Leakage is treated water that is lost from the distribution system. It includes water lost from the companies’ distribution networks and supply pipe losses from consumers’ pipes.
Leakage is affected by:
- operational strategies (for example pressure management)
- network characteristics (for example length of mains)
- the climate (for example freezing ground in the winter or dry summers)
- asset condition (for example age)
- customer base composition (for example rural or urban)
Some leaks in water pipes are inevitable as all joints are susceptible to seepage and pipes can become damaged by ground movements caused by freezing weather or the weight of traffic on roads.
Companies have made progress in reducing leaks, and leakage is now around 35% lower than its 1994-95 high. This reduction is equal to the daily needs of nearly ten million domestic customers – more than one-sixth of the population of England and Wales.
We have a duty to make sure that companies continue to supply water to customers, so leakage levels are important to us. Companies must publish information on their total leakage each year on their websites. We have set annual leakage reduction targets for each company through to 2015 and will take action if companies fail to deliver.
We require the water companies to operate at the sustainable economic level of leakage, which identifies the level of leakage that gives consumers the best value for money. It compares the cost of reducing leakage to the costs of maintaining a balance between supply and demand in other ways, such as developing a new water resource, additional metering or promoting the efficient use of water.
As part of our 2009 price review we published guidance on best practice in including social and environmental costs and benefits in the calculation of the sustainable economic level of leakage. We are currently reviewing, alongside the Environment Agency and Defra, how this guidance was interpreted by companies.