Which is the first state in India to have made roof top rainwater harvesting structure compulsory for all the houses across the state? 

The correct answer is Tamil Nadu.

• Tamil Nadu is the first state in India which has made rooftop rainwater harvesting structure compulsory to all the houses across the state.
• Rooftop rainwater harvesting structure is the part of the technique through which rainwater is captured from the roof catchments and stored in reservoirs.
• The act of collecting, diverting and storing water from rain events for later reuse is called rainwater harvesting.

Important Points

• Tamil Nadu was the first state in India which launched the rooftop rainwater harvesting and made it compulsory for every building to avoid groundwater depletion.
• The rooftop rainwater harvesting model of the Tamil Nadu government gave an excellent result within five years and led to a 50% rise in water level in five years in Chennai.

Additional Information

• The RainSaucer, Groasis Waterboxx and various others are the newly developed approaches for the purpose of the rainwater harvesting.
• Frankfurt Airport has the biggest rainwater harvesting system in Germany.