Arobwk, this is something I’m interested in. We have some lovely burns and one in particular. I’d like to create naturalised, partial damns along it, with a central channel to hold back more water at all times and slow the flow when it’s in spate. However we’d have to jump through many hoops and would be worried about getting something wrong or even inviting the people in to ask what we could do in case they’d find fault with something.
Doing this might make sense to me but everything is more complicated than it seems.
For one thing, creating dams and blockages slow water and can create habitat and reduce soil erosion. However these things can also increase erosion as anyone who’s seen a watercourse changing its path due to an obstruction will know.
Leaky dams which are sometimes popular for slowing force of water don’t always provide good access for fish (too big to access the gaps in silted up branches unless there is a good flow over the top). I’m also interested in the long term effects of these; do they eventually silt up completely?
The beaver dams that I’ve seen near Kirriemuir have largely been removed periodically requiring diggers to be brought into the sites and now large metal cages built around culverts under bridges. Otherwise the nature reserves paths and probably hides would be underwater. The beavers have felled a fair amount of trees and the reserve’s staff have put chicken wire around remaining trees so that they aren’t damaged.
They seem to be less of an issue on larger waterways like the Tay.
I feel we live in such a managed landscape that I don’t look forward to the day when I have to start wrapping trees in chicken wire, hiring diggers in to keep our access bridges open, having metal cages built to stop them damming under bridges. I’ll be very please to watch them with the children.
And it still feels hypocritical that beavers can ringbark and kill the riparian trees (which taxpayers paid to have planted because they are ‘needed to stabilise the banks and create beneficial waterside habitat’) and build their dams and obstruct waterways for fish, but I would have to get licences to do either of these things and spend time and money replanting the trees! (Lol! Rant, But it’s been a long day!)