Almost 100,000 homes in Sussex face having their taps turned off this winter if the region does not see heavy rainfall in the coming months.
South East Water (SEW) has warned the Government that there is a “realistic threat of a serious deficiency in supply” in an area that includes the major towns of Burgess Hill, Haywards Heath and East Grinstead.
The firm has submitted an application for a drought permit to allow it to conserve water in Ardingly Reservoir, which has fallen close to critical levels due to the exceptionally dry weather and successive heatwaves this summer.
Without this, about 95,000 homes could require “rota cuts and standpipes” if the region does not experience significant rain in the coming months, South East Water warned the Environment Agency.
If granted, there would be a temporary relaxation of the environmental rules that dictate SEW release water from the reservoir to maintain levels in the River Ouse.
Worst drought since 1976
An analysis of 155 years of rainfall data by SEW found 2026 was the second driest summer in the River Ouse catchment, surpassed only by 1976.
The summer of 1976 saw widespread water shortages and restrictions across England, including the use of standpipes in some areas.
Britain has not experienced such severe restrictions since that year. However, the latest documents from SEW show some areas are now coming close.
Much of England and all of Wales are currently in drought. While most areas have experienced unsettled weather in recent weeks, far more rainfall is needed to reverse the impacts of the dry summer.
SEW has said Ardingly Reservoir could enter “red level” drought status within the coming weeks even if Sussex receives its average level of rainfall. As of Friday the reservoir was at 34.8 per cent total capacity.
“Red” is the final level before emergency measures such as standpipes are introduced. It means water companies must take all other action possible to avoid this scenario, such as further restrictions on businesses.
If the region receives less than 60 per cent of its average rainfall over the coming months, Ardingly will remain at red level for the rest of this year, and could enter an “emergency storage” situation by the end of September, South East Water said.
In a “worst case scenario” of the region receiving less than 40 per cent of its average rainfall, the reservoir will remain at red level into spring next year and would also enter an ‘emergency storage’ situation around the end of this month, SEW said.
The affected area of Sussex has received 43 per cent of its average rainfall since March this year, meaning this “worst case scenario” would be a continuation of what has seen seen.
Dry fields in the area surrounding Ardinly Reservoir (Photo: Carlos Jasso/Reuters)
Fish deaths and ‘sewage fungus’
It is now up to the Environment Agency to determine whether South East Water should be granted permission to reduce releases from the reservoir into the Ouse.
The company acknowledges doing so will trigger environmental impacts on the river including fish deaths and “increased growth of algae and sewage fungus”.
However, it argues that doing nothing would also have an adverse impact on the Ouse and that conserving water in the reservoir is the best option for customers and the environment.
Water firms ‘not doing enough to fix leaks’
Water companies have been criticised for not doing enough to make their regions resilient to drought, for example by fixing leaks or building more reservoirs.
In its drought permit application, SEW states that its leakage levels are currently 15.5 per cent above target and have become worse this summer as dry soil has caused more burst pipes.
Towns across Sussex and Kent have experienced multiple water cuts in recent years due to failures in SEW’s network.
A damning report by MPs on the Environment, Food and Rural Affairs Committee, published in April, described the company’s previous leadership team and board as a “unaccountable clique”.
A spokesperson for South East Water said: “We applied to the Environment Agency for a drought permit to help manage the water resource situation in Sussex.
“The permit was applied for as we experienced less than half of the expected rainfall between March and August 2026 in our Sussex region, which is where we have two surface water storage reservoirs. This has resulted in the water levels in both reservoirs falling to a low level, particularly Ardingly Reservoir.
A spokesperson for the Environment Agency said: “The drought permitting process balances the needs of local water users with important environmental protections.
“We expect water companies to follow drought plans and apply for permits in good time to secure supplies for their customers and ensure that appropriate mitigations are in place to protect the environment.”