Most of the water (about 90%) supplied to customers in the South West is taken from surface water (rivers or reservoirs). The rest is supplied from water-bearing rocks below ground known as aquifers.
The rocks in an aquifer can hold water just like a sponge.
The water can be pumped out by drilling a borehole or digging a well down to the level of the water. In some areas, where the water is under pressure, it may rise to the surface without pumping. This is called 'artesian flow'.
The Environment Agency is responsible for controlling the amount of water taken from rivers, reservoirs and aquifers. South West Water must get a licence before it can take water from any source.
The company must also make sure that the water which goes back into rivers meets the Environment Agency's consent conditions.