Conifer tree soft engineering works Bealanbrack River

Habitat Enhancement

The enhancement of river habitats that have suffered from external pressures.

Habitat Enhancement

In the past, many Irish rivers have been severely impacted by human activity, mainly to facilitate land drainage. In some cases, the natural habitats on which a huge variety of our native fish and wildlife rely has been removed or damaged. Each year, Inland Fisheries Ireland staff survey a number of these channels and develop river habitat enhancement plans which aim to restore these rivers to something close to their natural state.

Featureless drained river channel

A drained channel with no bends, uniform gradient and no shade.

Once the initial survey is complete, a decision is made as to whether development is needed and likely to improve the habitat on the river. When a site is approved for a development plan, a series of structures are proposed which will be placed in-stream. The replacement of gravel, construction of deflectors and the scouring of pools are all methods used by Inland Fisheries Ireland in their project designs to improve damaged river habitats.

These structures are designed to mimic the natural processes which are found in flowing water. They introduce meanders and a variation in the flow and strength of the river. This in turn provides a mix of shallow, deep, fast and slow areas within the channel. Fish of different sizes and species can then find appropriate niches within the newly restored habitat and biodiversity can thrive.

The banks of the river (or riparian area) can also be restored where this is deemed necessary. Fencing to keep animals from trampling the banks and bed of the river can be very effective. This usually results in the establishment of natural vegetation along the bank, which is vitally important to creating additional habitat for many interdependent species that rely on the river habitat.

A fence to keep livestock out of a river

Fencing to keep livestock out of the river.

The ultimate aim of these habitat enhancement projects is to work with the natural riverine processes in order to provide improved river ecosystems for as many natural species as possible.