London’s desalination plant won’t be fired up even if official drought is declared

It was opened by the Duke of Edinburgh in 2010 and promised to be the saviour for thousands of Londoners in case of drought.

Twelve years later, its moment arrived during the driest July on record – but the desalination plant in Beckton, east London, was effectively mothballed with no clear date for its resurrection.

Thames Water has long touted the plant as one of its key measures to protect Londoners in case of drought, and it has been included in local authorities’ resilience plans. 

But should an official drought be declared this year, the plant will not be fired up as it undergoes what the water company said was “necessary planned work”. There are now questions over whether it has ever been fully operational since it was built. 

The water industry is already under pressure over its record on leaks, which amount to 2.4 billion litres a year, even as customers are asked to cut down to help the environment. It now faces more criticism that it is asking households to make up for its own failures. 

In the absence of the Beckton plant, Thames Water will have to lean more heavily on households to reduce their consumption. It has already asked bill-payers to let their lawns go brown and their cars stay dirty ahead of an expected hosepipe ban in the capital.

“Bill-payers will rightly question what value for money they have seen from the significant investment in this plant,” said Karen Gibbs, of the Consumer Council for Water.

Industry insiders say Thames Water gambled on placing the facility on an estuary, where it hoped to cut operation costs because the seawater, mixed with freshwater from the Thames, would be less salty and therefore less difficult to process. 

But the company failed to factor in that the water would be at different salinity levels at different times of day, rendering the plant unreliable for producing a steady supply of drinking water. 

Even when the plant is up and running, it will be producing less drinking water than Thames had originally envisaged. The plant was originally intended to produce around 150 million litres of water a day – enough for 900,000 Londoners – but was forced to revise the estimate down by a third earlier this year.

“This adjustment was made on the basis of experience and to avoid creating unrealistic expectations about the output that could be achieved over a sustained period,” said a Thames Water spokesman.

The impetus for the east London plant had been the 2012 London Olympics, which prompted concerns that an influx of people during the hot summer months could be disastrous for the city’s water supplies.

But the initial plans proposed in 2004 were blocked by Ken Livingstone, then the London Labour mayor, who argued that the plant was unsustainable and unnecessary - despite the city being in one the most water-stressed parts of the country.

When Boris Johnson became mayor in 2008, the plant was given the green light - with construction completed two years later.

Thames Water had initially planned four more, but there is little sign of plans for a new plant.

It is an experience replicated recently in Hampshire, where Southern Water was forced to drop plans for a desalination plant last year. The area will be the first in the UK to come under a hosepipe ban, which begins on Friday. 

The plant had been opposed by green groups, the environmentalist Chris Packham and Julian Lewis, the local Conservative MP.

South East water, which became the second water company to bring in a hosepipe ban this week, has included potential mobile desalination plants in its long-term drought plans, but does not intend to introduce them this year. 

The Thames Water saga is the latest in a long-running battle for Britain to develop the desalination technology common to hotter and drier countries in the Mediterranean and Middle East.

The technology, which converts briny water into drinking quality through reverse osmosis, will almost inevitably be needed in the UK as it faces a changing climate, said Martin Currie, who consulted on the project. “Eventually there probably will be more desalination plants, because that’s just the way it will go,” he added.

For water companies, the plants promise a solution to the increasing threat of drought without the need to resort to hosepipe bans and other restrictions. But getting them off the ground can be difficult, with opposition from green groups and politicians who object to the costs and huge energy consumption involved in the process.

“There are a few detailed schemes being proposed,” said Alistair Chisholm, of the Chartered Institution of Water and Environmental Management. “But they’re kind of a last resort.”

Critics argue that getting customers to reduce their water usage is a cheaper and greener way to tackle the UK’s looming water shortages. Regulators are also wary of giving the green light to projects over concerns that they may add to bill-payers’ costs.

Ofwat is understood to be looking into Thames Water’s management of the Beckton plant as questions were raised over whether it could have eased pressures this summer.

Elsewhere, the plants are uncontroversial. More than 170 countries have some form of desalination plant. These are concentrated in the Middle East but are also used in Germany and Spain.

“They pretty much have no option,” said Mr Chisholm. “The problem with desalination is it’s very energy intensive. And there can be local impacts on ecology because of the concentration of the effluent.”

But despite their drawbacks, desalination plants could be a vital back-up for a drier Britain, which is facing its rivers losing half of their water in the next 30 years. London, with its fast-growing population, faces the threat of long-running drought within 25 years.

“It's an emergency measure,” said Mr Chisholm. “And where you’ve got particularly water stressed areas, there’s obviously going to be more of a case for building that kind of kit.”

Even some green groups argue that the energy costs of desalination are a better alternative to draining our rivers dry.

“We’re in an emergency situation and we’ve got chalk streams drying up all around the Chilterns and north of London,” said Stuart Singleton-White, of the Angling Trust. “An emergency measure like this is better than sucking yet more water out of our rivers and our chalk aquifers.” 

CORRECTION: An earlier version of this article described Julian Lewis as a Labour MP. In fact, Dr Lewis is the Conservative MP for New Forest East.