Water catchment systems divert and store rainwater, providing a clean, free water source that reduces stormwater runoff as well as demand on potable water supplies.
A typical system collects water from a roof piped to a storage tank where it can be used for both potable (drinkable) and non-potable purposes such as landscaping, toilet flushing and clothes washing. Each square meter (square foot) of roof area will capture 7.37 liters (0.46 gallons) of rainwater for one centimeter (inch) of rainfall.
Sizing the system:
- Storage tank capacity (liters) = water catchment area (m2) x rainfall (cm) x 7.38
- Storage tank capacity (gallons) = water catchment area (ft2) x rainfall (inches) x 0.46
Where rainfall = peak monthly average.
The larger the storage tank, the longer water will be available between rain events. Rainwater intended for potable use must be treated using appropriate filtration and disinfection methods.