After years of negotiations, work finally commenced this week at Catrine Dam. This is a two pronged project, 1. To install and operate a hydro scheme and 2. To stabilise and protect the weir.

Catrine Community Trust are in receipt of the appropriate CAR licences from SEPA to allow them to abstract water from the dam, through the voes system and turbine house before returning the water to the river approximately 800m downstream. Prior to commencement of this operation, they must first improve fish passage at the dam to allow the migratory species to pass more efficiently through what was a poorly functioning ladder. After much debate and at times terse exchanges between the DSFB, ART and Catrine Community Trust, a final plan has been approved by SEPA that allows the project to continue. Whilst it wasn’t a solution that the DSFB or ART thought ideal, it is progress and some key improvements have been included, particularly at Anderson’s where the gap will be widened, the water velocity reduced and the eroding concrete is to be stabilised. This should allow salmon and trout to reach the bottom of the fish pass with ease. The velocity and turbulence within the fish pass is also to be reduced to allow migtration through the pass to be improved. This is especially important as during the hydro abstraction periods, there isn’t likely to be a route of passage over the dam itself as currently exists except during very high water. During low flows there is a ‘hands off’ level at which point abstraction and hydro generation will cease. The fish pass improvements will be monitored and a camera/counter system is to be installed to assist with evaluating fish migration.

Anderson's where the gap will be widened to approximately the width indicated by the red line. The concrete which is collapsing will be stabilised and the pool below the fall will be deepened by removing bed rock allowing the fish to take off closer to the leap.

Anderson’s where the gap will be widened to approximately the width indicated by the red lines. The concrete which is collapsing will be stabilised and the pool below the fall will be deepened by removing bed rock allowing the fish to take off closer to the leap.

To ensure that the weir itself doesn’t collapse (it is a scheduled ancient monument and is therefore protected) the dam must be stabilised and encased in lime mortar. As a component of this work, the alterations to Anderson’s Leap will also be delivered. This work will take place over the coming months with completion expected in 2014.

Whilst the planned works didn’t all meet our expectations, it should mean that fish passage is improved and of course it will be monitored closely for efficiency. If the improvements fail to deliver the required results for fish passage, then further alterations will be required. Ultimately, we are seeking improvements over the current unsatisfactory situation and we expect this will be delivered.

Smolt trap

Smolt trap chambers

The work this week has included the installation of a smolt bywash chamber and pipe to take any smolts and kelts that are drawn into the hydro flow, back to the river. Included within this chamber will be a trapping facility by which the DSFB and ART will be able to monitor smolt numbers annually. Screens will be installed to prevent fish passing into the voes and through the turbines.

The smolt bywash pipe. It will enter the river below the surface and return any smolts and ketls to the river. I understand there is to be a large pre fabricted concrete section on the end of this pipe.

The smolt bywash pipe. It will enter the river below the surface and return any smolts and kelts to the river. I understand there is to be a large pre fabricated concrete section on the end of this pipe.

We also saw that the fish pass has had some work done to it. A hole has been cut into the side wall of the lower chamber to allow the water that is to be diverted from the upper chambers to be returned to the lower chamber.

The hole in the side wall of the fish pass can just be seen.

The hole in the side wall of the fish pass can just be seen.

One final point is that neither SEPA nor the DSFB hadn’t been notified in advance of this work taking place although it had been approved in principle. Final details of the smolt chamber and entrance have yet to be agreed or issued to the DSFB for consultation. Lets hope the lines of communications between the parties involved is improved to avoid any further issues arising.

 

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2 Responses to Work commences at Catrine Dam

  1. Darren says:

    Stuart I see this as nothing more than a empty gesture by the community trust so they can progress with there plans ,why not make all the relevant and required changes to save further disruption and by there lack of communication with qualified bodies such as yourselves only indicates a disregard for the issues with migratory fish an d also with the changes being made to the fish pass such as a counter being installed and a hole being drilled for flow has any plans been implimented to improve security of the fish pass

    • Stuart Brabbs says:

      Darren,unfortunately the regulations pertaining to existing fish passes are different to the regulations for new fish passes. As there is an existing fish pass we have little leverage to force improvements. Sad though that is, SEPA deemed the proposed modifications to be adequate BUT may require further improvements depending on how the fish pass performs after the alterations. One big failing I see is that there was no attempt made to quantify the efficiency of the pass in its current state so how improvements will be measured is vague. The camera will be a great benefit for this but still no base line data will be available. All we can do is compare smolt output over the next 2 years with what follows in 2016 onwards. We will also be able to compare the number of fry in the reaches below the dam to see if there is a reduction there, in which case it may signify that more fish are successfully negotiating the structures at the dam.
      You are correct, no improvements are confirmed for the fish pass security itself and Catrine Community Trust were evasive on whether they would fund this in future. They did however give assurances that they would consider screening but it seems increasingly unlikely at this stage as they had no budget for this currently. The view that there had been no prosecutions for poaching at the dam was taken as a sign that there isn’t really a significant problem there. This we all know to be incorrect however, this view prevailed despite vociferous arguments to the contrary. We all know that the pass can’t be watched 24 hours a day and are concerned that if more fish use the ladder, then more fish are at risk of being removed unseen.
      Whilst we didn’t get everything we asked for, I do believe that salmon, trout and eels should be able to pass through Andersons and the fish pass easier and quicker than before but time will tell.