1. RAIN WATER HARVESTING By WESI Water and Energy Strategy Institute
E mail:
Ramadhan Hamza
JAN/9/2019

2. Contents Introduction Objectives What is rain water harvesting?
Necessity of rain water harvesting.
Methods of rain water harvesting.
 Advantages of rain water harvesting.
Conclusion

3. Introduction
RWH is an outcome of awareness among the people regarding the water scarcity. Typical features of Rain Water Harvesting :- Reutilization of waste water. As RWH -neither energy-intensive nor labor-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

4. OBJECTIVE The main objectives of rain water harvesting are :-
1.Promote rain water harvesting by creating awareness among the people.
2. Increasing the availability of ground water during periods of requirement.
3. Preventing depletion of ground water reservoir in areas of over exploitation
4. Decreasing menace of flood on local and regional scale
5. Reducing pressure on storm drains in urban areas
6. Enhancing the quality of environment.

5. What is Rain Water Harvesting?
Water is our most precious natural resource and something that most of us take for granted. We are now increasingly becoming aware of the importance of water to our survival and its limited supply, especially in regions that will be effected by climate change as our region.
The harvesting of rainwater simply involves the collection of water from surfaces on which rain falls, and subsequently storing this water for later use. Normally water is collected from the roofs of buildings and stored in rainwater tanks. This is very common in rural Areas. Water can also be collected in dams from rain falling on the ground and producing runoff.
Either way, the water collected can be considered to be precious

6. How To Harvest Rain Water?
The six basic components of a rain water harvesting system include:-
1.Catchment:
Roof surface to collect rain.
2.Conveyance:
Pipes from roof area to storage.
3. Roof Washing:
First flush diverter to filter and remove contaminants.
4.Storage:
Tanks where collected rain water is collected and stored.
5.Purification:
Includes artificial filters, sand filters to remove suspended impurities
6.Distribution:
System that delivers the rain water, usually including small pump and pressure tank

7. Methods of rain water harvesting
Roof Top Rain Water Harvesting System Dam Rain Water Harvesting System

8. Rainwater harvesting/Catchment and storage dams
Water can be made available by damming a natural rainwater catchment area, such as a valley, and storing the water in the reservoir formed by the dam, or diverting it to another reservoir. Dams can consist of raised banks of compacted earth (usually with an impermeable clay core, stone aprons and a spillway to discharge excess runoff), open rock reservoir catchments, and masonry or concrete (reinforced or not).
Open reservoirs behind a retaining structure have storage capacities ranging from 20 – 4,000 m³. Alternatively, a volume of water could be stored directly into covered storage tanks that collect water directly from the catchment.
The water stored behind a dam should normally be treated before entering a distribution system

9. recharging Groundwater Well Recharging Method

10. When Does RWHS Work?
Conditions Suitable for RWHS Conditions Unsuitable for RWHS
High mean annual rainfall with low inter-annual variability
Rainfall spread over large number of rainy days
Hilly areas with scattered populations
Houses with large per capita roof area in cities
Low mean annual rainfall with high inter-annual variability
Intense rainfall in few rainy days with little gap between two wet spells
Plains with dense settlements
Houses with small per capita roof area like multi-storey apartments

11. Rainwater 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

12. CONCLUSION
Rainwater harvesting is an ancient practice that stills holds many benefits and value for our modern times. It provides an alternative water source while allowing you to control and operate the system as you see fit. Rainwater collection can also teach valuable lessons in water conservation which is becoming more important as our freshwater resources get stretched further and further..
Since produce energy is looking costly, but we can save it by preventing wastage.
In the same way we cannot produce water, but save it and protect our future

13. THIS IS NOT THE END, JUST THE BEGINNING, SO START THE HARVESTING OF WATER, AND SAVE OUR PLANET.

15. Thank you