Currently a lot of existing buildings do not have systems through which they can harvest rainwater but can start doing so easily with a few simple steps.
Step 1: Identify a suitable catchment area
In most of the cases, the roof of an existing structure is best suited as a catchment area for rainwater harvesting.
Step 2: Estimate Rainwater Harvesting Potential
Estimating the rainwater harvesting potential from the catchment area helps fashion and install a correct storage or collection tank for the harvested rainfall.
Formula to estimate Rainwater Harvesting Potential = Surface Area of catchment (sq. ft.) x Runoff Co-Efficient of Catchment Surface x Amount of Rainfall (mm)
Step 3: Select or Design Water Storage or Collection Tank
It is difficult to select the correct size of a storage or collection tank in an existing building.
Size of tank is affected by:
Available Space
Estimated Rainwater Harvesting Potential
Purpose of the harvested rainwater
Step 4: Connect existing Plumbing services of the building to selected tank
Every structure installs plumbing services such as PVC pipes to direct rainwater falling on the rooftops to the catch basins of buildings.
In most cases, the same pipelines can be used to direct the rainwater from the roof to the designed or selected water storage/collection tank.
Meenakshi Arora
Team GreenSutra®