13. Eel Passage at Nazeing Marsh

Theme: Ecology and morphology


  • Enable fish passage throughout the catchment

Project description

A small concrete weir was notched to enable eel migration in the Lower Lea catchment.

The project was delivered in 2018 as part of the Slimy Wrigglers action plan, aiming to make the Lower Lea fully permeable to migrating eels.

A small brook running between Holyfield Lake and Nazeing Marsh, was identified as being suitable to support eel migration, linking to a previous project to install eel passes at Holyfield Weir enabling their migration into the lake.

Notching the weir on the small brook opened up 1.4km of channel, bypassing the Kiora Radial Gates at the top of Holyfield Lake – which was the next impasse to migration – and connecting into the next wetland complex at Nazeing.

Project lead: Herts & Middlesex Wildlife Trust
Project partners: Environment Agency, Lee Valley Regional Park
Project start: 2018
Project end: 2018

Design by LTD Design Consultants and build by Garganey Consulting.