Water levels on the river Thames in London have dropped low enough to allow the production of drinking water from mainland Britain’s only desalination plant – but it is currently out of service.

The £250 million Thames Gateway desalination plant in Beckton, east London, and remains mainland Britain’s only large-scale desalination plant. It was designed to provide additional drinking water to the capital during times of severe drought by turning brackish water from the Thames into potable water.

But despite the UK recording its driest July since records began in 1836 and suffering what government officials have described as an “exceptionally serious” drought, the plant has not been used at all this year.

Under , the firm is allowed to start using its desalination plant if a drought is declared and if water flow rates in the Thames drop below 3000 megalitres per day (Ml/d).

A drought was declared in England on 29 July 2026, and data obtained by New Scientist suggests water flow rates at Teddington in south-west London, the lowest point of the freshwater Thames, have been well below the 3000 Ml/d mark for weeks.

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In fact, the current rates are around 220 Ml/d, below even the target river flow threshold for Teddington of 300 Ml/d during the current drought. Normally, the target flow rate for the river is 800 Ml/d, to protect the river’s ecology and surrounding environment from over-abstraction by Thames Water.

Under normal circumstances, the current situation would allow Thames Water to start producing drinking water from the Beckton plant, to relieve pressure on other water sources. The Thames Gateway plant is capable of providing up to 100 Ml/d of water, about 4 per cent of the daily volume of drinking water supplied by Thames Water.

But the desalination plant has been beset with technical problems and is currently out of supply, according to Thames Water. Its 2027 draft drought plan published earlier this year reports that work is under way to replace damaged equipment, including the plant’s membranes, which act as filters for fresh water.

The plant has only ever run five times, , delivering the equivalent of seven days’ worth of drinking water supplies to London. It has not been used at all this year, despite the worsening drought. Thames Water’s drought plan suggests the plant would take four to six weeks to ramp up to full capacity.

A spokesperson for Thames Water said the firm was working to ready the plant for operations later this year. They said in a statement: “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.”

Data released by the Environment Agency this month confirmed that July 2026 was the driest July for the Thames area since records began in 1871, with the region receiving just 1 millimetre of rainfall for the entire month. Parts of the river Thames are suffering exceptionally low flows, which can lead to low oxygen levels and deteriorating river health.

The problems at the Beckton desalination plant come as other water companies look to build desalination plants across England, in a bid to shore up water supplies as climate change brings more frequent and intense droughts to the country.

Anglian Water is developing plans for two plants in Norfolk and Lincolnshire, using seawater from the North Sea. Meanwhile, South West Water is also drawing up plans for a desalination plant in Par, Cornwall, to help the county cope with the increased water demands during the busy summer months.

Summer 2026 is likely to be the warmest on record in the UK, with repeated searing heatwaves and a severe drought affecting much of the country. In southern England in particular, the landscape is parched and crispy, rivers and reservoirs are running low, and trees are shedding their leaves in a stress response to the dry weather. Much of Europe is baking under similar conditions.

How much longer can we cope without rain? And how long will it take us to recover from such an unprecedented dry spell? With the help of experts from across water, agriculture and climate, we’ve answered your key questions below.

How bad is the drought?

Almost three-quarters of England is now in drought conditions after the driest July in almost two centuries, when barely any rain fell in many places. The National Drought Group – which includes public bodies, agricultural and environmental organisations – has described the situation as an “exceptionally serious” flash drought, driven by a combination of very high temperatures and exceptionally low rainfall over recent weeks.

It is taking a severe toll on the landscape. Almost 250 wildfires have been reported in biodiversity hotspots this year, wetlands and peatlands are drying out, and trees are dying. Some 22 per cent of rivers are at exceptionally low levels, including the Avon, Wye, Ely Ouse and Exe.

“The almost completely dry July is exceptionally unusual and add to that the heatwaves, the soils have dried very quickly and river flows have dropped very fast,” says at the UK Centre for Ecology and Hydrology.

How short of water are we?

The dry, hot weather over July and August has rapidly depleted rivers, reservoirs and underground aquifers, despite the wet winter England just experienced. Reservoir levels in England have fallen to 69 per cent – 11.6 per cent lower than what would be expected for this time of year. Reservoir storage in the country fell 16 per cent in July, the greatest reduction in raw storage for at least 30 years, the UK government said this week.

It is a sign of the impact of climate change, which is expected to bring drier, hotter summers to the UK. This year shows that even a wet winter isn’t enough to carry the UK through an extremely hot, dry summer. “Currently the situation is that we’re just simply using too much water,” says at the University of Oxford. “We’re not replenishing at the same speed as we’re using water.”

But great progress has been made in improving water storage, infrastructure and the industry’s response to drought in recent years, says at the Open University. This means the water industry is better equipped to deal with drought than it was in 1976, even though the weather has been hotter and drier for a longer period than 50 years ago. “It’s more severe than 1976 in terms of heatwaves and repetition of heatwaves, but the status of the water-supply system is currently not as bad as it was in 1976,” he says.

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How are trees, plants and wildlife coping?

You may have noticed the crunch of dry leaves underfoot in recent weeks. That’s a sign stressed trees are going through a “false autumn”, where they shed their leaves and even branches in an effort to keep their main stem alive. Some will not make it through – the 2022 heatwave killed 400 trees at Kew Gardens in London. Younger trees are at greater risk, as newly planted trees need 50 litres of water per week during the summer months for the first three years after planting.

Meanwhile, low river levels are causing algal blooms in rivers, and hard, dry soils make it impossible for animals such as badgers and hedgehogs to dig for food. Fierce wildfires have swept through nature reserves, destroying habitats and killing wildlife.

Unfortunately, this is the third drought in five years for England, and ecosystems are already stressed and weakened by these previous events. That makes it more difficult for them to recover from this extreme summer.

When will it next rain?

The intense heat of this week will give way to cooler temperatures next week, according to the Met Office, the UK’s national weather service. Although temperatures are expected to be closer to average for this time of year, whether rain will fall in the areas under the most stress is far from certain. Forecasters have struggled this year to accurately forecast rain, with wet weather often failing to materialise.

Even if rain showers do arrive next week, it is unlikely to be enough to alleviate the drought, in a blog post this week. There’s also the not insignificant risk of a dry, hot September, with long-term forecasts currently favouring drier weather.

What happens if there’s no rain the next few weeks?

Water companies will prioritise maintaining household water supplies above all else, but other sectors, such as agriculture or commercial businesses, are likely to face increasingly tight restrictions over the coming weeks if the drought continues.

Hosepipe bans – known as temporary use bans – are already in place across much of the country and can reduce consumption by 5 to 10 per cent. At least one water company – Southern Water – has applied to the government for a drought order. That would give it powers to introduce a non-essential use ban that restricts certain commercial activities such as car washing, window cleaning and watering commercial premises. Other water companies have signalled they will follow suit if the situation doesn’t improve in the next few weeks. Water companies can also apply to take more water from rivers and aquifers to maintain supply, but this threatens wildlife and habitats.

The next step up is an emergency drought order, which needs to be approved by the environment secretary. This would allow water companies to impose rota cuts on household and commercial customers, as happened in 1976 when mains water to households was curtailed and standpipes were installed in streets.

However, this is highly unlikely to happen this year, says Collins, as water companies would deploy all other possible measures first. “Public water supply is always the priority, no matter what happens,” he says.

Is there a threat to food supply?

Farmers are already warning that yields of some crops will be significantly lower than normal this summer because of the drought. Wheat yields are expected to be down 14 per cent compared with the average, and potato yields are expected to be 10 to 15 per cent lower than average. Meanwhile, harvests of fruits such as apples are also expected to be lower than usual, and the fruit smaller in size. The Energy and Climate Intelligence Unit, a think tank, it could be the worst harvest on record for UK farmers, with drought-related yield losses potentially costing arable farmers £390 million in lost revenue.

The situation is made worse by the fact that much of Europe is also sweltering under hot, dry conditions, meaning food production across the continent is also likely to fall this year. Together, that is likely to push food prices up for consumers into the autumn, particularly for fruit.

Farmers in England are struggling to adapt to heat and drought extremes because the weather is still so changeable, says at Rothamsted Research. “We’re not like the Mediterranean, where you get predictably hot, dry summers every year,” he says. Paul’s research is focused on breeding crops and developing treatments to boost yields in both wet and dry conditions. “The solution isn’t to breed drought-tolerant crops that only do well under droughts,” he says.

What could water companies be doing to save water?

Over the longer term, England needs to get better at storing water from its wet winters to tide it over during the summer months. This means building new reservoirs – a costly, time-consuming endeavour – and expanding water-transfer schemes to transport water from wet regions to dry ones. Even more radical plans are being explored, from building desalination plants to artificially injecting more water into underground aquifers during winter months.

The Environment Agency predicts there could be a shortfall of 5 billion litres per day in water supply across England by 2050 if more isn’t done to limit demand and increase supply.

How long will it take for the drought to end?

In the eyes of the public, a few days of rain is enough for the drought to be over. But it takes landscapes and wildlife far longer to recover from such an extreme dry spell. The flash drought that developed last year across England only ended in autumn when weeks of above-average rainfall arrived.

Hydrologists will be watching closely for a wet autumn and winter this year, which will help to recharge rivers and groundwater ahead of next summer. A strong El Niño now underway in the Pacific Ocean could increase the chances of a wetter start to winter for the UK, although El Niño’s influence on UK weather is indirect and difficult to predict.

However, a dry winter could leave the UK vulnerable. “A dry winter would make us worried about next spring and summer,” says Watts. That would put the country in a vulnerable position and raise the threat of emergency drought orders being introduced.

Iran is experiencing a drought so intense that the country’s president has said the capital city, Tehran, might have to be evacuated. In an attempt to bring rain, aircraft began a cloud-seeding operation on 15 November that is planned to last through the traditional rainy season until May. But experts caution that this technique is challenging and unlikely on its own to make a major dent in the water crisis.

How bad is the drought in Iran?

Rainfall across Iran is 85 per cent below average, and Tehran has received only 1 millimetre of rain this year. Reservoirs in the capital and in nearby regions are in a “worrying state”, officials have said, with water capacity under 5 per cent at 32 dams. Satellite images some have dried up entirely.

Tehran residents have reportedly reduced water consumption by about 10 per cent, but that isn’t enough, officials say. Water pressure has been reduced at night, and authorities are planning to fine households and businesses that consume excessive water. If rainfall doesn’t pick up by December, the 14 million people who live in Tehran could have to start evacuating, the president has said.

What caused the drought?

Experts the climate crisis has contributed to the drought, which has already lasted for five years. Iran is experiencing its driest autumn in 50 years, and Tehran, which often gets snow in November, is seeing temperatures of 15°C (59°F) or more.

But poor management is the main cause of what a former Department of Environment official, calls Iran’s “water bankruptcy”. The government has massively expanded agriculture in dry areas, overtaxing water resources. Half a million illegal wells, many of them drilled by desperate farmers, have depleted the groundwater.

What is cloud seeding?

Cloud seeding was developed in the 1940s by scientists including Bernard Vonnegut, brother of the novelist Kurt Vonnegut. It involves dispersing particles that encourage the suspended water droplets in clouds to fall as rain. Although some have sprayed salt into low-lying clouds, many have focused on spreading chemicals, most commonly silver iodide, into higher, mixed-phase clouds. The supercooled liquid water droplets freeze on contact with this crystalline compound, forming ice crystals that grow heavy and fall as snow or rain.

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It is often hard to know how much rain or snowfall would have occurred without the cloud seeding, though.

“The effects are very difficult to show because of the large natural variability of clouds,” says at University Clermont Auvergne in France. “You look outside, you have a cloud field, and there are clouds that rain, and others don’t rain.”

An experiment in 2014 comparing two mountain ranges in Wyoming found that cloud seeding could strengthen precipitation by .

Can it solve the drought?

Iran, which previously accused Israel and the United Arab Emirates of stealing its rain through cloud seeding, now has its own programme that involves seeding agents from cargo planes, drones and , a term that typically refers to smoke furnaces on high mountains.

It said it seeded clouds on 15 November in the basin around Lake Urmia, which, over two decades, has dried up into a salt plain littered with rusty boats. Areas west of the lake received up to 2.7 centimetres of rain early the next morning, according to a run by the University of California, Irvine.

For a cloud-seeding campaign to replenish reservoirs, however, the clouds must contain a lot of water. That kind of cloud may be hard to find in arid Iran, where there aren’t many large water bodies to evaporate moisture into the air.

“Cloud seeding is often much more difficult during a drought because the atmosphere is so dry, and any clouds that are present may not have sufficient moisture,” says Karen Howard, a scientist at the US Government Accountability Office.

But masses of rain clouds have blown into Iran from the Black Sea in the past three days, even causing flooding in western provinces, including Ilam and Kurdistan, on 16 November.

Cloud seeding will be able to at least “squeeze out a few more drops” from weather systems like this, says at the University of Arizona. “It’s not going to lead to extreme things like flooding or solving widespread drought,” he says. “But it can help a little bit.”

Unsustainable irrigation and drought have emptied nearly all of the Aral Sea’s water since the 1960s, causing changes extending all the way down to Earth’s upper mantle, the layer beneath the planet’s crust. This is probably the deepest recorded example of human activity changing the solid inner Earth.

“To do something that would affect the [upper mantle] is like, whoa,” says at the University of Southern California. “It’s showing you how potent we are at changing the environment.”

The Aral Sea in central Asia was once one of the world’s largest bodies of water, covering almost 70,000 square kilometres. But Soviet irrigation programmes starting in the 1960s, as well as later droughts, emptied the sea. By 2018, it had shrunk by almost 90 per cent and lost around 1000 cubic kilometres of water.

at Peking University in China became curious about the Aral Sea after reading a book about the consequences of this environmental disaster on Earth’s surface. “I realised that such a huge mass change would stimulate the response of the deep Earth,” he says.

He and his colleagues, including Barbot, used satellite measurements to track subtle changes in the emptied sea’s elevation between 2016 and 2020. Although much of the sea’s water disappeared decades ago, they found the uplift is ongoing, with the surface rising by around 7 millimetres per year on average.

They then used a model of the crust and mantle beneath the Aral Sea to test what changes deep below would lead to this observed pattern of uplift. “We find that the observations are completely compatible with a deep response to this change,” says Barbot.

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As the weight of water was removed, the shallower crust responded first, according to their model, by unbending. This prompted a response at depths as far as 190 kilometres below the surface, as viscous rocks in the upper mantle crept in to fill the void. “The unbending creates space, and the rocks want to flow into it,” says Barbot. This delayed response in a hot, weak region of the mantle called the asthenosphere is why the uplift is ongoing, even decades after the water was removed, he says.

Rebound in the upper mantle is known to occur after other large changes in mass at the surface, such as the advance and retreat of glaciers, says at the University of California, Berkeley. But the response to the draining of the Aral Sea may well be the deepest example of a human-caused change in the solid Earth, he says.

Other changes caused by humans, such as filling large reservoirs or pumping groundwater, have also caused rebound, says at Virginia Tech. But the wide range of the Aral Sea means the effects of emptying it are likely to run deeper, he says.

In addition to illustrating the sheer scale of human activity, the uplift beneath the Aral Sea offers an unusual opportunity to estimate small differences in the viscosity of the mantle, particularly where it lies beneath the interior of a continent, says Bürgmann. “Knowing how that layer right under continents behaves is really important for people who try to understand plate tectonics.”

Severe droughts that persist for years have grown hotter, drier and larger since the 1980s. These long-lasting droughts – some of which are extreme enough to be classified as “megadroughts” – can be especially devastating to agriculture and ecosystems.

Rising temperatures linked to climate change have increased the risk of drought because warmer air can hold more moisture, boosting evaporation from the land. Combined with changing precipitation patterns that lead to less rain, this can exacerbate and lengthen periods of drought – as witnessed in the recent worst-in-a-millennium megadroughts in parts of North and South America.

at the Swiss Federal Institute for Forest, Snow and Landscape Research and his colleagues identified more than 13,000 droughts that lasted at least two years between 1980 and 2018 to reveal long-term trends. They found that, since the 1980s, the most severe multi-year droughts have become even drier and hotter.

The droughts have also affected a larger part of the globe, with the area affected by the 500 most severe drought events underway in any given year expanding by about 50,000 square kilometres annually. “That’s an area bigger than Switzerland,” says Karger.

Satellite images of greenness in the areas affected by drought also showed some ecosystems became browner, indicating the drier conditions were having an effect. The most dramatic shift was in temperate grasslands, which are more sensitive to changes in water availability, while tropical and boreal forests showed a smaller response.

The researchers did not do a formal analysis to define how much human-caused climate change has contributed to the trend, but the patterns are consistent with what researchers expect to see with rising temperatures, says at Columbia University in New York, who was not involved with the research.

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The work highlights how long-term drought can have consequences just as severe as climate disasters like destructive wildfires or powerful hurricanes, says Cook. “For both people and ecosystems, the cumulative impact of droughts is really what matters.”

Large portions of the Amazon rainforest are threatened by the compounding effects of drought, heat and deforestation, which could push some ecosystems past a tipping point. But the potential for a wider scale collapse remains uncertain.

“The forest as a whole is very resilient, and that’s why we still have a window to act,” says at the Federal University of Santa Catarina in Brazil.

Researchers have warned for decades that rising temperatures and deforestation could push the Amazon past a tipping point beyond which runaway feedbacks lead to a rapid transition from forest to savannah. Drought and heat driven by the ongoing El Niño and warming with climate change have again raised the alarm.

But climate and ecological models representing the enormous complexity of the Amazon disagree on when or where such a tipping point might occur.

To understand which regions of the Amazon are most acutely at risk, Hirota and her colleagues looked at satellite data to assess how several different ecosystem stressors might change in the coming decades. These included temperature during the dry season, exposure to drought and the risk of fire and deforestation.

They found 10 per cent of the Amazon basin is at risk of being exposed to at least two of these stressors by 2050, and therefore has a higher potential of transitioning to degraded forest or to a savannah-like ecosystem. As much as 47 per cent of the basin is predicted to be exposed to at least one stressor – meaning it is also in some danger.

“Some forests are going to be lost because of ongoing changes, but there are things we can do to avoid going to 47 per cent,” says Hirota. She points out most of the forest not exposed to stressors is located inside protected areas and , which are associated with low rates of deforestation. Deforestation rates in Brazil have also plummeted under the administration of president Luiz Inácio Lula da Silva, although they have of the Amazon.

at the University of Leeds in the UK says the study is a strong survey of the different threats facing the Amazon. However, he says it doesn’t resolve the differences between models projecting a potential tipping point.

For instance, models project some of the negative effects of warming may be offset by increasing concentrations of atmospheric CO2, which should boost plant growth. But other factors, like nutrient and water availability, vary widely across the basin and influence the strength of this effect, leading to considerable uncertainty for modelling the future of the Amazon.

“For such an important ecosystem, that’s quite a scary place to be,” he says.