Rain-water Harvesting

Rainwater is biologically pure, soft in nature and free from organic matter. Rainwater har vesting is an effective technique of conserving water by guiding the rainwater that falls on rooftops to storage tanks or underground pumps for future usage. Groundwater recharging, on the other hand, is undertaken by guiding water through pipes to wells, bore wells or recharge pits to ensure recharging water in the underground aquifers, for later use, whenever the need arises. Tamil Nadu is the first and only state in India which has made roof top rain water harvesting structure compulsory to all the houses across the state. There are legal

provisions to punish the defaulters.

The collection of water from a catchment surface is referred to as rainwater harvesting. Water harvesting also includes activities aimed at harvesting surface and groundwater and other techniques aimed at conservation and efficient utilisation of limited water endowment. In general, water harvesting is the activity of direct collection of rainwater. The collected water can be stored for direct use or can be used to recharge the groundwater.

The quantum of harvested rainwater depends on:

1. Frequency, duration and intensity of rainfall.

2. Nature of catchment.

3. Run-off characteristics.