I assume this exposes hidden methane hydrates to thaw even quicker, accelerate microbial activity, allow subterranean gases to emerge and may well divert established waterflow toward raw earth. A couple of times in my life I’ve been close to landslip material and its a substance unrealised until one has seen and handled it.
An aside, my own husbandry of a watercourse to help reduce erosion … a place I know has had needlessly a mile of ditches re-dug which were very old and functioned fine already, the field border and ditches date from 1680 are moss lined, bound with perennial herbs and a highly efficient web of roots both fibrous and woody to bind it all together. Lots of runs, holes and trackways from I guess vole activity. Now all this has been scraped away and dumped onto the other side of the road, exposed raw earth will most certainly be eroded and washed down as is already evident a few weeks following the needless so-called ‘improvement’ … the complete mile is on a hill and runs down in basically a straight line downwards. This is new work is a recipe for disaster. Again, I know that hill and for the last few winters merely as an anonymous citizen have known which drainage conduit to unblock with my six foot pry-bar to get things functioning (mostly from fly-tipped builders and garden waste) yet also each year for days previous to my visit all the locals, farmers, gamekeepers, middle class out of town country dwellers have sailed past in their cars and done nothing as the torrent carves out and undercuts the edge of the road. So, as yet again the man in the digger has no intimate knowledge of what he is doing, no perceptible aptitude and merely wrecks what already functions perfectly well. A case in point being run off channels where I don’t think run-off will occur in many cases. I guarantee as is already being demonstrated that once the heavy rain run-off flushes downwards the silt build up will in fact create flooding, blockage, overspill further down where none need have occurred. I often think man as a labouring animal, as trying to engage with intelligent / common sense husbandry is increasingly becoming useless at this small intimate scale. Further down, each year I also quite easily can divert side of road run-off back into the drainage channel merely banking a few inches of earth and voila! … job done. The digger driver has completely ignored these points / locations. My charming aside re basic hydrology now finished, back to the dreaded thawing permafrost.