Rainwater harvesting is a method to capture and store rainwater for various uses. It is also used to recharge groundwater aquifers. It is a low-cost and eco-friendly technique for preserving every drop of water by guiding the rainwater to borewells, pits and wells. Rainwater harvesting increases water availability, checks the declining groundwater table, improves the quality of groundwater through the dilution of contaminants, like fluoride and nitrates, prevents soil erosion, and flooding and arrests saltwater intrusion in coastal areas if used to recharge aquifers.

What is the name of the underground tank constructed in Rajasthan for harvesting rainwater called?

Kund

In Rajasthan, rainwater harvesting structures locally known as Kund or Tanka (a covered underground tank) are constructed near or in the house or village to store harvested rainwater.