United Utilities reveals reduction in storm overflow spills across Windermere and the North West

United Utilities’ ambitious £200 million investment plan to reduce spills across Windermere from storm overflows is moving at pace. 

 The water and wastewater company is set to confirm a reduction in the number and duration of storm overflow operations across the North West in 2024, when official figures are released, by the Environment Agency (EA) later this month. 

 In the Windermere catchment, the company's annual event duration monitoring (EDM) submission to the EA records a 28% reduction in spill duration - or 2,460 fewer hours of spills.

 At the same time, across the North West, the EDM submission records a 31% reduction in spill duration, or 205,236 fewer hours of spills, with the average number of spills from storm overflows estimated to fall by 20%.  That’s 19,720 fewer spills compared to the prior year. 

 The overall reduction in spills is despite 2024 being another extremely wet year recording the 8th wettest winter and 6th wettest spring on record.*

 In the Windermere catchment, early investment at Ambleside and Windermere wastewater treatment works is already delivering benefits to spill reduction. Last August, the company commissioned an additional 2.6 million litres of storage across the two sites – the equivalent of around 33,000 bathtubs or just over an Olympic-sized swimming pool. 

 The additional storage has increased the amount of storm water the sites can store and then return for full treatment, reducing the number of times the storm overflows need to operate during periods of heavy rainfall.

 Across Cumbria, United Utilities will spend more than £900 million over the next five years to reduce spills from 149 storm overflows, improving 219 kilometres of rivers across the county. This is part of a historic £13 billion infrastructure investment programme to make a stronger, greener, healthier North West.

 Matt Hemmings, Chief Operating Officer at United Utilities, said: “We totally understand concerns about storm overflows. That's why we have the largest overflow investment programme of all companies over the next five years. 

 "Our teams right across Cumbria and the North West are working extremely hard on projects such as increasing storage on sites, designing bespoke solutions such as sustainable drainage schemes and using the latest innovation to treat wastewater to even higher standards. This investment is making a real difference. 

"We are extremely ambitious about delivering change quickly, and we're making good progress as we embark on the largest ever investment programme in our infrastructure that will see the biggest overhaul of the region’s sewer network in a century."