A project to improve water flow and fish migration on the River Carron has resulted in the removal of a concrete weir.

SSE Renewables, the UK’s leading renewable energy developer and operator, the Scottish Environment Protection Agency (SEPA), and the Kyle District Salmon Fishery Board, who represent the angling interests on the River Carron, have worked together to agree the removal of the weir.

SSE Renewables has installed new flow gauging system in its place that does not require anything to be built in the river channel. This will ease the passing of fish upstream and minimise any visual impact whilst still collecting this much needed river flow data.

Built in the 1950’s as part of the Conon Hydro scheme by SSE Renewables predecessor, The North of Scotland Hydro Electric Board (NoSHEB), Deanich weir was constructed as a gauging station to measure the river flows on the River Carron. The weir was needed to allow the hydro-electric board to meet its commitment to environmental management by demonstrating the agreed flows were being maintained in the river.

Due to its design, the weir posed a partial barrier to migrating fish who travel upstream to their traditional spawning grounds. The new flow monitoring equipment, now situated above the water level, will allow fish to move upstream without restriction.

For fish such as Atlantic salmon, sea trout and lampreys, free passage between the ocean and freshwater environments is an essential part of their lifecycle for breeding and spawning. Removing obstacles which may have partially blocked these migration routes helps the recovery of damaged fish stocks, while also preserving the natural ecology of Scotland’s watercourses.

Following the weirs removal, the concrete from the weir was repurposed to fix some of the roads on the Alladale estate, helping to reduce waste and any environmental impact of the removal.

Iain McMyn, SSE Renewables Environment Advisor, said: “For over three-quarters of a century our hydro assets and schemes have provided renewable power and water management to the north of Scotland.

“When these schemes were first built, we agreed a duty of care to ensure we minimised the impact on the natural environment and that is still our ethos today. We’re very pleased to have worked with SEPA, the Kyle DSFB and Alladale Estate to remove the weir and replace it with a less impactful flow gauging system and look forward to working together in future on more innovative projects to benefit the environment we work in.”

Richard Fyfe, Water Specialist from SEPA said: “The removal of these historic partial barriers to fish migration brings huge benefits to our natural water environment and help to unlock traditional spawning grounds on the River Carron for Salmon and Trout. It’s encouraging to see SSE Renewables tackle the legacy issues which these barriers can pose for the health of Scotland’s rivers and look forward to seeing the ecological benefits this will bring over the coming years.”

Keith Williams, Director of Kyle Fisheries, said: “Research increasingly shows that manmade structures can prevent or significantly delay fish migration and obstacles and barriers thus represent a key pressure at a time when salmon stocks in particular are very fragile.

“As such, Kyle Fisheries is delighted to have been able to work with SSE Renewables and SEPA in the removal of this redundant structure.”

Innes MacNeill, Reserve Manager at Alladale Estate, said: “We at Alladale Wilderness Reserve were pleased to see the removal of the weir below Deanich Bridge in August this year. It’s great to see another man-made obstacle being removed from the river. Our thanks go to SSE Renewables for making this happen and to the contractors that carried out a high standard of work. We’re also pleased that the material did not go to waste and helped fill some potholes on the access track.”

The work at Deanich is linked to another project which involves the alteration of a weir further upstream at the Glenbeg intake. This work is due to be completed in summer 2020. SSE Renewables and SEPA are working in partnership to alter mitigation flows at the Glenbeg weir to ensure the same amount of water will be flowing throughout the year which will bring enhanced ecological benefits to the river.