I took a walk over Beinn an Lochan in Arrochar on Sunday, with rain turning to snow and icy conditions for summer boots near the steep top of the north-east ridge. I came down the other side, above the summit of the A83 Rest and Be Thankful and the Lochgoilhead Road, traversing round grassy hummocky slopes.
On my way I came across the remains of a landslide, lots of mud and rocks, and the vegetation battered down. This wasn’t a huge event, I suspect, by local standards, but it still looked pretty grim close up.
Looking across the valley I could see the roadworks on the A83, close to where the last landslide down the side of Beinn Luibhean closed it in October.
The sheer scale of the landslide scar, and the tiny size of the works, puts it into perspective, I think. Having seen my small local landslide up close, I can imagine a slide coming down this vast slope, with rubble, mud and boulders crashing down, all lubricated by heavy rain. While the mesh barriers at the bottom designed to stop landslides reaching the road are probably massively strong by engineering standards, they look pretty insignificant – well, almost invisible – on this expanse of mountain.
(Looking at the photo the slope looks steeper than maybe it is. The OS map seems to say it’s about 400m up in about 500m distance. Anyhow it’s bloody steep.)
Anyway the point is that from the point of view of this reasonably informed layman, putting mesh barriers up looks like a pretty poor way to stop the landslides hitting the road. They do seem to be excavating some big holes next to the road now, which would catch a lot of the crap, but I can’t help thinking that the time, cash and effort spent on all this would be better spent on a concrete canopy.
The best chance of dealing with these huge forces is to deflect them , over the top, rather than to stop them dead. I don’t want to get started on the cost of the pointless new Forth Bridge versus west of Scotland infrastructure, but a few million quid of that cash could have probably done the job….
It also struck me how the top end of the road down to Lochgoilhead from the Rest, which has similarly angled slopes above it, with similar geology, doesn’t as far as I know get closed by landslides, even though as I saw for myself, they do happen here. The difference I would guess is all the conifers growing on both sides of the valley, anchoring the soil and blocking the biggest surges.
I’d like to know if the Forestry Commission Scotland report from 2012 suggesting planting native trees such as alder, blackthorn and oak on the Beinn Luibhean slopes has received any attention at all ? The landslides have been happening for years, and it would have been sensible to start planting years ago, but as far as I know nothing happened, and we still see sheep, cattle and deer on parts of that hillside, cropping the vegetation to within an inch of its life.
The impact of road closures in this region, where they are the only effective route to vast areas, has a disproportionate effect on the population, as those areas depend so heavily on tourism. Tourism businesses will probably dread these A83 closures, just like they hate the A82 along Loch Lomond being closed by accidents.
It’s time to think, come up with a proper solution, and let those people that depend on the A83 rest easy…