Design and environmental services to satisfy Environmental Agency requirements and upgrade the brook’s ecological potential

Lukely Brook National Environment Programme: Fish passage enhancements

The Lukely Brook is designated as a Heavily Modified Water Body under the United Kingdom’s Water Framework Directive due to historical use supporting industry and providing potable supply. As a result, the brook flows through a series of mill ponds, leats, and fords, and has poor ecological potential.

Stantec was engaged by Southern Water Services to design fish passage enhancement structures to help upgrade the brook to good ecological potential and satisfy Environment Agency requirements. Outcomes included replacing the Carisbrooke Mill and Waterworks Pond sluices with Larinier fish passes and eel ladders, constructing four pre-barrage weirs to overcome the Wellington Road Culvert, and replacing what was known as the Garden Weir on private land with three sequential rock weirs. We used detailed hydraulic modelling to test the efficacy of the fish pass structures and mitigate impacts on flood risk.

The Lukely Brook scheme received regulatory approval from the Environment Agency. Upon reviewing our scheme, they stated: “We know that barriers to fish movement and fragmentation of fish populations can be very damaging. The project delivers a significant outcome for the environment.”