A water catchment is the area of land on which rain falls then drains down into rivers, lakes and the sea.

It usually includes mountains and hilltops. This water is collected and stored in dams.

A much smaller water catchment is the roof of your house. Rain falls on the roof, drains off it into the gutters and can be collected in a rainwater tank. It’s your own personal water catchment.

So, a catchment can be any surface area where rainwater can be collected and drained into a container (big or small) for storage.