UNITED Utilities has set out its 25-year plan to invest around £420 million in reducing sewer pollution across Cheshire.

Within this project, itself part of a wider £19 billion investment across the North West, the water company will be making improvements to 63 storm overflows in the county.

These overflows are the relief points which prevent sewers from backing up and flooding homes and businesses in heavy rain.

By 2030, United Utilities is aiming to reduce spills in the region by 50 per cent, with the goal of having each stormflow operate fewer than 10 times a year by 2050.

In and around Northwich, Winsford, Middlewich, Knutsford and Wilmslow, there are 12 overflows not currently meeting United Utilities' targets.

Which storm overflows will be improved?

  • Bexton Road CSO, between Knutsford and Tabley. Date all targets will be met: 2026.
  • Chester Road CSO, between Hartford and Gorstage. Date all targets will be met: 2050.
  • Holmes Chapel STW. Date all targets will be met: 2045.
  • Meadowbank/Bradford Road PS, Meadowbank, Winsford. Date all targets will be met: 2050.
  • Middlewich Road/Parkfield Road CSO, near Great Budworth. Date all targets will be met: 2029.
  • Nether Peover STW. Date all targets will be met: 2050.
  • Oakmere PS. Date all targets will be met: 2050.
  • Off Roddy Lane CSO, Crowton. Date all targets will be met: 2050.
  • The Carrs CSO, Wilmslow. Date all targets will be met: 2050.
  • Town Lane CSO, Mobberley. Date all targets will be met: 2029.
  • Wardle Bridge PS, Middlewich. Date all targets will be met: 2050.
  • Weaverham STW. Date all targets will be met: 2050.

What United Utilities say

Jo Harrison, asset management director at United Utilities, said: “Our purpose is very clear – we don’t just supply water, we also want to make the North West greener, stronger and healthier.

“The multi-billion-pound programme we are now embarking upon will see the biggest overhaul of the region’s sewer network in a century.

"Not only is this now enshrined in law, but it is also what our customers expect and it’s the right thing to do."

The company's Storm Overflow Reduction Plan will be in line with the new requirements of the Environment Act 2021, with work already started at some of the highest priority sites.

This week a dashboard has been published showing the locations of every storm overflow in the UK, with a timescale for achieving the target of 10 operations a year.

The first phase of the Storm Overflow Reduction Plan will take place up to 2030, and will involve £3 billion of improvements at 437 sites across the North West.

There are more than 2,200 storm overflows within the wastewater system across the North West region. Like the overflow on a bath, these are designed to prevent flooding and provide a route for water to take when sewers fill during heavy rain – automatically releasing a mixture of sewage and rainwater into the environment.

Since December 2023, every one of these sites is now monitored, allowing United Utilities to build a picture of how often each site operates and which should be tackled first.

Improvement work will be prioritised at the sites which operate most frequently or which discharge into bathing waters or environmentally sensitive locations.

Ms Harrison added: “We are making a fundamental change to the way our sewer system has been designed and change on this scale cannot happen overnight.

"We are re-plumbing our drainage systems, building storage tanks to increase the capacity, separating rainwater out of sewers, and harnessing the power of nature to treat storm water before it is returned to the environment.

"Work has already started, and people are going to see much more of this over the next 25 years."