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 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 Trust worked with Guildford Borough Council to put in an essential temporary repair to make sure 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 have been able to design a replacement structure, which reuses the materials in the current temporary weir as much as possible. 

Following this detailed understanding of the required works, we are delighted to have secured the expected funds for the replacement project, which includes both the weir and bridge.  

 

What happens next?

2025 will be spent gaining the necessary permissions and agreements required. We will be working through a variety of agencies to ensure that any flood risks posed by conducting this work are mitigated, as well as tendering for the construction phase of the project.  

Although it is our hope to be able to deliver the replacement works over the summer of 2026, there is an element of risk to this date as there are several factors to work through. There is also a very narrow 3-month window of opportunity to complete the works due to water levels. Even a small delay in securing permissions, or a change to the costs, would mean that the project is pushed back by an extended timeframe. 

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.