Published: 11/02/2014 14:38 - Updated: 11/02/2014 14:45

Fish burn project completed in Moray

SALMON stocks in a Moray river will be able to move more freely after the completion of a fish burn project.

The new fish pass at Davidston Burn, near Keith.
The new fish pass at Davidston Burn, near Keith.

Scottish Water funded a scheme to construct a pass on the Davidson Burn, which feeds the River Isla south of Keith.

Modifications to a weir on the burn which functions as a raw water intake mean fish can now reach good habitat upstream.

The weir also provides drinking water for Keith and surrounding areas, although the benefit spans Moray and Aberdeenshire.

Scottish Water project manager, Don MacLean, said a study carried out by his firm showed the weir impeded fish passage, but at least 10km of relatively pristine suitable habitat for salmon lay upstream.

"Although not a complete barrier the Davidston weir significantly restricts salmon and sea trout access to areas upstream of the weir," said Mr MacLean. "The Davidston Burn is seen as the most important stretch of river in the Upper Isla catchment."

He said the changes to the burn and weir were relatively simple. A pre-barrage fish pass now raises the water level downstream of the weir through the formation of a series of pools which act as ‘steps’ allowing fish to reach the good habitat upstream.

"It was proposed to construct the pre-barrages in blockstone and to ensure the downstream pools have varying dimensions and depths to soften the structure and present a more "natural" appearance while retaining structural integrity.

"This will raise the water levels immediately downstream of the weir and by dividing the drop in water levels will enable the passage of migratory salmonoids.

"It also benefits the otters, as the fish pass incidentally makes in-stream passage for otters easier. The fish pass also allows salmonoids to travel upstream unimpeded, which will increase otter prey availability upstream, and will therefore potentially allow an expansion of the normal range of local otters, and potentially allow an increase in the viable number of otters locally.

He added that work was carried out by Scottish Water’s delivery partner Morrison Construction who were appointed after a tendering procedure.

"We worked with SEPA and the River Deveron District Salmon Fishery Board to ensure the pass was fit for purpose. Our budget was £187k for the work but we expect the final cost to be significantly lower once we formally close off the project.

"One matter that arose during the pre-construction survey work was the discovery of an Otter Holt nearby. The necessary licence was obtained and the precautions observed to ensure minimal disturbance to the wildlife.

"The fish pass is now operational and working as designed. In the years to come it will play a small part in enriching the natural environment in the Isla catchment."

Richie Miller, senior biologist from the Deveron, Bogie and Isla Rivers Charitable Trust said: "We are absolutely delighted to have the new fish pass completed which will complement other fish passage works already completed downstream last year."

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