Describe the working of the rooftop rainwater
harvesting being practised in India
or '
Describe the procedure for rooftop rainwater:harvesting.
Ans. 
The figure below shows a typical method of rooftop’rainwater harvesting being practised in India. The rainwater falling on the roof is collected by a PVC pipe and filteredusing sand and bricks, before being taken underground to a sump for immediate use. Excess water from the sump is 'transferred to a well, which recharges the groundwater. further requirement of water can be taken from the well.