Wednesday 19th February 2020, 3:58pm
Nearly a year on from being awarded planning approval there are signs of work in the glen – a new overhead powerline being constructed and new passing places being constructed along the road, as well as some progress on a couple of the schemes that lie in the forestry on the west side of the glen.
But what about the three controversial proposals for the east side, the wilder side of the glen? Silence so far on Allt Mhueran, the one on the route up to Ben Starav, and on Allt Ceitlein. And for Allt Chaorainn? No work has started here, and the developer is slow in coming forward with proposals.
On The Highland Council’s planning portal we can see plans for a bridge over the River Etive for construction traffic, the power house, an access management plan, and designs for the two intake weirs further up the burn. Tellingly there is still no plan for how the penstock, or water pipeline to power the turbine, will be constructed on the thin soils and bare rock of the Allt Chaorainn without ripping the heart out of the landscape.
The plans for the intake weirs show the scale of the operations – this is no simple diversion of water to make electricity but a major civil engineering project in a landscape with our highest protections. This is conveniently illustrated in the drawings with the figure of a man in a hard hat for scale, standing by the works.
What is of concern is that there is nothing in the plans to indicate that this structure is capable of coping with the severe weather events that have been becoming more frequent. Rainfall has been prolonged and heavy and these high-energy spate rivers are powerful. Other run-of-river hydro projects have suffered with these flash floods and in some cases the intake has been choked with boulders and debris and the burn channel has changed direction.
Where is the guarantee from the developer that these weirs on the Allt Chaorainn are able to cope with what the weather throws at it? Has the developer looked at extreme weather and the ability of his designs to withstand it?
It would be interesting to hear what civil engineers think about this. The Highland Council need to robustly assess the implications of extreme weather on the plans to avoid an embarrassing disaster. Or better still, the developer realise that this is really not the place for heavy engineering and focus instead his attention on the four schemes in the forestry plantations.