. Moisture
deficitduring Januaryto May months each year. 27. Jhabua watershed:
Case study Major crops:Maize, Cotton, Peanuts, Soyabeans; Gram,
Black beans, Oil seeds.Predominantly tribal population, 92% engaged
in agriculture. ~high seasonal migration ~ economically one of
themost backward district 28. Yearly rainfall departure from the
mean for rainfall station Jhabua Seasonal rainfall departure are
extremely variable. 29.
- Subsistence of rain-fed mono-cropping farming system with low
agriculture productivity
- Undulating topography and soil erosion due to overgrazing
causing degradation of land.
- High pressure of population on the agriculture land leading to
substantial poverty causing immigration.
- Absence of decentralized water resources and basic
infrastructure facilities.
- Degradation of forestry land due to absence of community
involvement in protection of the forest.
Development Issues 30. Planning & Implementation
- AThree step IWMA model approach
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- Resources Mapping using Geographical Information System
-
- Management Information System
31. Resources mapping: Ground water dynamics Total alluvium
area= 18.5 km 2 Channel porosity = 20% Depth of wetting front = 4.0
m Total storage capacity = 14.8 x10 6m 3. 32. Resources mapping:
Surface water storage Total number of reservoirs = 144 Storage
capacity = 81.3 x 10 6m 3 Reservoir in main channel 33. Appropriate
Technology Water conservation and groundwater recharge techniques
Water harvesting cum supplementary irrigation techniques in Jhabua
34. Water Conservation Water conservation interventions includes
contour trenches,gully plugging, vegetative and field bunding,
percolation tanks.Overall land treatment against potential area is
varying between 40-60%.Type of land ownership for soil and water
conservation measuresTechniques of soil and water conservation
measures 35. Redevelopment of forest is essential for catering
socio- economics needs of the people and ecological needsof the
region.Forest committeesare formed for forest protection and part
of area is made available for grazing on rotation
basis.Implementing agencies promoted the concept ofSocial
Fencingpeople protecting the forest and grazing land.Joint Forest
Management 36. Community participation and local capacity building
Development of new village level institutions and local capacity
building.Operation & maintenance of structures, regulation of
financial matters, and conflict resolution. 37. Discussion Success
interventions reside inintegration of appropriate technical and
managerial measures .Peoples participation in the entire process
are most important.The benefits of water harvesting and water
conservation definitely reached.Efficient utilisation of funds ,
only 10-15% spent on non-project costs.Limitation:100% drought
proofing for every water use can not be achieved.Thus,IWM
approachmay be characterised by
- Community management built onexisting social structure ,
- Project management drawn fromvillage level organisations ,
- Joint forest management withcommunity participation ,
- Self-help water user groups and community based banking
institutions.
38. Concluding Remarks The integrated watershed management
approachhave the following major components:
- Promotesustainable economic developmentthrough optimum
- utilisation of natural resources and local capacity
building.
- Restoreecological balancethrough community participation
- and cost affordable technologies for easy acceptance.
- Improvingliving conditionsof the poorer through more
equitable
- resources distribution and greater access to income
39. Concluding Remarks
- Water security through IWM
- Efficient utilisation of fundsas only 10-15% of the total
budget
- spent on non-project costs.
- The benefits of water harvesting and water conservation not
only for
- drinking water security but also for agriculture definitely
reached.
- About 2-4 meter water level increase is observed in selected
wells.
- Watershed management can easily cope withclimate change impacts
.
40. Dr. T. I. Eldho Associate Professor, Department of Civil
Engineering,Indian Institute of Technology Bombay, Mumbai, India,
400 076.Email:[email_address] Phone: (022) 25767339; Fax: 25767302
http://www. civil.iitb.ac.in