Overview

June 2025 Update

We have re-entered the sluice channel to carry out works throughout the summer. We installed temporary pumps and pipes around the sluice to manage river flows while the old sluice gate was removed.
Fortunately, due to the dry weather, these have had little use and some have been removed. Now that the old sluice gate has been removed, we have installed a large flume pipe through the sluice to carry the summer river flows. When the river flows are low enough during the working week, a section of the flume is removed to give better working access, and the section reinstated for the non-working  weekends.

With the old sluice gate removed, we are removing a section of the sluice bed in preparation for installing a new floor to support the new gates. The channel bed that will be removed has been cut into sections ready for removal, prior to breaking out (shown in images below).

Above: The penstock to control water flows through the flume pipe

Above: The old channel being broken out and removed

Above: The flume pipe through the sluice carrying summer river flows as  necessary

Project Background

The waterways in the Lower Lee valley include the River Lee Navigation, Old River Lea, and the Lee Flood Relief Channel (LFRC). The LFRC was built between 1949 and 1977 and is designed to carry flood water to reduce the likelihood of flooding in the Lower Lee valley. A system of weirs, gates and sluices control water levels in the LFRC. These maintain water levels for water supply, navigation, amenity and environmental purposes while allowing flood flows to pass during storm events.

Stanstead Sluice is a major flood control structure within the LFRC and is located close to the villages of Stanstead Abbotts and St Margarets. It directly reduces the flood risk to 83 properties and contributes benefitting many more as part of the LFRC system. As well as managing flood risk the sluice maintains water levels in the River Lee Navigation.

Above: Stanstead Sluice before works began

What we are doing

We are replacing the sluice gate and improving the operating equipment at Stanstead Sluice as the existing ones are now reaching the end of their working life after over 45 years of service. A failure of Stanstead Sluice would result in increased flood risk and loss of control of upstream water levels. The existing single sluice gate will be replaced with two narrower gates.

These improvements will maintain the conveyance of storm flood flows through the structure, sustain the current level of flood management and maintain the ability to control upstream water levels for navigation, water supply, amenity and environmental needs.

The existing sluice is a barrier to the free passage of fish and eels migrating up the river. As part of this project, new fish and eel passes will be constructed to enable the free passage of fish and eels around the sluice and up to Hardmead Sluice where more fish and eel passes have already been installed. This will help increase the length of watercourses these species can migrate along, extending their range and improving the aquatic biodiversity of the watercourses.

How will the works affect me?

During the works, you may notice additional temporary construction noise during the working week.

Construction vehicles will enter the site using the access track from Hollycross Road, and then along the riverside trackway towards Stanstead Sluice. Unrestricted access will be required at all times.

We recognise that the trackway is well used by the public. We have limited the speed of construction traffic appropriately to enable continued quiet recreational use of the path and presence of the adjacent nature reserve.

Public Rights of Way will not be impacted.

Location of Stanstead Sluice and our access route (purple dotted line)