Plant backs up London water supply

Thames Gateway Water Treatment Works, at Beckton in east London, will, when required, turn a mixture of seawater and river water from the tidal River Thames into high-quality drinking water for up to one million Londoners.

The opening of the £270m facility this week marks the latest addition to Thames Water’s efforts to ensure that it can meet the demand for water. According to the utility, the ongoing replacement of London’s leaky Victorian water mains has helped cut leakage by more than a quarter in the past five years.

London is classed by the Environment Agency as ‘seriously water-stressed’, which means that demand could outpace supply in a long dry period.

With climate change threatening hotter, drier summers and an additional 700,000 people forecast to move to London by 2021, it is hoped that the new water works can help provide the capital’s supplies for the future - regardless of the weather.

The key treatment process in desalination is reverse osmosis, which involves forcing salty water through extremely fine membranes. This technology is used at 14,000 water treatment plants across the world and has kept crews on Royal Navy ships refreshed for decades.