THAMES Water has released statistics which show the impact that record-breaking heat and severe lack of rain have had on water supplies across the south.
The company’s figures show that as of the end of July 2026, its London reservoir was at 74% of its storage capacity– lower than expected for this time of year.
Its Farmoor reservoir was at 92% of its storage capacity.
The rainfall within the Thames catchment throughout July constituted less than a millimetre, representing around 2% of the long-term average.
Since March, only about 40% of the long-term average rainfall has fallen.
Usage in London and Thames Valley was also at around 100 million litres more than normal per day through last month.
Thames Water remains at Drought Event Level 2, with a Temporary Use Ban (hosepipe ban) in place to help protect essential water supplies after coming into effect on July 23.
Since then, household demand has dropped more than 6% across Thames Valley and the Home Counties, and by around 3% in London.
Thames Water says that while groundwater levels were normal across most of the region by the end of last month, they had dropped below normal in Oxfordshire.
However river flows are below average, and soil is drier than average across the catchment.
The water supplier says that it has increased its leak response “significantly”; just over 1,000 leaks a week are seeing repair works– around 20% more than its usual rate.
Since the start of the 2026/27 financial year, Thames Water has found and fixed 30% more leaks than during the same period last year, and in July alone, teams found 88% more leaks than the same period last year.
It says the combination of prolonged dry weather, record demand and exceptionally dry ground conditions is increasing the likelihood of leaks and bursts across the network.
Martin Padley, Water Director at Thames Water, said: “We’re grateful to everyone who has already reduced their water use during this prolonged dry spell.
“The action customers are taking is making a real difference, helping to protect supplies for homes, businesses, local wildlife and the environment.
“With reservoir levels below where we would expect them to be for this time of year, and demand remaining high, we’re asking customers to keep going and continue using only what they need.
“Small changes, such as taking shorter showers, turning off taps and avoiding non-essential water use outdoors, all help reduce pressure on our network while our teams continue working around the clock to find and fix leaks.”
