Construction group Graham has been appointed by the Environment Agency to deliver a £220mn flood defence scheme in Oxford, one of England’s largest projects designed to protect communities from rising flood risk.
The Oxford Flood Alleviation Scheme will create a 5km stream and wetland corridor west of the city centre, running from north of Botley Road to Kennington before rejoining the River Thames.
The Environment Agency says the project will protect all properties in Oxford currently considered at risk of river flooding, alongside infrastructure including railway lines, roads, utilities and broadband networks.
Construction is expected to begin in 2027 and take up to five years.
The project’s estimated cost has increased significantly. When Oxfordshire County Council granted planning permission in 2024, the scheme was valued at about £176mn, compared with the £220mn figure attached to Graham’s appointment.
The work will involve lowering parts of the existing floodplain and constructing embankments, walls, culverts, bridges and flood gates. During periods of high water, excess flows will be directed from the Seacourt, Bulstake and Hinksey streams into the new channel and surrounding floodplain, reducing pressure on the Thames.
Graham said the scheme was expected to prevent more than £1.8bn of flood damage and disruption over its lifetime.
“This is an extremely important project, given Oxford has lived with the threat of serious flooding for generations,” said Alastair Lewis, contracts director at Graham. “The vital piece of infrastructure will tackle the flood risk directly in a way that works with the landscape rather than against it.”
The project will also create more than 20 hectares of wetland habitat and about 16 hectares of floodplain meadow. The removal of Towles Mill weir is intended to allow fish to move through Oxford’s waterways for the first time in more than a century.
However, the scheme has faced environmental opposition. Oxford Preservation Trust has raised concerns about its impact on Hinksey Meadow and rare grassland, while local campaigners have criticised tree removal, construction traffic and development within the Green Belt.
Environment Agency project director Robbie Williams said the scheme would give Oxford communities “peace of mind from the threat of flooding, for decades to come” while leaving a lasting environmental legacy.
