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Presentation made at Dr. Reddy Labs, Miyapur, Hyderabad on 25th January 2013
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Rainwater Harvesting
Dr. N. Sai Bhaskar ReddyCEO, GEO , http://e-geo.orgDr. Reddy Labs Miyapur, Hyderabad 25th
Janu
ary
2013
.ppt (2)
Condensation
Precipitation
Evaporation
Surface Water
Infiltration
Evapotranspiration
Let’s take a look atThe Water
Cycle
Consumption
Surface Runoff
Groundwater
Sea water intrusion
• Rainwater harvesting is the accumulating and storing of rainwater for reuse before it reaches the aquifer.
• The principle of collecting and using precipitation from a catchments surface.
The Barefoot College, Tilonia
The Barefoot College, Tilonia
POLLUTED WATER
Every drop counts
Freshwater management in India
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
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
Clean the gutters and tank every 3 months
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
Regional wind direction and industrial activity –
Lead, Mercury, other heavy metals
GRAVEL AND SAND
CHARCOAL
SAND
GEO WATER FILTER
THREE 15 LITER TIN CANS, SAND, GRAVEL , TAP AND PVC PIPE
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
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 conservation
New dams - inter-basin
transfer
Groundwater - underdeveloped
Demand Management
Water savings - increase in
efficiency, reduce evaporation.
Water productivity - increases in crop per drop
Virtual water – Food production
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!!!
Hyderabad RWH POTENTIAL
The annual average rainfall in Hyderabad is about 700mm per year, the MCH area is about 170 square kilometers. The amount of rainfall every year on Hyderabad’s MCH area is 118000 Mega Liters per Year (MLY) which is equivalent to 32300 Mega Liter per Day (MLD). The overall installed supply capacities of all reservoirs are 930 MLD. So the amount of rain fall in Hyderabad is more than thirty times the amount the city gets supplied with from the reservoirs. And this is just the rain falling in the MCH area which is less than 20 % of the GHMC area. The question is what happens with these clean, unpolluted water masses falling every year in Hyderabad.
Hyderabad
Hyderabad (Andhra Pradesh)Rainwater harvesting has been made mandatory in all new buildings with an
area of 300 sq m or more.
Tentative for enforcing this deadline was June 2001.• Mandatory to provide RWH in all Group Housing and Commercial
Complexes• Mandatory for all categories of buildings including residential• All existing buildings in Municipalities/Municipal Corporations shall
construct rain water harvesting structures within a period of one year from issue of this GO. Competent authority shall insist on implementation of RWH in all layouts and sub divisions for sanctioning the same
Andhra Pradesh Water, Land and Trees Act, 2002Government order for all Municipalities in Andhra Pradesh
Administrative Measures Implementation Technical Incentives/ Penalties
Measures taken
Municipal Corporation of Hyderabad (MCH) has also made it mandatory to provide RWH to any additional buildings/multi stories in plots over 300 sqmAll existing Municipal building were made to undertake RWH within 1 year from the issue of Notification
Hyderabad Metropolitan Water Supply and Sewerage Board (HMWS&SB) has special Cells at their office where people can get information regarding RWHIn critical areas, HMWS&SB has constructed nearly 14,000 RWH structures
Technical experts have questioned HUDA norms for RWH structures and believe that injection wells can be made 5ft deep instead of 6.5ft deep as prescribed by HUDA
Shortfall Applications submitted for RWH by citizens to Municipal Corporation of Hyderabad (MCH), HMWS & SB and Hyderabad Urban Development Authority (HUDA) met with no or little responseRWH has not spread widely due to non cooperation of concerned departments
Government departments ask residents to contact listed contractors who claim very high ratesLack of coordination between different Government Departments dealing with RWHOut of 5,000 applications submitted, only 500 are implemented
50% subsidy announced on RWH structures was lifted due to poor response.
Incentive for RWH• GO 302 – Andhra Pradesh Revised Building Rules, 2008• Incentives for owners rain water harvesting / recycling of waste water:
• The following incentives in terms of rebate in Property tax will be given by the local authority for owners or their successors-in-interest who:
Undertake both recycling of waste water and rain water harvesting structures: 10 % rebate
Disincentive for lack of Greenery and RWH structures:• If the Greenery development as mentioned in Rule 9.9 is not provided and
maintained and Rain water harvesting structures are not provided, 10% of additional Property tax every year would be imposed as penalty by the sanctioning authority till the said condition is fulfilled.
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.
Where to do RWH ?
• Individual homes• Colonies• Apartments• Institutions• Schools/colleges/universities• Clubs• Hospitals• Industries• Slums• Every where
How much will it cost and what are the parameters that affect the cost?
Maintenance
With a base period of 10 years a rainwater harvesting construction could gain an eco-nomic benefit of 1100 INR for the exemplary slum household and 2650INR for the ex-emplary middle class household. It would take about 7 years until the investment costs amortize.
THANK YOU..
Ref: http://...