Thames Water plans £1bn reservoir in Oxfordshire

Thames Water, Britain's leakiest water supplier, unveiled plans yesterday to build a giant £1bn reservoir to meet the increasing needs of customers in the South-east.

The reservoir, which the company proposes to put on farmland near Abingdon in Oxfordshire, will hold 150 million cubic metres of water - a little less than half the capacity of Lake Windermere. Covering 10 square kilometres (6.2 square miles), it will be the largest fully embanked reservoir in the UK and the biggest reservoir to be built in the country for 25 years.

The company, which has been put up for sale by its German owner RWE, said it was responding to changes in climate and population growth projections that envisage that, by 2030, an extra 280 million litres of water a day will be needed in London (enough to supply all of Northern Ireland) and 60 million litres a day in Swindon and Oxfordshire.

With a projected completion date of 2018 or 2019, the reservoir will supply an additional 350 million litres a day for the Thames Water network. However, that extra water 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.