I returned to Catrine first thing this morning to see the shutters come off yesterday’s concrete pours. Everything seems fine and the joiners quickly set about fitting the formwork for the crest of the weir that they hope to pour tomorrow.

The final shape of the newly formed, below water, take off area. Overall depth is about 2m deep at the weir face so salmon should be able to come from directly below the fall.

The final shape of the newly formed, below water, take off area. Overall depth is about 2m deep at the weir face so salmon should be able to come from directly below the fall.

Joiners fitting the formwork for the weir crest and wall. Weather permitting, the concrete will be poured tomorrow and flow restored completely on Monday when we should see the results of all this work.

Joiners fitting the formwork for the weir crest and wall. Weather permitting, the concrete will be poured tomorrow and flow restored completely on Monday when we should see the results of all this work.

Over the weekend, water will flow through the bypass pipe allowing the concrete to harden and strengthen. before being restored on Monday. The top end of the bypass pipe will be sealed with a 1 tonne plus, concrete plug that will be removable if work is ever required in future.

A 1T+ concrete plug will seal this pipe on Monday and be buried below rocks. It is there if ever needed in years to come.

A 1T+ concrete plug will seal this pipe on Monday and be buried below rocks. It is there if ever needed in years to come.

Finally I’ve added a photo of the new boulder field that has been installed at the upper weir. This serves three purposes. Firstly it helps stabilise the upper weir structure. Secondly it should deter most fish from attempting to swim over the smooth surface of the dam and finally it will also help guide fish to the fish pass. It is constructed of rock armour concreted together to form a large stable mass. I notice the smaller boulder near the right bank haven’t been concerted and unless they are, they will disappear rapidly with every spate. I will check if this is included in the plans.

The boulder died designed to guide fish to the bottom of the ladder and deter them from going over the weir.

The boulder field designed to guide fish to the bottom of the ladder and deter them from going over the weir.

Progress has been made and once the weir crest is complete and the plug is in the pipe, I can’t wait to see how it all looks and performs during the next spate. Almost all the work so far has been to improve fish migration and everything looks as thought it should work well with just one exception… the eel pass. I just can’t believe this will work at its current levels. The intake is between 750mm and 1000mm above the water level and unless there is a pump planned to lift water to the pass (and there isn’t), I fully expect this will have to be redone. I did express concerns at the time it was installed (for which I was called an idiot!) so I’ll just wait and see. This idiot knows water doesn’t flow uphill.

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6 Responses to Photos from Catrine this morning

  1. Scott says:

    As always, good pictures and insight into the progress which is great thanks.

    Quick question on the boulder front, why would you want to deter salmon from going over the weir? Wouldn’t it be better to allow them multiple routes to pass through, especially as some block the ladder occasionally. Making the weir easier to get over would have been a better solution IMO as it’s not likely many poachers will run that weir with the pass in the way. However I do realise there may have been blockers to alter the weir in any way given it’s protected status, if that is the case.

    Interested to hear your thoughts on that one?

    • Stuart Brabbs says:

      Scott, there are several points to make in answer to your question. I’ll try and provide a logical run through but I don’t have the approved abstraction figures at home so I’m not going to be too specific as to when abstraction will take place. You are correct that there was restrictions on what could be done to the weir and this largely dictated that either the current fish pass should be used or replaced but the location wasn’t
      The height of the weir will be raised by around 300mm at the bottom edge by the time it is encased in lime mortar. The crest will remain the same height but will have a metal edge. The entire surface of the weir will be finished in a smooth lime mortar. The tank that once offered a place of rest/refuge and sometimes became a trap (a poaching target) has been infilled and lost. As CCT plan to abstract considerable volumes during high flow events (at certain times of the year), up to 4cubic metres per second will be drawn off through the voes rather than over the weir crest. The flow down the fish pass will be controlled by ensuring the designed capacity of 0.5 cumecs is maintained. Excess water will be returned to the lower fish pass chamber. The volume going over the crest of the weir may not always be sufficient to allow successful fish passage by this route even during natural spate events. Rather than leaving salmon exposed and struggling to swim on the dam back and possibly easy targets for those inclined to remove them, preventing them taking this route seemed the best option. Of course in very large spates fish may take that route but most fish tend to run obstacles on a falling water.
      By improving the obstacles: the fish pass, Andersons and the entrance to the fish pass, the hope is that fish will move quickly through the whole weir complex, without expending too much energy in the process. Fish should easily get over Andersons and then find the entrance to the pass easily. With the pass operating at its designed flow (the fist time since it was opened) salmon will hopeful be able to quickly pass through. By speeding up this process, it is hoped that fish won’t lie exhausted in the Boy’s Hole for as long and should redistribute themselves upstream. Perhaps as the season progresses, damage to developing eggs in hen fish may be reduced and this may bring about improved spawning success.
      By making the fish pass more attractive and easier to get through, the need for the tricky alternative is reduced. I have watched poachers attempt to take fish off the dam back before and the fish pass was no deterrent. In future far fewer salmon will go that route. With the pass becoming the only real route through, the DSFB and ART consistently highlighted the need for heavy duty screens to prevent access, tampering and poaching. CCT have refused to provide this. Time will tell whether this is a mistake or not. I fear it is a grave error of judgement. For safety’s sake alone, I would have thought it wise to cover the fish pass. Despite the reduction in entrained air, there is still too much in the pass and anyone falling in there will sink like a stone.
      Of course the best option would have been a new fish pass but apart from the fisheries interests, no one was willing to consider this. Fish were not the top priority in my opinion.

  2. Scott says:

    Thanks for info Stuart. There is logic in the way it’s designed and from a spawning point of view, hopefully it will result in improvements.

    From a selfish perspective we won’t see as many fish either leaping at Anderson’s due to the new design, or running the Weir by the sound of it and so may be more difficult to judge how many fish are running the river as this was the best place to see them. Hopefully this will be offset by improved catches up past!

    • Stuart Brabbs says:

      That may be true but may also reduce the unwanted interest in the fish. Remember there will be a camera and counter added to the fish pass before it is completed. This will allow us to assess the movements through the pass if CCT allow us access to the raw data (I’m sure they will). Unfortunately it won’t tell us how many fish progress into the pass and then fail to go through but that’s life. I hope this camera will be in place before the end of this years migration.

  3. ian radburn says:

    hi stuart looking good so far but i still have major concerns about the fish pass all the salmon will be routed through the fish pass i think the poachers will block the pass any chance they get but otherwise a great improvement

    • Stuart Brabbs says:

      Ian, I fully agree with your concerns. The Board and ART have pushed for screens over the pass repeatedly but CCT refused to do this. Apparently according to their local angling club contacts, poaching is no longer an issue at Catrine!!!!This is the advice they took over the Board, Bailiffs and ourselves. I’d suggest raising this at the AGM if you feel inclined.