Water butts might also be known as water tanks or water barrels. The purpose of a water butt is to collect the rainwater that may have run from gutters and roofs tops (although they can collect water from numerous places if situated correctly) and then re-use the water for a multitude of purposes.

Water from these tanks is not generally considered suitable for drinking water, certainly not without being treated first but it can be used for (watering gardens), washing outdoor equipment and vehicles or even used in washing machines.