Phase One: Grand Sluice

Since our last update in July, work has continued at Grand Sluice to prepare the structure for its full refurbishment. Our contractors Jackson Civil Engineering Ltd. have been carefully installing stop log liners. These are essential as they will allow us to safely dewater the channels when the main refurbishment begins.

Working with the tides on the downstream side has been particularly challenging. At low tide, the team can work on the bottom sections in dry conditions. But when the tide is higher, they need boats to install the liners.

Upstream, significant work has taken place on the apron. Many of the timbers here are thought to have been in place since the sluice was built, making them over 250 years old! They have worn down over time as sand and gravel has passed through the sluice. These are now being replaced with new oak timbers to create a strong and even surface.

As winter approaches, we will be pausing works at the sluice. This is a planned step to reduce flood risk and make sure the gates stay fully operational during wetter months. This approach follows best practice and was also used in the 1980's when the large timber tidal doors were refurbished. Pausing now also avoids the risk of costly delays if flooding were to force work to stop unexpectedly.

While the sluice works pause, the contractor’s compound near Boston Rowing Club will be made smaller. The site will still be used to support other works on the Lower Witham.

We expect to return to site in spring 2026 to continue the refurbishment. This will include replacing the gates. In the meantime, our project team will be finalising the detailed designs for these new gates, which will form the core of the main works.

A contractor installing stop log liners on on the downstream side of Grand Sluice.

Contractors working on the downstream side of Grand Sluice during low tide.