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Thames Water on alert to re-activate UK’s only mainland desalination plant

The UK’s only mainland desalination plant may be restarting operations later this year, says Thames Water.

The utility firm, which operates the plant in Beckton, east London, is on alert to activate the facility as London reservoir storage reaches 74%, far lower than expected for this time of year. 

July rainfall in the Thames catchment area was less than 1mm, which is 2% of the long-term average. Customers used about 100m litres more water a day than normal, putting pressure on rivers, reservoirs and the water network. 

The plant was originally opened in 2011, and was designed to use seawater from the Thames estuary in times of drought. The utility company said restarting operations at the Beckton plant could help build up reservoir supplies over the winter for next summer.

There is no official trigger for switching on the Beckton plant and doing so would potentially require weeks of preparation. A decision to switch the plant on would represent the first time it had ever been activated as an emergency measure.

A Thames Water spokesperson said: “Preparations are under way at the Thames Gateway water treatment works in Beckton, east London, so it can be brought online by the end of the year, if needed, to help support reservoir recovery over the winter… Any decision to use the desalination plant will depend on weather conditions, demand, and reservoir levels in the coming weeks.”

A white knight or white elephant?

Desalination plants are more commonly used in the Middle East to provide drinking water. MPs have expressed frustration in recent years that the plant has not been available to provide drinking water during heatwaves.

Yet, according to reports by the Guardian, the desalination plant in Beckton has long been regarded as a white elephant.

The Beckton plant has only ever run five times, providing just 7.2bn litres of drinking water – equivalent to just seven days’ worth of the capital’s daily demand over 15 years. However, more than £270m was spent on its instillation and despite barely operating over the last 15 years its total cost is now estimated at £500m.

Thames Water’s performance during the drought will be closely scrutinised, with the prime minister, Andy Burnham, due to decide the company’s future in the coming weeks. Burnham recently expressed his anger after 13 companies were allowed to increase bills to fund extra projects, stating water customers were not a “bottomless source of funding”. Thames Water was one of five companies permitted to raise bills in the next four years.

Operating the Beckton plant may not be financially attractive for Thames Water either, with exorbitant electricity costs. Thames Water is under severe financial strain, with its creditors effectively taking control of the business for two years while seeking leeway from the government on fines for pollution before formally taking over. Chris Weston, Thames Water’s chief executive, last year told MPs on the environment committee that the Beckton plant had serious problems and no way of testing crucial equipment such as membranes. “The desalination plant is a big problem for us,” Weston said. “I wonder why it was built in the first place. It is not a good story, it was not a good investment, and there are no excuses about it.”

However, operating the plant in cooler temperatures could potentially improve its financially viability if wind power is in abundance and there is less strain on the grid, in turn lowering electricity prices.