Osney Bridge trunk mains replacement

This is a three-phase project to replace damaged water mains and reinforce Osney Bridge in Oxford. 

Following the damage in 2021, we installed a temporary pipe to maintain water supply to our customers.

Structural issues with the northern footpath have caused significant delays and complications. To replace the water mains safely, we must also reinforce the footpath. This requires a lane closure on Botley Road at Osney Bridge.

Network Rail’s expansion of Oxford Station means Botley Road is closed at the rail bridge. Due to delays with service diversions, the road did not reopen in October as planned and the closure will continue into 2026.

Our original plans would have required the full closure of Osney Bridge for us to do our work. To avoid cutting off residents and businesses, we would have needed to wait until Network Rail had finished working on the road.

Background

The Osney Bridge trunk water main was damaged by a third party in June 2021. Due to the location and severity of the damage a simple repair wasn’t possible, and this led to the project being classed as a major scheme. 

The project team discovered issues with the northern footpath, requiring structural and environmental surveys. To carry out the surveys, we had to close a section of the River Thames and get a flood risk assessment permit from the Environment Agency (EA). The EA then informed us that river closures at this location are only permitted between November and March.

In March 2022, we completed the required surveys. The results confirmed our concerns with the condition of the northern footpath structure. The council subsequently determined that due to our temporary water main inadvertently protecting the northern footpath from accidental vehicle loading, no further measures were needed at that time. 

This solution couldn't work long-term. So, in April 2022, it was agreed that the project would become a joint scheme between Thames Water and Oxfordshire County Council. Our aim was now to resolve the poor condition of the footpath structure, as well as the damaged water main.

The project team spent the next few months putting together an assessment report. This concluded that the footpath had never been safe for accidental vehicle loading. A far more complex solution was now needed to address the problem.

Three-phase project

Phase 1 – Enabling works

September 2024 to September 2025: The temporary pipe bridge foundations will be completed. The bridge and pipework will then be lifted into place, connected and commissioned.

Phase 2 – Main works

November 2024 to November 2026: Scaffolding will be installed to enclose the underneath of the bridge structure. Utility diversions will be put in place, and the water main will be replaced. The northern footpath will be repaired and upgraded.

Phase 3 – Decommission

October 2026 to January 2027: The temporary pipe bridge will be decommissioned and removed. The River Thames navigational path will be re-opened, site compound removed, the area reinstated and landscaped, and we will demobilise from the site.

How this may affect you

From March 2024 to November 2026, we’ll need to close the following on the city-bound north side of the bridge:

Pedestrian footpath
Cycle lane
The Thames towpath access to Osney Bridge with a diversion via the alleyway to Abbey Road
Carriageway:
- Following the reinstatement of 2-way traffic across Osney Bridge and reopening of Botley Road, we
  will still require occasional overnight lane closures on Osney Bridge. These are necessary to complete the final stages of the project, including the movement of materials and the commissioning of the new water main.  Prior notification will be provided of any overnight lane closures, which will be limited to between 8pm and 6am.

Further updates

As works progress we'll provide further updates to this webpage.