2. Frays and Colne weir

Aim: Improve wildlife corridors

Water body: River Colne, Frays River
Project description

Weir modifcation to provide fish passage. This site in Denham Country Park, on the border of Buckinghamshire and Hillingdon, hosts two weirs that are located in two separate channels known as the Colne & Frays Offtake Weirs. Both of the weirs are used as Environment Agency telemetry stations as well as controlling the flow between the Colne and Frays rivers. For this reason, they could not be altered in any way that migh impact their primary purpose. The design and  installation selected were: A) modular fed eel pass on the River Frays; B) Larinier fish pass with a separate channel for the modular fed eel pass.

Eel Passes were successfully installed, to allow eels to negotiate the weirs in both of these positions. Groundwork South worked in partnership with Affinity Water, Thames Water and The Environment Agency (with additional funding from Grundon) to resolve barriers to the migration of European Eels.

Find out more here: 

Denham Eel Pass Project

and here Denham Eel Passes Installed

Refer also to Project 30. Denham Weirs Eel Passage Improvements

Project lead: Environment Agency
Project partners: Buckinghamshire County Council, Uxbridge Rovers Angling & Conservation Society
Contact for more information: Phil Bellfield

Design by LTD Design Consultants and build by Garganey Consulting. From an original concept by the Herts and Middlesex Wildlife Trust.