3. DONE BY  PREETHY.P  MEERA KUMAR {X-O}  STEFFI SAM GOVT.H.S.S.FOR GIRLS,COTTON HILL

4. INTRODUCTION The ancient civilization flourished along the bank of rivers,where water was freely available.As the population grew,man had to move away from rivers and for the needs of water, had to search for solutions like storing of rain water or surface run-off. Thus emerged the practice of water harvesting.

5. AIMS To study about water harvesting. To promote the conservation of water. To spread awareness & interest among the public.

6. DATA COLLECTION Rainwater harvesting means making use of each & every drop of rainwater to recharge the groundwater, by directing the rainfall to go into the well or under the ground, without wasting the same.

7. RAINWATER HARVESTING The main aim of water harvesting is to conserve rainwater in the areas where it falls so that it may satisfy local needs. Harvesting rainwater & recharging the water table can be achieved through the following methods:  By using the existing well  Through percolation pits  Decentralized percolation trenches

8. The following are some methods used to recharge the ground water: Pebble bed method Percolation pits Recharge wells Ridges & furrows Check dams Gully control / stone wall structures Contour bunding & trenching Land flooding

9. Planning & Designing the water harvesting system The main components involved in the planning design of a rainwater harvesting system are:  Roof [catchment area]  Annual rainfall – Minimum 10 years average & if possible 50 years average is taken.The wastage is considered about 25% of total rainfall.  No: of persons in the family.

10. How much water can be harvested ? The following is an illustrative theoretical calculation that highlights the enormous potential for rainwater harvesting. Area of plot = 100 sq.m. Height of rainfall = 1.1 m [1100 mm or 44 inches] Volume of rainfall = Area of plot * Height of rainfall = 100 sq.m. * 1.1m =110 cu.m. Assuming that only 60% of the total rainfall is effectively harvested, volume of water = 66,000 liters This volume is about four times the annual drinking water requirement of a five member family.The average daily water requirement per person is 10 liters according to IS 1172:Indian Standard Code of Basic Requirements for Water Supply, Drainage & Sanitation.

13. Conclusion Rainwater harvesting is simple & cost effective.If such simple measures to “Catch water where it falls”, is taken by individuals,most of the water management problems in our state can be solved.The scope for development under Panchayat Raj should be fully utilized to conserve precious fresh water to solve the water scarcity. Harvesting & conserving water is every individual’s duty.Every drop of rain water is precious-save it.It might be the very drop that will quench your thirst one day.

14. Suggestions Reduce your needs. Reuse or recycle as much water as you can. Harvest & conserve water. Take initiatives in conserving &preserving this life-giving resources for posterity.

15. BIBLIOGRAPHY Hand book on rainwater harvesting, Malanadu Development Society Rainwater harvesting,GOI, Department of Rural Development, Ministry of Agriculture, may 1990 Water-the elixir of life - 2003 C.P.R. Fresh water resources of Kerala -2004 KSCSTE,KERALA