METHODS OF RAINWATER HARVESTING
1. Surface run off Harvesting
2. Roof top rainwater Harvesting.
Surface runoff Harvesting
1. Surface runoff harvesting is most suitable in urban areas. Here rainwater flows away as surface run off and can be stored for future use.
2. Surface runoff rain water in ponds, tanks and reservoirs built for this purpose. This can provide water for farming, forcattleandal so for general domestic use.
3. Without sufficient water health and hygiene are severely affected. This adds to the environmental pollution.
4. Surface water can be stored by redirecting the flow of small creeks and streams into reservoirs on the surface or underground.
Rooftop Rainwater Harvesting
1. Rooftop water harvesting can bed one in individual homes or in schools.
2. For this the first requirement is to intercept the rainwater to flow towards a definite direction
3. The water should reach a bucket or a tank through pipes made from wood or bamboo. In urban areas pvc pipes can be used.
4. The rain water can be directly collected by keeping a bucket or container beneath the roof.
5. Thefirstflowofrainwaterwillusuallycarrywithitdustparticles,leaves, insects and bird droppings. So it is best to use a detachable downpipe to divert the first rain water.
6. Recharge pits can be constructed to hold rain water. These can be of any shape or size, depending upon the amount of rain the area receives. These pits need to be filled with, boulders, gravels and coarse sand, which will actasafilterfortheimpuritiesthatarecarriedalongwiththefirstflowof water.
7. Roof top rainwater can be harvested through existing tube wells. In areas where the aquifer that holds the ground water has dried up, tube wells source deeper into the soil for water.
8. Roof top rain water harvesting can be done through these dried up tube wells to rehydrate the dried subsoil water level.
