Rainwater harvesting is a way to capture the rainwater when it rains. This water is then stored above ground or charged to the underground to be used later. In rural areas, this happens naturally as the open spaces and unpaved areas soak in water. But in congested, overpaved metropolitan cities like Mumbai, we need to create mechanisms to capture the rainwater.
Rainwater can be harvested from the following surfaces:
- Paved and unpaved areas
- Water bodies
- Storm water drains
A simple rainwater harvesting (RWH) system can be installed by reorienting the plumbing design. In most of the houses or apartment blocks the rainwater from the roof and the ground level areas flows towards the street, clogging the storm water drains and sewer lines for a few days before flowing away as sewage water. Instead, you can bring the rainwater down using closed PVC pipes and direct it to a pump.
With a RWH system in place, you can reduce the amount of water used from the main supply by more than half. Collected water can be filtered and used for 60% of a normal household's water consumption.