By John — Desalination News
Thames Water says it plans to bring the UK’s only desalination plant back online by the end of 2026, restarting a facility that has run just five times since it opened — and doing so right as the drought that prompted renewed interest in it looks set to ease.
A plant built for emergencies, rarely used
The Thames Gateway Water Treatment Works in Beckton, east London — commonly known as the Beckton desalination plant — opened in 2010 as a drought-resilience measure for the capital, drawing brackish water from the tidal Thames and treating it via reverse osmosis. It was originally designed to produce up to 150 million litres a day, enough to supply around 900,000 Londoners, or roughly 400,000 households, during periods of high demand.
In practice, the plant has been switched on only five times in over a decade of operation, together providing about seven days’ worth of London’s typical water supply. Its capacity was also revised down, from 150 to 100 million litres a day in 2022, and by 2025 it was reportedly running at around two-thirds of even that reduced figure when in use.
Cost has more than doubled
The original construction cost, including its dedicated pipeline, was put at £250 million. By September 2025, cumulative costs associated with the scheme had climbed to roughly £518 million — the figure now widely cited, including in coverage of this restart, as “£500 million.”
Why restart now?
According to reporting on the restart plan, Thames Water’s rationale isn’t to fix today’s drought — it’s to rebuild reservoir levels through the winter months so the network heads into next summer with fuller reserves. The timing has drawn scrutiny: UK drought conditions are expected to ease before the plant is even back in service, leaving a gap between when the facility switches on and when the water pressure it was built to relieve is actually being felt.
That mismatch has reignited a broader debate around the Beckton plant specifically, and desalination-as-drought-insurance more generally: is it sensible for a capital-intensive, energy-hungry asset to sit idle for years at a time, only to be activated on a schedule that doesn’t line up with acute need? Critics point to the plant’s underwhelming utilisation record as a caution against over-relying on desalination as a standalone drought fix, rather than one tool among several — leakage reduction, reservoir expansion, and demand management among them — in a water-stressed region, a tension also playing out as Southern Europe weighs how far engineering alone can solve chronic drought.
What’s next
Thames Water has not set an exact restart date beyond “by the end of the year,” and has not detailed how long this run will last or what output level it will target given the plant’s history of operating below even its reduced nameplate capacity. Desalination News will track the restart and report on actual output figures once the plant is back in service.
(Source: EnviroLink Network) (Source: Wikipedia)