Q. Which state of India has made rain water harvesting compulsory for all houses?
Answer: Tamil Nadu
Notes: Rainwater harvesting has been made compulsory for every building in Tamil Nadu to avoid ground water depletion. Since its implementation, Chennai saw a 50 percent rise in water level in five years and the water quality significantly improved. Rainwater harvesting is the accumulation and deposition of rainwater for reuse on-site, rather than allowing it to run off.