1. Rain Water Harvesting and Conservation of Water Resources 14th Sep. ‘10 Dr. N. Sai Bhaskar Reddy CEO, GEO saibhaskarnakka@gmail.com http://e-geo.org Centre for Cultural Resources and Training Ministry of Culture Govt. of India
6. RECHARGE WELLS While it would normally take between 20-30 years for water to percolate 100 feet from an open tank, it has been noticed in an open well 300,000 litres can percolate to the same depth within a week. The Barefoot College, Tilonia
9. Geographical area = 329 Mha of which 47% (142 Mha) is cultivated, 23% forested, 7% under non-agri use, 23% waste.
10. Per capita availability of land 50 years ago was 0.9 ha, could be only 0. 14 ha in 2050.uk-energy-saving.com
11. 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.
13. What Is Rainwater Harvesting? RWH technology consists of simple systems to collect, convey, and store rainwater. Rainwater capture is accomplished primarily from roof-top, surface runoff, and other surfaces. RWH either captures stored rainwater for direct use (irrigation, production, washing, drinking water, etc.) or is recharged into the local ground water and is call artificial recharge. In many cases, RWH systems are used in conjunction with Aquifer Storage and Recovery (ASR). ASR is the introduction of RWH collected rainwater to the groundwater / aquifer through various structures in excess of what would naturally infiltrate then recovered for use .ppt (11)
14. Why Rainwater Harvesting? Conserve and supplement existing water resources Available for capture and storage in most global locations Potentially provide improved quality of water Supply water at one of the lowest costs possible for a supplemental supply source. Capturing and directing storm water (run-off) and beneficially use it Commitment as a corporate citizen - showcasing environmental concerns Public Mandate (India) Replenishing local ground water aquifers where lowering of water tables has occured .ppt (12)
15. Why Not RWH? Not applicable in all climate conditions over the world Performance seriously affected by climate fluctuations that sometimes are hard to predict Increasingly sophisticated RWH systems (ASR) necessarily increases complexities in cost, design, operation, maintenance, size and regulatory permitting Collected rainwater can be degraded with the inclusion of storm water runoff Collected water quality might be affected by external factors Collection systems require monitoring and continuous maintenance and improvement to maintain desired water quality characteristics for water end-use Certain areas will have high initial capital cost .ppt (13)
16. .ppt (14) Condensation Let’s take a look at The Water Cycle Precipitation Evapotranspiration Evaporation Infiltration Surface Runoff Surface Water Consumption Groundwater Sea water intrusion
18. .ppt (16) Collection Area and Characteristics Measure Area Runoff Characteristics Roof top 0.75 – 0.95 Paved area 0.50 – 0.85 Bare ground 0.10 – 0.20 “Green area” 0.05 – 0.10 Water harvesting potential(m3) = Area (m2) X Rainfall (m) X Collection Efficiency
19. .ppt (17) Quality Issues Roofs contain: bird droppings, atmospheric dust, industrial and urban air pollution
20. .ppt (18) Operational Procedures and Design Considerations
21. .ppt (19) Operational Procedures and Design Considerations
22. A news article says that ground water levels in New Delhi are falling and RWH will become mandatory. .ppt (20)
23. Storage Ponds and Reservoirs Artificial recharge of Groundwater Water Tanks Rainwater runoff in surface water Rainwater runoff in groundwater Rainwater runoff in tanks Effluent in surface water Effluent in ground water Every drop counts
31. WATERSHED MODELLING … Precipitation ET Interception Storage ET Surface Runoff Surface Storage Infiltration Interflow Direct Runoff Percolation Baseflow Groundwater Storage Channel Processes Flowchart of simple watershed model (McCuen, 1989)
32. High Project success Socio-economic, water conservation, participation Socio-economic with water conservation Public participation planning, design, implementation Public Participation Mainly water conservation Low 1970 1980 1990 2000 Watershed development program 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. Prof. T. I. Eldho ,
33. Water Conservation & Harvesting Total water management for sustainable development?. Prof. T. I. Eldho ,
36. 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 measures Techniques of soil and water conservation measures Prof. T. I. Eldho ,