Examine the importance of ‘rain water harvesting’.

Rainwater harvesting is the technique of collecting and storing rainwater for various uses. The process involves preventing rainwater from going unused as surface run-off into other water bodies. The stored rainwater is also used to recharge groundwater aquifers. Rainwater harvesting, thus, increases water availability, checks the declining groundwater table, improves the quality of groundwater through dilution of contaminants, prevents soil erosion, and flooding and arrests saltwater intrusion in coastal areas if used to recharge aquifers. This low cost and eco-friendly technique for preserving every drop of water is a boon to regions with erratic rainfall.