• HOME
• • National Code of Conduct
• ABOUT NJUG
• • ADVANCED CO-ORDINATION GROUP
  • WHAT IS NJUG?
  • OUR MEMBERS
  • KEY STATISTICS
• PUBLICATIONS
• • PAPERS
  • SUSTAINABILITY
  • RESPONSE SUBMISSIONS
  • GOOD PRACTICE CASE STUDIES
  • NJUG VISION
• BECOME A MEMBER
• • WHY JOIN NJUG?
• EVENTS
• • NJUG AWARDS 2010
  • Past NJUG Awards
• MEDIA RESOURCES
• • MEDIA COVERAGE
  • VISION ENDORSEMENTS
  • PRESS RELEASES
• LINKS
• CONTACT DETAILS / OFFICE LOCATION

KEY STATISTICS

Water industry statistics

The industry supplies services to more than 20 million properties – the vast majority of the UK’s population. More than 700,000 kilometres of mains and sewers are buried beneath the ground – that’s enough to stretch to the moon and back, or a distance 200 times greater than the UK’s entire motorway network.

The total cost of replacing all the industry’s physical assets in England and Wales would be over £200bn. Three quarters of this is below ground. Collecting and dealing with wastewater costs more than supplying drinking water, mainly as larger pipes are needed. It would cost twice as much to replace the sewerage system than the water supply.

In England and Wales there are 325,000kms of mains and millions of joints in the water supply system serving 23.6 million service connections. On average each kilometre of main serves 73 households.

Mains vary significantly. Trunk mains, which transport water in bulk, can be 300mm to 1,800mm in diameter. Local distribution mains are usually smaller, with 125mm being a common size. Households are connected to the mains via service pipes. They are quite small, 25mm.

Clean water has to be delivered under pressure so that it flows rapidly out of customers’ taps wherever they live, at the top of a hill or the bottom of a valley. That means that gravity often has to be supplemented by pumps. As clean water is under pressure it will find any holes in the pipe. In the worst cases this will cause a major burst. The pressurised system means that there is no risk to the quality of the water itself as untreated or polluted water cannot seep into punctured pipes.

Most properties (more than 90%) are also connected by sewers to sewage treatment works (STW’s).

Sewers flow to the nearest STW. As there are a lot of STW’s the route from a property to a works can be quite short. A diagram of a sewage system looks more like a river system or the root system of a tree than a network such as tube lines in central London.

Today sewers are built separately from surface water systems that collect rainwater running off roads. However many older sewers are combined and serve both purposes. This is fine until the system fails to cope with exceptionally heavy rainfall. Climate change and the fact that more and more land is built on makes it harder for soil to act as a natural sponge and has made such exceptional conditions less rare.

Pipe and sewer networks are fairly robust with a long life expectancy but maintenance is still necessary.

Clean water in itself does not make big demands on the distribution network, but constant use, varying flows and the fact that water is under pressure will eventually expose any weaknesses.

Pipes become damaged or dislocated by traffic vibrations and changes in ground conditions. In recent years the ground shifts that occur in extreme droughts, which are visible on the surface in deep cracks have increased this damage.

For sewers, the main problems are blockages, collapses and overflows. Large foreign objects in the sewers can cause blockages. Collapses usually happen when sewers that are already in a poor state are exposed to persistent heavy traffic.

NEWS & DEVELOPMENTS