Extract from the Environment Agency update (May 2026)
Background
In late autumn 2024, project sponsors the Environment Agency and Surrey County Council commissioned a mid-project review of the River Thames Scheme (RTS). The review was to ensure that this nationally important infrastructure project (as determined by the Secretary of State in December 2020) remained efficient, cost-effective and aligned with long-term goals. It was also to ensure the project provides the flood risk benefits in a strong and sustainable manner.
During the review, we paused most activity not directly related to the review.
Review aims and conclusions
The mid-project review had two elements. Firstly, to assess whether the proposed solution of a new channel and weir improvements remains the best option in terms of cost-effectiveness and viability. The second was to examine whether organisationally the RTS team was set up in the best way to complete a project of this scale and complexity. The government’s Infrastructure Projects Authority (IPA), now the National Infrastructure and Service Transformation Authority, carried this out independently.
The review has now ended and has confirmed that channels with weir improvements is still the best option for reducing flood risk. This is excellent news and RTS will proceed on this basis with no changes required to the design of the flood defences.
The IPA highlighted some changes to how the project is being managed, to improve efficiency. The Environment Agency and Surrey County Council are currently working through and implementing these recommendations to ensure RTS has the best organisational structure and processes in place for remobilisation. This post-review ‘reset’ is ongoing.
At the same time, the RTS team is updating the RTS outline business case to ensure consistency with the new Defra partnership funding policy which became effective in April.
After May 2027, and as a result of the local government reorganisation programme, the Environment Agency will be working with West Surrey and East Surrey councils.
With any large-scale project such as RTS, it does take some time to carry out a wide-ranging review and assure the work that has been carried out. We understand the frustration felt by all those who have been impacted by flooding in the past and want to see RTS completed as soon as possible.
The EA source document can be found here