Why a hosepipe ban in England's wettest region?

Six months ago parts of north-west England flooded and residents waded knee-deep in muddy water. Now, heading into high summer, a hosepipe ban looms. So why is it suddenly so dry?

Measures of rainfall, soil moisture, river flows and reservoir stocks all show north-west England is low on water.

This week United Utilities, the water company that provides water to the region's seven million people, applied for a drought permit. A look at reservoir stocks across England and Wales shows only the Colliford reservoir on Bodmin Moor, Cornwall, has above average stocks.

In the past six months the North West has had much less rain than normal, with certain areas having less than 60% of the long term average. In the past five months, the North West has had its lowest rainfall since 1929, says the Environment Agency.

As rainfall has dropped, so has the water level of its reservoirs. This is because the region is unusual in that it lacks large underground aquifers that can soak up and store rainwater, and so is far more reliant on regular rainfall to keep its supplies topped up.

"Despite receiving record-breaking levels of rainfall in November 2009 in Cumbria, our drinking water relies on water from rivers, lakes and reservoirs," says an Environment Agency spokesperson. "These are sensitive to changes in the weather, responding quickly to heavy rainfall or dry periods."