Council leader calls for answers on emergency discharge from the proposed Abingdon reservoir
Published 22 December 2025
The Leader of South Oxfordshire District Council, Cllr Maggie Filipova-Rivers, has this week written to the Secretary of State for Environment, Food and Rural Affairs, in relation to Thames Water’s Water Resource Management Plan (WRMP) and the South East Strategic Reservoir (SESRO) near Abingdon.
Cllr Filipova-Rivers has called for clarity regarding how emergency discharge from the proposed Abingdon reservoir will be managed. She is also calling for a firm commitment to providing the resources necessary to deal with any such discharge before the government considers any further consent to the project.
Under the proposals, Thames Water will have an emergency discharge facility in place which will include the ability to empty the reservoir at a rate of 1 metre of height per day, possibly over a period of 3 to 4 weeks. This would result in large volumes of water streaming back into the Thames just to the south of Abingdon, thereby, significantly increasing the flow of the river.
The big concern is that the knock on impact of this discharge could potentially threaten surrounding residences, businesses and wildlife.
In the letter, Cllr Filipova-Rivers raised concerns on the impact of this arrangement on the surrounding area: “The council is gravely concerned that such a discharge could cause havoc along the Thames, endangering lives, homes, businesses, communities and the environment. Under current regulations, Thames Water does not, however, need to have a plan in place for emergency discharge before they have constructed the proposed reservoir (in fact they only need such a plan once they propose to fill it).
“Dealing with the impacts of an incident caused by a discharge from the SESRO will fall to the successor authority/authorities of Oxfordshire. As the local emergency planning authority, they will be responsible for safely managing any potential crisis and will, consequently, have to make difficult decisions regarding which lives, homes, communities and businesses will be prioritised if the worst should happen.
“We are requesting the government makes a commitment to providing the resources necessary to deal with any such discharge before consideration is given to any Development Consent Order.”
The letter follows a debate on the topic at the full council meeting on Thursday 11 December – where a motion was raised by Councillor Barlow expressing concerns about the proposed reservoir’s Emergency Discharge facility. The motion and subsequent member discussions highlighted how the discharge could cause havoc along the Thames, endangering life, residences, businesses, wildlife and the environment, with no requirement for the reservoir operator to have an emergency plan before building the reservoir, only before filling it.
A resident of Culham also raised a question at council on the same topic, expressing deep concerns about the impact on their home which is “300 m from the point on the Thames directly opposite where the outfall tunnel will come out. Probably the nearest or one of the nearest homes to this” and for another 13 homes directly on the ‘red line’ boundary of the land that Thames Water have identified as being affected by the outfall tunnel.
Alongside the issue of Emergency Discharge and the potential for increased flood risk in local watercourses, concerns have also been raised recently around the size of the proposed scheme, its environmental impact, carbon costs and significant (growing) financial costs – which has soared to more than double the original estimate.
Thames Water is currently running a public consultation on the proposed South East Strategic Reservoir Option (SESRO), until 13 January 2026.
The feedback Thames Water gathers will inform their Development Consent Order (DCO) application to the government, which they expect to submit in autumn 2026.
People can have their say on Thames Water’s consultation webpages and read more about the proposals.
