Rainwater Harvesting
- Rainwater harvesting is a technique of collecting and storing rainwater for future use.
- It is a traditional method of storing rainwater in underground tanks, ponds, lakes, and check dams and used in future.
- The main purpose of rainwater harvesting is to make the rainwater percolate under the ground so as to recharge ‘the groundwater level’.
Methods of rainwater harvesting
- Rooftop rainwater harvesting: Rooftops are excellent rain catchers.
- The rainwater that falls on the roof of the houses, apartments, commercial buildings etc. is collected and stored in the surface tank and can be used for domestic purposes.
- Recharge pit: In this method, the rainwater is first collected from the rooftops or open spaces and is directed into the percolation pits through pipes for filtration.
- After filtration, the rainwater enters the recharge pits or ground wells.
- People living in rural areas adopt a variety of water collecting methods to capture and store as rainwater. Some of the methods used are
Digging of tanks or lakes (Eris):
- It is one of the traditional water harvesting systems in Tamil Nadu.
- Eris is constructed in such a way that if the water in one eri overflows, it automatically gets diverted to the eri of the next village, as these eris are interconnected.
Ooranis:
- These are small ponds to collect rainwater.
- The water is used for various domestic purposes (drinking, washing and bathing). These ponds cater the nearby villages.
Advantages of rainwater harvesting
- Rainwater harvesting helps to
- Overcome the rapid depletion of groundwater levels.
- To meet the increasing demand of water.
- Reduces flood and soil erosion
- Water stored in the ground is not contaminated by human and animal wastes and hence can be used for drinking purposes.