Update on the Landslide that Blocked a Major River in Canada; Expected Flood Heights

In Canada, it has not been 5 days since a landslide just blocked the major Chilcotin River. In the days since the initial slide, additional portions of the same hillside have also collapsed while at the same time the ever growing lake expanded to more than 9 kilometers in length. Due to the risk of this dam potentially bursting and causing hundreds of kilometers downstream, numerous alerts were put in place all the way to Vancouver. This video serves as an update with new information, as we now know the expected worst case scenario flood heights for when this disaster occurs.

Thumbnail Photo Credit: Dr. Richard Roscoe, Photovolcanica, Licensed Image

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Google Earth imagery used in this video: ©Google & Data Providers

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0:00 Chilcotin Landslide
1:38 Predicted Flood Heights
3:10 River Warnings
4:10 New Evacuations & Alerts

[bobwhite]

The river has now overtopped the landslide/dam. It's flowing quite slowly so far.

[bungalo]

I wish every educator and youtuber was as thorough and concise as you are

[danielirvin]

The BirdNerd channel has video of water flowing through the downstream side of the damn as of an hour ago.

[vesmcbc]

You provide better, and more interesting, information than our local media. You rock! Thanks!

[llCoupDEtatll]

Woah, it feels crazy to actually see you talking about an event that is actually happening directly in my neck of the woods

[aegrotattoo]

Thanks for the great coverage. Its different watching an area that is my familiar backyard, definitely impinges seeing all the places dear to my heart. Then at the end to see the Hope Slide and memories of driving through that eerie land a couple of days after the first 'road' was punched through for local traffic. This province is nothing if not spectacular and demanding of respect.

[KbIMbIFbIMPA]

This reminds me of a landslide and mudflow that happened in 2007 at Kamchatka's Geyser Valley

[matthewjohnson]

Your humility and honesty are always welcome 😊

[wimwim]

Much of the coming scenario depends on the make-up of the slide material. If it is all sand and mud and other fine material, the breakthrough can be very fast and possibly catastrophic. If the slide contains a large amount of coarse rock (as did all of the the Hope Slide that you draw on for a false comparison for exactly that reason) it will considerably slow down and ameliorate the speed end energy of the new channel erosion through the slide. Maybe a better comparison is the 2010 Capricorn/Meager Creek/Lillooet River slide north of Pemberton that contained a mixture of (glacial) sediment and rock material. In any case, the consequences for the upcoming sockeye salmon migration will be devastating.

[TheSpaceEnthusiast-vlwx]

Thanks as always, Geology Hub! I hope everyone there is evacuating and/or prepared.

[tthappyrock]

One of the First Nations did a fly over not just of the slide but also of the areas impacted. The slide looks so much bigger than I envisioned! It's good to hear that the downstream impact of a breach is less than you expected. Others in the comments are saying that the dam was over topped a bit ago. That's also good -- thinking about not just a prolonged back up but also looking forward to fall/winter rains which could add significantly to the impacted areas.

[thegoonshow]

Thank you for the coverage of this. All of the other "geologists" I follow here on Youtube have said nothing about this.

I guess if it isn't rocks or volcanos they don't seem to care.

[kento]

I'd like to hear about the earthquake in lake Michigan. Lots of lips flapping about it but no info about what caused it.

[PlayNowWorkLater]

Appreciate the update. We’re all watching whatever footage we can get up here

[dorothydecesare]

Thanks again for update … clear, concise, and in language the average person can understand. Glad that you referenced the Hope slide …
Also glad you pointed out that this could take an extended period of time to resolve, and that currently still activity in slide area. Imo will be hard to keep people out of dry river bed downstream. So enticing to a certain segment of population. 😮

[JackMellor]

Update:
The water has found a way through, not overtopping but from the one chopper footage I’ve seen it appears to be internal piping and erosion that’s burst through midway up the downstream slope. This means that the entire mass of rock and earth is filling with water like a sponge, literally the temporary dam is getting soggier and soggier and thence more unstable, which could lead to a more catastrophic failure where the dam just slumps forward and the water flows out.

[xwiick]

Thanks for all the hard work on these videos!

[AndreaCrisp]

Thank you for an update and sharing your expertise. Much appreciated!

[machscga]

Now how much water would make it to Vancouver if Mt Garibaldi did a VEI 6?

[xavian]

Thank you for the update! Its hard to find them