Britain's leakiest water supplier has published plans to build a £1 billion reservoir to meet increasing demand in generations to come.
Thames Water is proposing to build the reservoir on farmland near Abingdon in Oxfordshire to cope mainly with London's growing need for water.
If it goes ahead, it will be the country's largest-ever fully embanked reservoir and the biggest to be built in the UK for 25 years.
With a projected completion date of 2018 or 2019, it will hold 150 million cubic metres of water - just under half of Lake Windermere's volume - and will supply an additional 350 million litres a day for the Thames Water network, but the extra water provided falls far short of the estimated 900 million litres a day - a third of all the company's supply - currently being lost through leaky pipes under the streets of London.
Thames Water's environment director, Richard Aylard, said the company was aiming to cut leaks to 720 million litres a day, the company's "economic level of leakage".
Cutting leaks below this threshold becomes too expensive, he said.
Even if this level is achieved, daily leakage would still far surpass the amount of water supplied to the network from the proposed reservoir - totalling four square miles - in Oxfordshire.
Mr Aylard said 200 miles of piping was currently being replaced each year in London's antiquated supply network, which has 10,000 miles of pipes. Thames Water claims to spend £500,000 a day on repairs.
In addition to the company's much-publicised leakage woes, customer demand is set to rocket over the next three decades. London's population is expected to rise by 800,000 in the next decade alone and British summers are predicted to get hotter and drier.
A spokesman for Ofwat, the regulator for water companies in England and Wales, said Thames Water was by far the UK's leakiest supplier, followed by Severn Trent in the South West and United Utilities in the North West.
