St Ives Eel Pass Project

The St Ives sluice and lock structure on the River Great Ouse forms a formidable and unpassable barrier for juvenile eel trying to move up the river systems to find suitable habitat, and with this is a key site for mitigation under the European eel and elver regulations. Aquatic Control Engineering are pleased to announce that early results from the large eel pass they installed at St Ives is already showing positive results, with many eel being recorded within weeks of the opening of the pass. ACE won the contract to design and install the eel pass The site has been the focus over several years of planning for improved eel and elver passage and through a regular and two-way dialogue between ACE and the EA, the preferred solution which has successfully been installed, was instigated. The size and location of the structure made the design of the eel pass a challenge. This site, the FCRM function of the structure, restricted the options available and the final design resulted in a 65 metre long underground eel pass, running through a private garden. One of the major issues that the team had to confront was how to deal with the myriad of plumbing and services positioned on the proposed eel pass route. While this proved to be challenging, the experience of the ACE team meant that problems where quickly rectified and delays where mineralised. Due to the site being located in the proximity of a residual property the site management had to include provision to deal with potential exposure to the public. Fortunately, ACE’s history of safe working meant that the extra health and safety considerations where all part of the job. The number of eels that are already using the pass gives a clear indication that the work of the Environment Agency and ACE has clearly paid off. ACE would like to thank representatives from the Environment Agency who were invaluable to the success of this project.