Spending on waterways is ‘skewed’ towards CSOs

Government spending to improve the quality of river water is “skewed” towards tackling issues with combined sewer overflows (CSOs) despite them only accounting for 7% of pollution in waterways, an Environment Agency director has declared.

Helen Wakeman, deputy director of water at the Environment Agency, explained that while water and sewerage companies contribute around 36% of pollutants in waterways, CSOs were not the only cause that should be focussed on.

Other factors include treated effluent and pollution incidents, which combined with CSOs amount to around one-third of the pollutants in rivers. Other sources include surface water runoff from highways and other urban pollution as well as agriculture, which accounts for 40% of waterway pollution.

Wakeman said spending was “skewed” towards tackling CSOs despite only being one of several factors contributing to unclean waterways.

Speaking at the All Party Parliamentary Group meeting on water pollution, Wakeman urged stakeholders to look at the bigger picture of pollution sources when apportioning investment. From 2025-30, companies proposed spending more than £9 billion to meet new legislative requirements to reduce the number of spills from overflows. Under the government’s Storm overflow discharge reduction plan, around £60 billion has been forecast to be needed to meet targets stretching out to 2050.

She advocated for efforts to be made to tackle problems that require CSOs to be used upstream, to remove excess rain and surface water from entering the network and overwhelming assets.

On behalf of the sector, Water UK’s head of policy, Stuart Colville highlighted that legislation was yet to be passed in relation to the government’s plan to reduce discharges.

This includes enacting Schedule 3 to the Flood and Water Management Act, which would see sustainable drainage systems become a mandatory part of new developments. Schedule 3 is broadly supported by the industry as a way to keep surface water out of sewers. In Wales SUDs have been mandated since 2006.

Colville said that although progress has not been seen yet on Section 3 and legislation, Water UK did not recognise reluctance from government, but instead an overwhelming number of water issues to address made prioritisation more challenging.

He also supported the notion that water and sewerage companies should become statutory consultees for planning and development to end the automatic right of developers to connect to existing sewer networks.

Baroness McIntosh, who chairs the APPG, highlighted that aging networks, many of which lacked capacity, were being expected to handle ever-increasing flows of wastewater as new homes and developments are built without consideration of the networks.

Wakeman added that some water bodies would never again be “close to their natural state” as specified as a target in the 25-year Environment Plan. She suggested expectations should be managed to reflect centuries of urbanisation which have permanently altered watercourses such as reinforcing embankments and developing harbours.