Within the past few years a forest fire cooked the side of a mountain in B.C.'s interior. The soil stability was gone so a massive landslide blocked the Chilcotin river a few hundred miles from Vancouver. The slide contains dirt, rocks, lots of wood including long roots. The end result is a gigantic plug 3000 feet long, 300 feet wide, and 90 feet deep . . Will it come apart or carry on downward as a giant wad. It seems that nobody is sure what will happen. It eventually meets the Fraser river which meets the ocean at Vancouver. I don't live near the Fraser but a few hundred thousand others are a bit worried now.
https://www.youtube.com/watch?v=_wTRdjIlPIU
Mountain snows are still melting,, pushing into that mess,, hope nothing serious happens.
How about controlled explosive blasts to get it moving under some managed course. Not sure how one would predict results. Heck, call Al, let him blow the plug charge spectators to view.
But seriously, I would think a catastrophic release of the plug would not be a good thing. Brad
UPDATE: Within the last 2 hours the river has carved a route over top of the pile. It appears to be flowing well but the next question is how far will the debris travel and what damage it will do. Being on the shore of either river isn't a good idea for the next while.
Edited by - donc on 08/05/2024 15:59:39
Brad.. The explosives idea has been kicked around. If that idea turned out to cost lives or heavy property damage the province would be a sitting duck for a huge lawsuit. Its kind of like the fighting of forest fires. Back burning has been highly successful but on occasion the calculation is wrong or the wind changes direction. I'm glad I don't have to make those decisions.
IF I was in charge of controlling drainage with an explosion it might cost lives or unplanned/unforeseen property damage .... with somebody who knows what he's/she's doing the risk should be minimal. ....Unless the idea is to start BIG and then reduce subsequent attempts 'til we get it right. 
Edited by - Owen on 08/05/2024 16:05:15
One ..Big ..beaver dam...
quote:
Originally posted by rinembHow about controlled explosive blasts to get it moving under some managed course. Not sure how one would predict results. Heck, call Al, let him blow the plug charge spectators to view.
But seriously, I would think a catastrophic release of the plug would not be a good thing. Brad
Sounds like a job for our favorite make it a go booma guy. Will mister dinomite please pick up the phone.
Don, is the "plug" in the OP 3000' along the previous course of the river, or across the river/valley?
[I'm workin' on my plan for blasting, and I figure that point might come in handy. 
]
Owen,,, Have a look at the link in my second post. I think the landslide came down and did most of its dump into the river without filling up the other side. There are other vids on Youtube.
The Toutle River in the 1980 Mt St. Helens eruption is the analog. The Google monopoly won’t let me send the link, but you can search it out.
The fish will either find their spawning grounds, or spawn somewhere else as they have no other choices.
Several years ago we were meandering in Wyoming. We came across a lake formed by a landslide.... most likely Lower Slide Lake https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5340454.pdf
During field camp we travelled to and studied both the Madison River landslide in WI and the Gros Ventre River slide in WY. Regardless of the causes of the slides, both are similar as they damned up the stream valley below, subsequently causing a slide lake to form and then deluge of flooding. The amount of material deposited by these slides is unfathomable until you see photographs, and even then hard to truly grasp without being there and standing on it.
What will happen with the Chilcotin river is predictable, and yeah, not good for those downstream. I'm sure Canada's version of the Army Corp of Engineer's has a handle on it, have a good plan, and are washing their soiled underpants as we speak.
Edited by - Buddur on 08/06/2024 09:18:50
