This year’s historically rainless UK summer, fuelled by the climate crisis, saw hosepipe bans and two thirds of England officially in a state of drought, putting water security top of mind.
The UK gets most of its water from rivers, lakes and reservoirs. But climate change, a growing population, and rising demand from irrigation for crops and (controversially) for AI data centres, have fuelled concerns about the country running short of water, with some projecting a 5 billion litre deficit every day by 2055.
The government’s 2025 National Framework for Water Resources has steps to tackle this, including funds to build ten new reservoirs, nine water transfer schemes, and two desalination plants.
What is desalination?
Desalination is the process of removing salt from seawater (mostly from the ocean) to produce freshwater which can be used for drinking, cooking, and washing.
In the most common method, desalination plants force seawater through a membrane which lets water molecules through but blocks most salts and other unwanted bits, producing usable freshwater and a dense salt solution called brine. An older method heats saltwater into vapour, and condences it back into saltless liquid.
Desalination is widely used in areas without access to freshwater such as the Middle East and parts of Africa, Asia and the United States, with roughly 20,000 desalination plants around the world.
This makes the process an essential source of the water people rely on to survive. However, it does have some negative effects on climate and the environment.
Desalination uses a lot of energy, producing between 500 and 800 million tonnes of carbon dioxide (CO2) emissions every year according to a 2025 study. The leftover brine is also dumped in the ocean, where it damages coral reefs. However, there are efforts to clean up the process, for example by powering it with electricity from renewable sources.
Will desalination help the UK’s water supply?
There are some reasons to worry about whether the UK can become a desalination nation. Right now the country only has one desalination plant, the Thames Gateway plant in Beckton, east London, operated by Thames Water, best known for pumping sewage into UK rivers.
Despite Thames water flows dropping to 3,000 megalitres per day – the company’s trigger for action under its own drought plan – the plant has not produced any water all summer, with the company citing technical issues it hopes to resolve by the winter. This is obviously too late to help the summer drought. The plant has reportedly only been used five times since 2010, producing the equivalent of seven days’ water in 15 years.
Some campaigners argue that it would be better to focus on building more reservoirs, which can store fresh water and capture extra rainfall without needing so much energy or emitting as much carbon dioxide.
No new reservoirs have been built in the UK since 1991, with planning and financial constraints blamed. In Oxfordshire, an ongoing planning row continues over the proposals for the White Horse Reservoir, with more than 8,000 people having opposed its construction. Thames Water has said it will only be available to use from 2040 if the government approves plans.
What happens next?
There are plans to build several desalination plants around the country, with Anglian Water proposing sites in Norfolk and Lincolnshire, and Southwest Water looking to open a plant in Cornwall.
Prime Minister Andy Burnham this week called the UK’s water industry “a leaking monument” to the failure of “a country run in the private rather than public interest”, adding: “This summer has shown us very clearly that water companies are failing to rise to the climate challenge.” He has suggested he might nationalise Thames Water, or at least put it into special administration. A “ten point plan for Britain” will be published later this year and include “plans for stronger public control over these essentials”. ■
About the author: Adam Barnett is UK News Reporter at DeSmog and a freelance journalist. He writes a politics column for the Big Issue and has reported for The Guardian and Private Eye
About The Lead Untangles: In an era where misinformation is actively and deliberately used by elected politicians and where advocates and opposers of beliefs state their point of view as fact, sometimes the most useful tool reporters have is to help readers make sense of the world. If there is something you’d like us to untangle, email ed@thelead.uk and you can see every edition of The Lead Untangles so far.
👫Found this edition of The Lead Untangles useful? Share this story with your friends, family and colleagues to help us reach more people with our independent journalism, always with a focus on people, policy and place. And catch up on the series so far where we looked at the human cost of extreme heatwaves, the growth of regenerative farming, the environmental impact of data centres and the pressure growing for North Sea drilling.
Get the next instalment of The Lead Untangles direct to your inbox as part of our focus on climate and environment and also get 30 per cent off an annual subscription (usually £49, use this link to get it for £34.30 instead) to help us combat misinformation.
Would there be any milage in linking data centres with desalination plants? We're told the vast water resources needed for these are to cool them down. Could sea water be used and in the process produce freshwater?