A new 5km flood alleviation scheme in Oxford will reduce the risk of flooding to local roads, rail infrastructure and essential services. Construction is set to start in 2027 and could take up to five years to complete.
New stream and lowered floodplain create space for excess water
The scheme will run from north of Botley Road to Kennington, reconnecting with the River Thames. It involves creating a new stream through a wetland corridor and lowering sections of the existing floodplain to increase capacity when water levels rise.
Currently farmland and floodplain meadow, the land will also feature new flood embankments, walls, culverts, bridges and flood gates. During high flows, water from the Seacourt, Bulstake and Hinksey streams will be diverted through the new channel and lowered floodplain areas.
Protecting transport infrastructure beyond the carriageway
The scheme passes beneath the A423 Kennington Railway Bridge on the Oxford Southern Bypass, protecting local roads and rail assets through flood risk management outside the highway boundary.
Flooding can close roads and restrict access. It can also leave highway teams dealing with damage and debris once waters recede. This project aims to lower flood water levels and reduce disruption rather than guarantee assets remain operational in every flood event.
This approach highlights how road resilience sometimes depends on managing water across wider catchments and floodplains rather than just investigating the road surface.
Environmental and economic benefits of the flood scheme
Alongside flood risk reduction, the scheme will create more than 20 hectares of wetland habitat and around 16 hectares of floodplain meadow. Removing Towles Mill weir will improve fish passage through Oxford’s waterways.
The Environment Agency estimates the project could prevent more than £1.8 billion in flood damage and disruption over its lifetime. This is a projection based on potential performance during future floods.
A partnership approach to flood and network resilience
The Environment Agency has appointed GRAHAM as the construction partner for this project. Support comes from Oxfordshire County Council, Oxford City Council, the University of Oxford, Thames Water and National Highways.
The scheme demonstrates the link between flood management and highway resilience. While engineering takes place mainly across fields and floodplains, its success will be measured by reduced disruption on roads and rail routes affected by rising river levels.
