Collecting, storing and using the rain falling on roof tops of houses and buildings. Rainwater is both clean and soft. It is the least cost form of water supply. Storage of rain water reduces chance of floods. It reduces incidence of soil erosion and hence siltation of lakes. It helps in ground water recharging.


How is Roof Top Rain Water Harvested?

• Collecting the water from roof top.
• Through gutters divert them to a convenient point.
• Draw it down through down pipe.
• Filter the water and then
• Store in a sump or tank for later use.
• Charge the ground water through a soak pit.
• Leave the water in to a well to increase ground water content.

RWH Filter Devices Conical mesh Filter

Self-cleaning removes leaves twigs and other solid particles more than 2mm thick

First Flush Device

It is a plastic or PVC drum, it avoids the first batch of dirty water when every time rains. It has a simple floating ball valve and has 50ltr/100ltr storage capacity.

Sand Filter

It consists of a plastic barrel with perforated inlet and outlet pipes. It contains layers of pebbles, coarse, grades sand, Nylon mesh and sponge. This isolates most of the particulate matter floating in water.




Plastic lined tanks


Rainwater can be stored in dug out plastic lined tank of trapezoidal shape. The plastic is strong and is stable under ultra violet radiation. Catchments consists of several roof tops and paved areas. A fence is provided all around to prevent entry of people and animals. Water stored is pumped using a motor.



Percolation well





Percolation wells are of 100-300mm diameter are generally constructed for recharging the deeper aquifers of water and water is passed through filter media to avoid choking of recharge wells.








Recharge pit




To facilitate easy percolation of water inside soil recharge pit/trenches are constructed. These are constructed 1-2m wide and 2-3m deep which are back filled with boulders, graded metal and coarse sand.