They usually go out at night when it's quiet to find the leak by listening to the flow of water (a hissing or rumbling sound) escaping from the pipe

Lots of reasons: pipes are old or damaged; cold weather can freeze and crack them; tree roots and even building work can cause damage.

We may have to arrange an alternative water supply to customers and need to let them know how this will affect them. If roads need to be closed or diversions put in place we work with local authorities to make sure we keep the public safe. Sometimes problems also come up and we find we need different parts or equipment to fix the leak. When we dig down we sometimes find that other utilities near to the pipe are damaged, and they often have to be fixed first.