Stair Dam receives some work to help fish passage

The dam before work started today. Flows were already reducing after the lade had been opened.

Ayrshire Rivers Trust staff fitted two timber baulks to Stair Dam today in order to help salmon over during periods of low flow. Last year there was such a shortage of water that the fish built up in the stretch downstream while upper beats complained of no fish. With the hydro fully operational since last year, it was now more important than ever that that steps were taken to help fish over. SEPA and the Hydro operators were supportive so with the river low at the moment, ART staff jumped at the opportunity to get this work done before we have any rain.

Salmon can of course make it over this dam in higher flows without too much effort but these additions are designed to work at the lower end of the scale without impacting anything during higher flows. They concentrate flows towards deep water and should be attractive to salmon waiting to run.

Starting to fit the first baulk
Final touches to the baulks before flow was restored. Two baulks have been fitted to the face of the weir

To help with the work, the gate to the lade was opened fully, diverting some of the flow off the dam. ART manhandled the timber into position and set about laying out to achieve the best results possible on a rough weir face. The timber baulks were 200mm x 200m untreated Larch and they were drilled and anchored onto the face of the weir using a dedicated underwater resin to secure galvanised studs to the face of the dam. Once set, the nuts were tightened down and the excess threaded studs cut off.

The lade shut down and the levels back to normal. You can see that there’s increased depth beside the timbers.

These timbers are set at an angle across the face of the dam and will concentrate the flows behind the baulks. This will ensure that there’s adequate depth for salmon to make it over the weir even when we are facing prolonged dry spells. That’s the aim anyway and ART will monitor to see how they perform.

The angle of the timber is more obvious when viewed from downstream

ART were grateful to Ricky Shearer who keeps an eye on things for the hydro operators and assisted today.

 


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