Britain's first desalination plant to counter drought threat change

Britain's first desalination plant will be on the banks of the Thames, at Barking in east London, to counter the threat of summer droughts caused by climate change.

Britain's first desalination plant will be on the banks of the Thames, at Barking in east London, to counter the threat of summer droughts caused by climate change.

The plant, a system more usually found in the Middle East and the Mediterranean, could produce up to 150 million litres of drinking water a day from the tidal river, enough for 800,000 people.

A spokesman for Thames Water, which serves eight million customers with 27,000 million litres of water a day, said the plant would "increase capacity during long hot spells; it's for drought capacity".

The Thames Water area already relies on a greater proportion of rainfall to produce drinking water than any other area in the UK - 55 per cent, compared with just 8 per cent in some parts of Wales - and is now looking for other reliable water sources. "If we could get more from river or underground sources then that's something we would want to pursue," the spokesman said.

The Thames Water desalination process is called reverse osmosis, in which salty water is forced through a membrane to remove the sodium and chloride ions that make it salty. At the Barking plant, this process would be repeated four times. The water will be sent to a purification plant to be treated then held in a reservoir at Woodford, Essex which serves north-east London. Reverse osmosis is typically used in Mediterranean countries, which often rely on desalination to augment their fresh water supply.

Thames Water hopes to have the plant working by 2007. It will ease the task of removing the salt by taking in water only when the tide is retreating, leaving the Thames only one-third as salty as the sea. Even so, the company admits that the plant will need six megawatts of electricity to run, a considerable increase in energy usage.

Friends of the Earth said yesterday: "We have concerns about the energy consumption, and the possible effects on marine life, and we are considering our position."

South East Water is believed to be considering building a desalination plant on the south coast.