Our fish pass and screen cleaners

This photograph shows the high velocity flow of the fish pass entrance, controlled by the associated sluice gate. The white base holds the fish counter resistivity strips and with counting validated by use of cameras in the glass fronted housings on either side.

The second photograph shows the turbulence created by baffles in our European best practice Larrinier fish pass – and the velocity of water leaving the pass, attracting fish from mid stream

Screen cleaners, operating as wiper blades on the hydro inlet rake debris into the launder channel that has water flowing down it, through a mesh, and back to the river.

The screens are of a large area (15m x 3.3m) so that the water velocity is below 0.25m/s and thus fish can easily swim away and down the fish pass, which has a much higher velocity.

We have been amazed at how much plastic of all types is taken out of the river by these cleaners – in addition to several tennis balls, two footballs and a rugby ball!