A roof becomes a catchment when it is used for harvesting rainwater. Then it can be called a “Roof catchment”. Roofs are the most common types of catchment used for harvesting rainfall. Rainwater harvesting from impervious roof made of corrugated iron sheets corrugated plastic and clay tiles is a popular method for providing portable water directly from rainfall. The system provides water at home, is affordable, easy to practice regardless of physical or climatic conditions and can be designed to suit different conditions (available finances, roof area, family size, rainfall or roof area).
In most cases, roof catchment systems provide water that can be used for domestic purposes. However, roof runoff harvesting is also used for agricultural purposes including micro-irrigation of kitchen gardens, watering livestock, and for bee keeping projects. The tank size is dependent on the rainfall regime, the water demand and roof area available.