rainwater harvesting walamtari june12_1
TRANSCRIPT
Rain Water Harvesting
5.6.2012
Dr. N. Sai Bhaskar ReddyCEO, GEOhttp://e-geo.org
Workshop for Rain water Harvesting campaign with United Federation of Resident Welfare Associations (U-FERWAS)
Water and Land Management Training and Research Institute (WALAMTARI), Govt. of AP
Climate Change and drought
2
Meteorological DroughtMeteorological drought is the amount of dryness and the duration of the dry period. Atmospheric conditions that result in deficiencies of precipitation change from area to area.
Hydrological Drought Hydrological drought is associated with the effects of periods of precipitation shortages on water supply. Water in hydrologic storage systems such as reservoirs and rivers are often used for multiple purposes such as flood control, irrigation, recreation, navigation, hydropower, and wildlife habitat. Competition for water in these storage systems escalates during drought and conflicts between water users increase significantly.
Agricultural DroughtAgricultural drought mainly effects food production and farming. Agricultural drought and precipitation shortages bring soil water deficits, reduced ground water or reservoir levels, and so on. Deficient topsoil moisture at planting may stop germination, leading to low plant populations.
Socioeconomic Drought Socioeconomic drought occurs when the demand for an economic good exceeds supply as a result of a weather-related shortfall in water supply. The supply of many economic goods, such as water, forage, food grains, fish, and hydroelectric power, depends on weather. Due to variability of climate, water supply is sufficient in some years but not satisfactory to meet human and environmental needs in other years. The demand for economic goods is increasing as a result of increasing population. Supply may also increase because of improved production efficiency and technology.
The Barefoot College, Tilonia
STRUGGLE FOR WATER
Water sharing – strategies for survival-Community borewells-Apartments / complexes-Street borewells
The Barefoot College, Tilonia
The Barefoot College, Tilonia
POLLUTED WATER
Every drop counts
uk-energy-saving.com
• 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.
INDIA’S LAND RESOURCE, IRRIGATION AND FOOD
PRODUCTION
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.
Freshwater management in India
Anupma Sharma
Water Conservation
Watershed management
Water quality conservation
Inter basin water transfer
GW management
Recycle and reuse of water
Public involvement and capacity building
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
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
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
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Condensation
Precipitation
Evaporation
Surface Water
Infiltration
Evapotranspiration
Let’s take a look atThe Water
Cycle
Consumption
Surface Runoff
Groundwater
Sea water intrusion
Design and Feasibility Criteria
Collection Area
Rainfall
Demand
Primary Use (Direct Use, Artificial Recharge (AR) or Aquifer Storage and Recovery (ASR))
Storage capacity
Level of Security - risk of the storage tank running dry
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
Quality Issues
Roofs contain: bird droppings, atmospheric dust,
industrial and urban air pollution
Operational Procedures and Design Considerations
Screen to prevent birds,
animal and insects;
Lead based paint must not be used on the
roof;
Tar based roof coatings and materials should
not be used – Phenolics and other organics can leach from materials
If roofs painted with acrylic paints, new concrete or metal roofing - first few rainfalls should not be
collected to avoid metals, detergents, and other
chemicals
GRAVEL AND SAND
CHARCOAL
SAND
GEO WATER FILTER
THREE 15 LITER TIN CANS, SAND, GRAVEL , TAP AND PVC PIPE
Operational Procedures and Design Considerations
Storage tank – dark materials to exclude light and algae formation
Corrosion resistant materials
Tank in protected shaded area –
lower temperature
For multiple storage tanks –
design for frequent turnover
Storage
1. Ponds and Reservoirs
2. Artificial recharge of Groundwater
3. Water Tanks
4. Rainwater runoff in surface water
5. Rainwater runoff in groundwater
6. Rainwater runoff in tanks
7. Effluent in surface water
8. Effluent in ground water
Every drop counts
Every drop counts
Every drop counts
Every drop counts
Jn nurm – URBAN RAIN WATER HARVESTING
Tackle water shortage during summers
Recharge aquifers
Reduced power consumption in pumping water
Reduced water logging and flooding in low lying areas
Reduced erosion
Improved Groundwater quality through dilution. Eg: Coastal areas
Means of water conservationNew dams - inter-basin
transfer
Groundwater - underdevelope
d
Demand Management
Water savings - increase in
efficiency, reduce evaporation.
Water productivity - increases in crop per drop
Virtual water – Food
production
Water Conservation…
Prof. T. I. Eldho , Prof. T. I. Eldho ,
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!
!!
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 pluggingStaggered trenching Level terraces
Type of land ownership for soil and water conservation
measures
Techniques of soil and water conservation measures Prof. T. I. Eldho , Prof. T. I. Eldho ,
Borewell recharge filters
Roof top rainwater harvestingAt AVANI, Berinag, Uttarakhand
RECHARGE WELLS
The Barefoot College, Tilonia
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.
THANK YOU