Pilot: flexible baffles for fish on the Dysynni

We’ve installed flexi-baffles inside a 10 m culvert in the upper Dysynni catchment, downstream of key spawning reaches. This pilot is testing a simple way to help fish through short, man-made obstacles.

The baffles create small resting pockets, reduce local water velocities and encourage thin patches of gravel to form on the culvert invert, making conditions more natural for fish and lowering the energy needed to swim through.

Because they flex under high flows, debris and spate water can pass more easily than with rigid timber designs, then the baffles return to shape as levels drop. This is a fish-passage habitat trial, and we’ll monitor performance over the coming

This work has been carried out thanks to sustainable fisheries funding from Natural Resource Wales.