Our work: Millbrook footbridge and tumbling bay weir

Guildford's much-loved weir

Millbrook tumbling bay weir lies in the very heart of Guildford town centre.

It is believed that there has been a weir on the site since the 12^th century, put there by mill owners to control the water levels in the 'pound' above in order to power their mill wheels. Today, the weir plays an important role in maintaining water levels along the River Wey.

How the structure works

The tumbling bay is a 'fixed crest' weir which allows water to tumble over from one level (or ‘pound’) to the next, giving the site its much loved rushing water sound. The structure also contains a set of three sluice gates which can be raised or lowered manually to adjust water levels. A footbridge previously ran over the weir channel, linking the footpath onto an island of green space, with the towpath continuing beyond. 

Water levels over the weir vary at different times of the year, from a slow trickle in summer to a constant torrent during wetter months, when up to two million litres or water per hour might cascade over the crest.

The collapse of the weir

In 2019 the structure, which dates back to the early 1900s, collapsed during a period of very high water. The National Trust worked with Guildford Borough Council to install an essential temporary repair to ensure that water levels could be maintained and to keep the navigations open to river users.

However, the footbridge is still closed, with a short detour in place for walkers to rejoin the towpath at Guildford Rowing Club or the Yvonne Arnaud Theatre.  

Please see towpath diversion maps below:

Map 1 From Millmead Lock                                   

Map 2 From Millbrook Weir (Millmead Lock side)                                   

Map 3 From Millbrook Weir

Map 4 Approaching Millmead from the south   

Map 5 Steps from the towpath, approaching Millmead from the south

Engineering options

In 2024 the National Trust tendered for, and commissioned, a feasibility study of Millbrook Weir. Over the drier summer months, a local specialist engineering firm conducted detailed geotechnical and structural investigations. Using the data from these surveys, our engineers designed a replacement structure, which reuses the materials in the current temporary weir as much as possible. 

Following this detailed understanding of the required works, the expected funds for the replacement project. were secured for both the weir and bridge.  

Throughout 2025 we worked with a variety of agencies and engineers on the plans, as well as tendering for the construction phase of the project. 

A detailed technical approach was drafted, designed by expert engineers and the relevant permissions secured to carry out the works.

Project delivery

The works to replace Millbrook weir and footbridge are on track and scheduled to start in summer 2026 as planned. We are pleased to confirm that we have the necessary approvals in place to proceed and have selected civil engineering contractor Knights Brown after a robust tendering process.

Residents and visitors in the area will start to see some changes on site in the coming weeks as a contractor’s site is set up at the council’s Millbrook car park (off the A281). This is essential to the weir repairs and reopening of the towpath over the Millbrook weir footbridge. We will keep the disruption to users of the navigation and the surrounding areas to a minimum and are in touch with local businesses and other groups. Throughout the works, the construction company will be working behind a temporary structure to dewater the weir, which will not affect the main navigation. The navigation will remain open as usual, with only short safety closures for specific activities e.g. when materials are being craned over the water.

There is a narrow 3-month window of opportunity to complete the works during this period of low water levels and there is an element of risk to this date as there are several factors to work through.

Thank you

We’d like to acknowledge the support of so many people locally who have expressed to us how much the bridge means to them and campaigned wholeheartedly for it to be reinstated. We share their passion for bringing back this much needed part of Guildford’s heritage. We appreciate their patience and hope for their continued support as we lead the next phase of the project, with a more certain future for Millbrook weir and bridge.

Ensuring equal access to green space, especially in an urban setting like Guildford, is a fundamental aim of the National Trust. We understand the importance of the riverside walks that the Wey Navigation offers to the community of Guildford, and the role that these areas play for wellbeing, socialising, exercise, leisure and enjoying nature. 

Thanks to your ongoing support, we are able to continue our vital conservation work and help to protect these special places.