Watershed Planning

1. Integrated Watershed Management
& Rainwater Harvesting
Prof. T. I. Eldho , Department of Civil Engineering,
Indian Institute of Technology Bombay/ India.
•Contents
• India’s Water Resources
• Watershed Development & Modelling
• Integrated Watershed Management
• Water Conservation & Harvesting
• Successful Case Study

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. INDIA’S LAND RESOURCE, IRRIGATION
AND FOOD PRODUCTION
• India has 2% of world’s 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
India’s Yearly Requirement in 2050 (Km3 = 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
Total 970 to 1200 BCM
Availability 1100 to 1400 BCM

6. Where does the water come from?
•New dams - inter-basin transfer
•Groundwater - underdeveloped
•Demand Management
•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
Limited water resources,-
more demand.
Watershed is the basic scientific unit.
Need for proper planning and management.
Integrated watershed development approach
Digital revolution
Recent advances in watershed modelling -
use of computer models, remote sensing
and GIS.

8. WATERSHED Development
Watershed
Characteristics.
Hydrology of
watershed.
Watershed (ha) Classification
50,000-2,00,000
10,000-50,000
1,000-10,000
100-1,000
10-100
Watershed
Sub-watershed
Milli- watershed
Micro-watershed
Mini-watershed

9. WATERSHED Development …
Parameters of Watershed
• Size
•Shape
•Physiography
•Climate
•Drainage
•Land use
•Vegetation
•Geology and Soils
•Hydrology
•Hydrogeology
•Socioeconomics

10. WATERSHED MODELLING …
Watershed modelling steps
1. Formulation
2. Calibration/verification
3. Application
Watershed model constitutes
1. Input function
2. Output function
3. Transform function

11. Precipitation
Interception
Storage
Surface Runoff
Groundwater
Storage
Channel
Processes
Interflow
Direct Runoff
Surface Storage
Baseflow
Percolation
Infiltration
ET
ET
Fig Flowchart of simple watershed model (McCuen, 1989)
WATERSHED MODELLING …

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 Model
Distributed 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
have adverse socio-economic and environmental consequences.
• The failure of such projects, contributed to indebtedness,
raising economic pressure and jeopardising future development.
• Indiscriminate expansion of marginal lands and over-utilisation
of existing water resources for irrigation.
• Traditional water harvesting systems have suffered sever neglect.
• This type of development not only called into question
• the adequacy of water resources schemes but triggered the urgent
• search for more effective 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 has multiples uses and must be managed in an integrated way.
 Water should be managed at the lowest appropriate level.
 Water allocation should take account of the interests of all who are affected.
 Water should be recognised and treated as an economic good.
Strategies:
 A long term, viable sustainable future for basin stake holders.
 Equitable access to water resources for water users.
 The application of principles of demand management for efficient utilisation.
 Prevention of further environmental degradation (short term) and the restoration of
degraded resources (long term). .
Implementation Programs:
 Comprise an overall strategy that clearly defines the management objectives, a delivery
mechanisms and a monitoring schedule that evaluates program performance.
 Recognise that the development of water resources may require research, to assess the
resource base through modelling and development of DSS, and to determine the
linkage between water resources and the impacts 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 through involvement of women and minority.
Community led water users groups have led the implementation efforts.
1970 1980 1990 2000
Public
Participation
Watershed development program
Low
High
Mainly
water
conservation
Socio-economic
with
water
conservation
Socio-economic,
water
conservation,
participation
Public
participation
planning,
design,
implementation
Project success

16. •The four engineering and management tools for effective
and sustainable development of water resources in semi-arid
rural India: -
• Appropriate technologies
• Decentralised development system
• Catchment based water resources planning
• 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.
• For sustainable watershed management there 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
Every drop counts!!!

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
• Hydrological Cycle

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 m2), post-evaporation.
•As 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
• For Urban & Industrial Environment –
• Roof & Land based RWH
• Public, Private, Office & Industrial buildings
• Pavements, Lawns, Gardens & other open
spaces
RWH – Methodologies

24. Rain Water Harvesting– Advantages
1.Provides self-sufficiency to water supply
2.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 relief
8. In saline or coastal areas & Islands, rain water
provides good quality water

25. Part 5: Successful Case Study
Catchment Area =
1800 km2

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 deficit during January
to 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 the
most 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
A Three step IWMA model approach
1. Resources Mapping using Geographical
Information System
2. Appropriate Technology
3. Management Information System

31. Resources mapping: Ground water dynamics
Total alluvium area= 18.5 km2
 Channel porosity = 20%
 Depth of wetting front = 4.0 m
Total storage capacity = 14.8 x106 m3.

32. Resources mapping: Surface water storage
Reservoir
in
main
channel
Total number of reservoirs = 144
Storage capacity = 81.3 x 106 m3

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%.
45%
30%
25%
Private land Fallow land Forest land
28%
65%
2% 5%
Contour bunding Gully plugging
Staggered trenching Level terraces
Type of land ownership for soil
and water conservation
measures
Techniques of soil and water
conservation measures

35. Redevelopment of forest is essential for catering socio-
economics needs of the people and ecological needs
of the region.
Forest committees are formed for forest protection and
part of area is made available for grazing on rotation
basis.
Implementing agencies promoted the concept of “Social
Fencing” people 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 in integration of appropriate technical and
managerial measures.
People’s 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 approach may be characterised by
•Community management built on existing social structure,
•Project management drawn from village level organisations,
•Joint forest management with community participation,
•Self-help water user groups and community based banking institutions.

38. Concluding Remarks
The integrated watershed management approach
have the following major components:
• Promote sustainable economic development through optimum
utilisation of natural resources and local capacity building.
• Restore ecological balance through community participation
and cost affordable technologies for easy acceptance.
• Improving living conditions of the poorer through more equitable
resources distribution and greater access to income
generating activities.

39. Concluding Remarks
• Water security through IWM
•Efficient utilisation of funds as 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 with climate change impacts.

40. Dr. T. I. Eldho
Associate Professor,
Department of Civil Engineering,
Indian Institute of Technology Bombay,
Mumbai, India, 400 076.
Email: eldho@iitb.ac.in
Phone: (022) – 25767339; Fax: 25767302
http://www.civil.iitb.ac.in