Boreholes reveal hidden signs of UK drought problem

When the water dries up we tend to think of half-empty reservoirs. But in East Sussex the problem is a little more hidden.

There are over 250 boreholes in the South East Water region - a huge number, and they supply 75% of the water in the area.

The borehole at Friston Treatment Works, near Eastbourne, is big enough to climb down (with a camera crew too). It's a hundred feet down and it takes about half an hour to get to water.

At the moment it takes just a little longer. The lack of rain means water levels are two and a half metres below what they should be.

The borehole collects water that percolates through the ground above. A two and a half-mile tunnel - dug by Welsh miners nearly a hundred years ago - brings the water to a well.

It is then pumped to the surface, treated and ends up in people's homes.