Latest on the work at Brownshill Staunch

As many of you will have seen, our contractors have put up scaffolding, both upstream and downstream of the site. This will allow us to safely work on the site to remove the existing radial sluice gates and install their replacements.

We have already removed the existing sluice gate from the centre bay and our contractors are making final checks before the new gate is installed. Two of the three gates will then be fully commissioned into service prior to work commencing on the third gate later in the year.

Upstream view of Brownshill Staunch with staging in place

Brownshill Staunch centre bay with sluice gate removed

Brownshill Staunch - removed central sluice gate

Works update

As many of you will have seen, work at Brownshill Staunch continues at pace. Our contractors are onsite; welfare provision and a site office have all been set up and we have had the access road re-surfaced to make it safe and usable.

The recent dive survey showed more damage than expected to the structure. We are currently reviewing what additional works we need to undertake to deliver the project objectives and to meet the delivery timescales.

Footpath closure – diversion in place

As part of this project, we have applied for and been granted authority by Cambridgeshire County Council to temporarily close the footpath through the site. We did not take this decision lightly as we are aware of the disruption this will have caused however, the safety of walkers, our staff and contractors is our priority.

If you use this footpath, please ensure that the diversion is followed whilst the path is temporarily closed. Full details of the closure and the diversion can be found on the Causeway One network site: https://one.network/?tmi=GB45044850

Moderation Project update

We are progressing plans to maintain water levels for navigation at St Ives on the River Great Ouse, helping to meet our legal responsibilities and support the continued use of the river by boaters and other waterway users.

Why is this project needed?

The existing St Ives sluice structure contains seven moveable gates that help manage water levels upstream. As the structure ages, we need to identify the most sustainable and cost-effective way to continue maintaining the required navigation water levels in the future.

What options were considered?

A range of options was assessed, including:

• Continuing with maintenance only and making no major changes.
• Replacing all seven sluice gates with new gates.
• Installing a fixed crest weir within the existing structure.
• Installing a fixed crest weir downstream of the existing structure.
• Installing permanent stop logs while retaining some or all of the existing gates.

The assessment considered not only the initial construction costs but also the long-term costs of operating and maintaining the structure over its lifetime, as well as impacts on flood risk in the area.

Why is the chosen option being proposed?

Following a detailed assessment of options, a fixed weir (either at or downstream of the site of the existing structure) has been identified as the preferred option, subject to the necessary approvals and assurance processes.

Fixed weirs are a proven and widely used method of managing water levels. Unlike a gated sluice, a fixed weir operates passively and does not rely on moving mechanical equipment.

This provides several benefits:

• Continued ability to maintain the statutory navigation water level.
• Ongoing support for flood risk management functions.
• Improved reliability.
• Reduced risk of mechanical failures.
• Lower long-term maintenance requirements.

The Environment Agency owns, maintains and operates 44 lock and weir complexes along the 135 miles of navigable non-tidal river Thames, and have similar assets and asset complexes on the river Great Ouse.

The fixed weir options show a resulting impact on flood depths but no increase in flood risk to properties. The greatest expected increase in flood depth is 50mm but with no change to flood extents and therefore, no additional properties are at risk of internal flooding. For further detail on the hydraulic modelling used to support this assessment please see the FAQs to the right of the page.

What happens next?

The cost to deliver this option is expected to be ~£4-5m so we must go through additional steps than previously anticipated to justify and gain approval to deliver the project. This means construction is now planned for 2027/28 instead of 2026/27.

As the project progresses, we will provide further information about the design, programme, and any impacts on navigation or local communities. Any temporary restrictions or changes required during construction would be communicated well in advance.

Works Update

Funding has been secured and contractors appointed to carry out improvement works at Brownshill Staunch Sluice during 2025–27. These works are due to be completed by March 2027.

We have now completed the surveys needed to plan the works and the replacement sluice gates are being prepared and painted for installation.

Programme

• Phase One (March to May 2026): Preparation work, including final gate inspections and preparations, design checks, surveys, and testing of equipment.
• Phase Two (May to March 2026-2027): Main works, replace the existing sluice gates, ropes, and associated equipment, followed by final testing.

What this means for you

• The public footpath over the sluice will need to be temporarily diverted during construction for safety.
• The lock will remain open, but there may be short interruptions while works are carried out.
• Advance notice of any restrictions will be shared.

These improvements will help ensure the sluice continues to operate safely and reliably. Thank you for your patience while the works take place.

Work continues on the St Ives Sluice as our contractors have just completed a thorough survey of both the gates and surrounding structures. This phase included underwater, ground level and aerial surveys and is an important step in determining the extent of the works required on the sluice, in advance of a decision about which solutions may or may not be feasible.

Environment Agency staff and contractors surveying part of the St Ives Sluices - 27 November 2025

Data from the survey is currently being compiled. It will provide a 3D model above and below the waterline which will be assessed with other condition surveys, hydraulic modelling and cost estimates to go into the business case for approval in late Spring 2026.

We have carried out repairs to the St Ives Sluices, bringing 3 gates back into automatic operation. These repairs will not provide long term resilience but should help maintain navigation levels during high flows over the coming winter period.

The remaining four gates continue to be isolated in the closed position to maintain statutory water levels for navigation.

Over the last couple of weeks, our incident response team have been deployed to St Ives Staunch Sluice to carry out temporary repairs due to a fault with one of the operational gates. As the situation stands, three of the seven gates are able to be operated. One of the three gates (gate 6) is operating automatically and, if required, the other two gates (gates 1 and 7) can be operated manually. The remaining four gates (gates 2, 3, 4, and 5) remain isolated in the closed position to maintain statutory water levels for navigation.

While we continue with the moderation project for St Ives sluices, we are currently awaiting the delivery of parts to hopefully bring the two manually operated gates back into automatic operation. These repairs would be temporary and given the condition of the structure, may not last long.

We are currently working hard to identify and develop cost-effective solution for the project. This involves approaching commercial partners for their costs and building a plan which provides the best solution allowed by the budget.

We will keep you informed of progress as the project develops.

Our bid for Capital Reconditioning funding over the next two financial years (2025/6 and 2026/7) has been approved.

This means we can start investigating what solution will recondition the structure so they can continue maintaining navigable river levels along this stretch of the River Great Ouse.

Our case for moderation funding to work on the St Ives Sluice has now been approved.

We can now start developing a cost effective plan that allows us to maintain navigable river levels along this stretch of the River Great Ouse.