Fish Passage Creation
Fish passages provide a means for fish species to fully utilise available habitat and complete their life cycles. We’re proud to provide full fish passage creation service, including design, installation and monitoring.
Where possible, we will aim to remove existing barriers completely. However, there are options available when this is not possible, such as naturalised fish bypass channels; technical fish passes (e.g. Larinier); and non-technical fish passes, such as rock ramps, pre-barrages and low-cost recycled baffles.
We work in line with the Environment Agency’s Fish Pass Manual to ensure that the most appropriate and cost-effective fish passage solutions are used at each point, providing passage for multiple fish species where possible.
FiveRivers can act as both a designer and contractor for your fish passage creation project. We are also perfectly positioned to liaise with regulatory bodies in order to obtain fish passage approval and environmental water transfer permits.
Barriers in Rivers
Some fish species are born in freshwater (rivers and lakes), spend most of their lives out at sea, before returning to freshwater to spawn (Anadromous/Diadromous), while others have the opposite lifecycle (Catadromous). Barriers in rivers and waterways can drastically impact these two species, preventing access to habitat that allows them to complete vital life stages.
While certain species, such as salmonids, are able to jump smaller barrier, coarse fish species, Eels and smaller salmonids are not be able to travel in the same way and may be restricted in their ability to reach their spawning habitat.
Fish passage is key to improving Water Framework Directive status. Under specific legislation, such as the Eels (England and Wales) Regulations 2009, there is also a requirement to improve passage for this single species.
There are many different techniques to improve fish passage, depending on the specific site conditions, constraints and species of fish present; each project will be different.
Our preference is full removal of the barrier, but this is not always possible or desirable. We have a toolkit of available options that we can use to deliver fish passage based on the specific site constraints and conditions. Where removal is not an option we favour a ‘nature-like’ fish pass solution, bypassing a structure with a naturalised channel or creation of a ramp (e.g. low cost baffles or a rock ramp) to allow fish to traverse an obstacle. When we so need a more engineered solution we will develop a pool or baffle-type design built on the structure within the constrained channel.
We have acted as principle contractor, delivering fish passage projects, on a variety of schemes from small easements (£20K) to large scale naturalised passes with complex offtake structures (£1Mil).