- Surface area of catchment in sq. ft.
- Runoff Co-efficient of catchment surface.
- Amount of water received in rainfall in mm.
(Amount of rainfall can be found out from local authorities website or any other local news sources)
Formula to calculate rainwater harvesting potential:
Rainwater Harvesting Potential = Surface Area of catchment (sq. ft.) x Runoff Co-Efficient of Catchment Surface x Amount of Rainfall (mm)