Massive Rockslide Blocks the Might Fraser River

[seewood]

Looking at the material in the various pics available in the surrounding cliffs, I wonder the size of the material in the slide might be small enough the flow of the river will, over time, scour the blockage. Question, how long?

In the catastrophe in 1914, the material was blast rock and large pieces of rock could not be moved by the river, hence the fish ladders 30 years later.

Regardless, timing could not be worse as most of the Fraser salmon spawning is above the slide area and the peak of the run in this area is August.

[Omnitheo]

In 1914 a blast from the construction of the rail way slid into the Fraser at Hells Gate, blocking the salmon from moving up river. That decimated the coastal fish stocks, especially the Chinook.

In 1946, I believe a fish ladder was constructed on the west side of the canyon and salmon once again could move up river.

I suspect this might be what biologists are thinking about today. When the water drops I'm sure the professionals will get a better handle on what they are dealing with.
For the time being, early run Chinook likely could be backing up at the slide location, not a good thing. The upper and middle Fraser runs could be knackered for a bit but just perhaps low water flows later this year might let the salmon pass this.

in between the slide, and the construction of the ladder, First Nations tribes would catch fish and carry them up stream to where they could continue their journey. Be it a natural occurrence, or human made doesn’t change the impact it has on the ecology, or the people and economies which depend on it.

Hurricanes. Droughts, tornados, floods, etc have been natural. But when mill creek flooded, we didn’t just ignore it because "streams flood, nature will take care of itself"

[LTD]

ya youre right lets get in there and dig it up just like we did in mission creek, because we're so smart and think we know more than mother nature the kokanee numbers are still in the toilet, and because we don't learn we go back and dig it up three or four times just to make sure the numbers stay low

[Mark5]

This happened once before, years ago. I cannot recall the details.

[waynetyea]

they better blow it now or as they say just wait 30 years for it to fix itself... ya sure... they took 30 years to fix the hells gate and they lost 70 percent of the returning salmon for another 100 years... drop a big bomb in there and make it passable for the fish to spawn or else loose it all. this is a no brainer... just giter done or else.

[bob vernon]

A really big bomb. Blow it up good. Blow it up real good. And maybe bring down the walls on both sides and cause it to back up good. Real good. And then suddenly it might let go all at once and wipe out the roads and rails downstream. Maybe even wipe out Hope. Git 'er done!

[Urban Cowboy]

Given all the blasting done to control avalanches, build roads, etc., I'm sure there are a few souls around who have the smarts to calculate how much of a boom to make. Nice try though.

[Anonymous123]

Now the salmon may get caught, loaded into a truck and moved past the landslide. Would this not stress the spawning salmon? I’m sure if they leave it alone nature will solve the “problem”. It’s not the first time watercourses have been altered in the history of this world.


https://www.castanet.net/edition/news-story-260367-3-.htm#260367

[rustled]

They'll die either way, so at least some of them will make it to the spawning grounds. If we do nothing, they won't.

IMO, this is a time when our intervention would actually be a good thing.

ETA: I stand corrected, some of them are making it through. If it's only a small percent of the run that's getting through, I'd still support moving them past the blockage.

A lot of these salmon are on their way to spawning channels where we have already made significant improvements to give them and their offspring their best chance of survival.

[Queen K]

https://www.castanet.net/edition/news-s ... htm#260770

More bad news. Just doesn't stop does it?

[Glacier]

https://www.castanet.net/edition/news-story-260770-3-.htm#260770

More bad news. Just doesn't stop does it?

That might be a good thing. It could flush out the rocks.

This rain has been crazy. My friends who live in the Chilcotin say it has rained 12 of the past 13 days. In just the past 4 days there's been 90mm alone in the Big Creek area! An interesting fact about the Chilcotin is that the main river sources (Taseko and Chilko) are fed from glaciers so they don't peak until July. Add in 4 inches of rain on the normally dry plateau at the same time, and you get a 1 in 200 year flood.

Here are some pictures from near Big Creek where the heaviest rain fell. https://www.cbc.ca/news/canada/british- ... -1.5205014

[rustled]

There's generally more erosion in the first couple of years after a forest fire, too. Is that compounding the problem?

[Glacier]

There's generally more erosion in the first couple of years after a forest fire, too. Is that compounding the problem?

Absolutely. The Hanceville-Riske Creek fire burned 240,000 hectares of forest in 2017. Add in all the pine harvest at the higher elevations to the south, and you have very little in the way of trees left.

Here are a couple of Google Earth shots showing this. Note that Big Creek is the creek that's causing all the flooding right now (and much of its watershed was burned in 2017.

[Hurtlander]

What I don’t understand why the so called authorities think the salmon won’t be able to swim through this.

[Hurtlander]

^^^ Yet salmon are able to swim through these rapids just upstream from my house...