Storm Overflows Improvement Plan

This plan sets out how we aim to address storm overflows.

A summary of our plan

We are committed to completely eliminating the discharge of untreated sewage, starting with storm overflows that discharge most frequently and those that have any environmental impact.

We are spending £150 million on storm overflows between 2020 and 2025 to reduce their impact on the environment, which we estimate will help us to achieve around a 25% reduction in the number of hours they operate for.

What does the plan involve?

Our aim is to address the problem of storm overflows by prioritising investment based on impact, while also delivering solutions at an affordable pace and in a way that has a low operational and embedded carbon footprint and maximises a multitude of benefits.

Our plan explains how we are:

  • increasing monitoring
  • increasing the separation of rainwater from foul water
  • increasing treatment capacity for combined sewage
  • increasing storage for combined sewage

Achieving these four goals will enable us to better deal with extreme weather conditions, which will help reduce the operation of storm overflows and protect our rivers and the sea.


is being invested to tackle storm overflows


reduction in the number of hours storm overflows operate by 2025


improvement projects to be completed between 2020-25

Storm Overflows Improvement Plan

Protecting our rivers and the sea

Find out more about what we are doing to reduce the operation of storm overflows throughout the area we serve.