How do leaks happen?
Leaks happen for a variety of reasons. Temperature changes, such as fierce winters, can cause the ground to move, putting significant pressure on our underground water mains and fracturing them.

Illegal standpipes, high-level commercial usage and other industrial misuse can also cause unexpected, high pressure surges in the water main which also cause bursts.

In addition, many of the pipes within our 13,700km water main network are made of iron and were laid in the 1930s. These pipes have stood the test of time, but are starting to show their age.

Domestic leaks – leaks inside the home or property boundary - also cause problems for many customers. Read more about domestic leaks here.

How do you find them?
We discover leaks by investigating unexplained high water-usage spotted by our monitoring systems or by responding to customers who call our freephone leakline (23,549 people reported leaks to us this way in 2010).

Once we have identified the local area of a leak, our leak detection staff use a combination of sophisticated acoustic equipment and traditional listening sticks to pinpoint the exact location.

What then? How quickly are they fixed?
Once located, engineers are despatched to make the necessary repairs. Our target is to fix 80 per cent of leaks within five days and all leaks within 10 days.

We are constantly surveying and repairing our water network to minimise the threat of future leakage problems.

We are also replacing hundreds of kilometres of mains with flexible plastic pipes to protect water supplies from leakage well into the future.