Drought means Exmoor's giant Wimbeball Lake could see water level hit new record low

WATER levels in Wimbleball Lake, on Exmoor, were this week heading for a new record low after this summer’s heatwaves and drought.

Despite some recent heavy rainfall, Wimbleball, which is one of South West Water’s (SWW)‘ big three’ strategic regional reservoirs, was only 21 per cent full in the week ending September 27.

It held 4,491 million litres against its capacity of 21,320 million litres and in percentage terms was the lowest of all but one of SWW’s 17 reservoirs.

Only Kennick, Tottiford, and Trenchford Reservoir on Dartmoor’s eastern edge was lower at 19 per cent, but it is 10 times smaller than Wimbleball with a capacity of only 2,011 Ml.

Wimbleball dropped three per cent on the previous week, and a similar fall in the next seven days would see it less than one per cent above its record low figure of 17.2 per cent, recorded in October, 2022.

Of SWW’s other two ‘big three’ reservoirs, Roadford was 41 per cent full and Colliford stood at 39 per cent.

A SWW spokesperson said: “Water from these three strategic reservoirs is shared between a lot of the smaller reservoirs, which is why making sure Colliford, Roadford, and Wimbleball are nice and full is so important.

“The dry summer of 2026 has meant river levels are very low, and reservoir levels are lower than normal.

“Even with some rainfall, water resources will take a while to recover.

“We are continuing to monitor our water resources closely, and we thank all our customers who have taken steps to reduce their water use over the summer.

“To help water supplies as they recover, and with extreme weather events becoming more likely, please continue to use water wisely.”

The spokesperson said Wimbleball’s level was lower than Colliford and Roadford because it was used to support water flow in the River Exe, which then allowed SWW to abstract from its Pynes and Allers water treatment works, near Exeter and Tiverton, respectively.

They said: “The dry weather has meant the River Exe has dropped below the threshold where we have to release water from Wimbleball.

“Colliford and Roadford also support abstraction from the rivers Fowey and Tamar, respectively.

“However, they have not dropped below the threshold as quickly as the Exe.

“Even when your local reservoir is brim full, we are encouraging everybody to use water wisely.

“We are continuing to monitor our water resources closely and we thank all our customers who have taken simple steps to reduce their water use over the warm and dry summer.

“Our teams are working hard to deliver major leakage reductions, which is already having an impact, and we are continuing to support customers with free water-saving devices and proactive water saving advice.

“By everybody joining us in using water wisely, we can continue to enjoy everything our beautiful region has to offer without putting unnecessary strain on supplies.”

People visiting Wimbleball are being advised to stay on paths and not walk down the steep banks as they may become stuck in mud.