Council uses planning powers to ensure sewage infrastructure keeps pace with new development

In response to serious capacity issues and rising concerns about sewage pollution, the Council made arrangements to include Grampian planning conditions for housing developments in areas where the existing sewage infrastructure is unable to cope. These conditions mean that new homes cannot be lived in until vital infrastructure upgrades have been completed and are operational. In each case, Thames Water has been consulted on the proposed developments and is aware of what upgrades are required. 

This approach is a direct response to delays and underinvestment in local wastewater infrastructure. The Council continues to press Thames Water to prioritise and deliver upgrades, while also working with national regulators Ofwat and the Environment Agency as well as local interest groups, to encourage more robust oversight and long-term investment. 

Cllr Lidia Arciszewska, Executive Member for Environment, said: 

“Our sewage network is under serious strain. Across West Oxfordshire, we have 20 sewage treatment works, and most of them are already operating beyond capacity, releasing raw sewage from their storm overflow tanks for thousands of hours each year, as well as untreated effluent during dry weather conditions, thus polluting our rivers and streams.  

“Additionally, the neglected sewer network is underperforming, many pumping stations are overloaded, while leaky pipes allow groundwater infiltration and surface water ingress, leading to notorious sewage spills into people’s gardens, streets, communal spaces and fields and backing up residents’ toilets in many areas.  

“That is unacceptable. By introducing Grampian conditions, we’re putting pressure on Thames Water to act to ensure failing systems are invested in, so that they can supply our residents with the necessary infrastructure. Everyone has a role to play in getting this right, and we’re doing everything we can to lead the way. Our priority is protecting the environment, standing up for our communities, and making sure new housing is delivered to the standard residents rightly expect. 

“That’s why we’re using every tool we have to encourage progress. We continue to work constructively with Thames Water, national regulators and local interest groups to push for the upgrades our communities need and deserve.” 

There are currently just under 1,000 homes across West Oxfordshire with planning permission or under construction that are not able to be occupied until the necessary infrastructure improvements have been secured. In each case, the necessary upgrades have been identified in liaison with Thames Water and a Grampian condition imposed to ensure these are secured prior to occupation.   

Cllr Hugo Ashton, Executive Member for Planning, added: 
“Our job is to make sure that new developments happen in a way that genuinely works for residents by ensuring they’re backed by the infrastructure and services people need to thrive. Communities rightly expect that new homes will come with proper sewage provision, and we agree.  

“These conditions are not about blocking housing, they’re about making sure new homes are liveable, sustainable, and properly connected. The delays we’re seeing are not caused by the Council, but by decades of underinvestment in wastewater infrastructure, an issue now holding back growth not just in West Oxfordshire, but across the country.” 

To support residents, developers, and local stakeholders, the Council has launched a dedicated webpage showing which developments are currently affected by Grampian conditions. The page also outlines how the Council is working to drive forward infrastructure delivery and ensure development is supported by the right services.