Which of the following is NOT a benefit of rainwater harvesting?

none of the above

The correct answer is Option 4: none of the above

Option (1): Help in recharge of groundwater aquifers. — This statement is correct. Rainwater harvesting allows rainwater to seep into the ground and recharge groundwater levels.

Option (2): prevents soil erosion — This statement is correct. Rainwater harvesting reduces surface runoff, which helps in preventing soil erosion.

Option (3): improves the quality of groundwater — This statement is correct. Recharge through rainwater can dilute contaminants and improve groundwater quality.

NCERT: 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 rain water to borewell, pits and wells. Rainwater harvesting increases water availability, checks the declining groundwater table, improves the quality of groundwater through dilution of contaminants, like fluoride and nitrates, prevents soil erosion, and flooding and arrests salt water intrusion in coastal areas if used to recharge aquifers.