PNW Flood Watch - Dec 8-12, 2025

[Canuck from Kansas]

i'm with MattB and the other guys on this. We had plenty of warnings something potentially big was coming. Honest i think it might have gotten under estimated.

What surprised me is that news of our flooding has become world wide news. European and Asian news agencies have picked up the stories and run with them. A foot plus of rain in 72 hours is a lot of rain, no matter where or who you are.

Now add in the Alberta Clipper thats just started to hit the northeastern US. Some places there havent seen that much snow or temps that low in over 2 decades. Hoping @Vagabond and @Canuck from Kansas and the rest of our east coast members are able to snuggle in at home and wait it out.

Since the beginning of December, every day has been below normal temperatures here in the Poconos, not not by just a couple of decrees, average temp below normal has been 10 to 15 degrees. We have not been above freezing since before December began (average highs are in the low 40's). We have about 4 inches of snow on the ground. It is supposed to warm up later in the week.

All that said, I prefer this to the torrent that you guys have been going through.

Stay safe and heed the warnings. Do not attempt to drive through flooded roadways etc (som some doing it in one of the clips posted, lucky they didn't stall out).

 

[509]

Yeah, I would feel sorry BUT.......when the east coast get very cold, we get nicer warm weather in eastern Washington.

I am sitting on my deck, at 60 degrees plus in the sunshine listening to Cajun music.

There are linkages in climate between California and Alaska as well.

Pretty interesting stuff, how weather at one end changes the weather at the other end.

 

[FinLuver]

To Matt's point -

An example of how parameters such as (100-year-flood) has changed we need look no further than the North Fork Stillaguamish. There are USGS flow records going back nearly 100 years (started in 1929). According to FEMA flood frequencies for the NF were -
10-year 28,100 cfs
50-year 30,300 cfs
100-year 31,100 cfs
500-year 32,100 cfs

In the first 50 years of the flow records available for that USGS site the above looks pretty accurate. The largest flow event prior to 1980 was 30,600 (about what the recent event was). Since 1980 there has been 23 flood events larger than that FEMA 100-year flood.

Since the Puget Sound Chinook were listed as threatened under ESA the North Fork Stillaguamish has had 14 flood events greater than that FEMA's 500-year flood (32,100) level. Further 9 of those floods were greater 39,000 cfs - 1,000-year events? The largest event has been 55,100 cfs, the new 100-year flood frequency? I suspect this is significantly larger than any seen pre-1980.

While we can debate how large a role climate change may have played in that dramatic change in the NF hydrograph, I doubt we can deny that it has played at least some role. The role of those increased flows changes on the basin's ecosystem is for another discussion.

Curt

What effects has logging the area had on water/soil retention or runoff?

 

[Matt B]

What effects has logging the area had on water/soil retention or runoff?

Hey! Look over there! Wow, did you see that?
So, got any holiday plans? How’s the missus?

 

[Matt B]

To make my point—
We’ve got one state agency that says the best available science is that water flows downhill and if you want to maintain water quality you need adequate riparian buffers all the way up even in the headwaters with no fish. They made this assertion at no small cost in economic and political capital. (WDFW)


We’ve got another state agency that says different size riparian buffers for different types of streams are a-okay, teeny little narrow buffers in the headwaters are fine, but that non fish bearing perennial streams do need a little bit wider buffers than they had been getting. (DNR)

And they’re getting sued by “industry.”

And there ya have it.

Edit- meant to post a link

WA forest groups sue over bigger riparian buffers - Chinook Observer

Washington timberland owners are suing three state agencies to overturn a rule that will prohibit logging within 75 feet of streams without fish in Western Washington. The rule will take 200,000 acres of timberland out of production, according to the Washington Forest Protection Association and...

chinookobserver.com

 

[Paige]

The washout on the NF Sky on Galena road is just below Troublesome creek campground and right above the bridge in that low spot, always wondered when that would go, another change down lower.

 

[SKYKO]

The washout on the NF Sky on Galena road is just below Troublesome creek campground and right above the bridge in that low spot, always wondered when that would go, another change down lower.

Thanks for posting this, I wasn't sure where the damage and changes were located on the N fork.

 

[Smalma]

What effects has logging the area had on water/soil retention or runoff?

It looks to me that the increased flows are a combination of impacts from both climate change and land use (logging in the case of the NF Stillaguamish). There is some debate which of the two play the larger role. There seems to be significant variation between basins the impacts.

In the case of logging a dominate factor maybe the density of roads and the run-off of those roads. It seems to me that increased flows associated with climate change amplify the problems in timber lands.

curt

 

[Paige]

 

[Otisdog]

I saw some massive trees floating in Saratoga Passage yesterday.

 

[wanderingrichard]

Anyone from the forum impacted and in need ?

 

[Zak]

Anyone from the forum impacted and in need ?

Great question!

 

[JudyM]

At the request of the Washington Emergency Management Division, the Oregon Department of Emergency Management has deployed a six-member swift water rescue team from Clackamas Fire District to assist with life-safety operations. The team deployed on December 11 for a seven-day mission in affected communities.

 

[Pink Nighty]

It looks to me that the increased flows are a combination of impacts from both climate change and land use (logging in the case of the NF Stillaguamish). There is some debate which of the two play the larger role. There seems to be significant variation between basins the impacts.

In the case of logging a dominate factor maybe the density of roads and the run-off of those roads. It seems to me that increased flows associated with climate change amplify the problems in timber lands.

curt

I imagine having a few hundred thousand additional beaver ponds might have helped some of these rivers as well. Or access to more than 1% of their original floodplain without doing damage to people.

We've really screwed the pooch on our creeks.

 

[Paige]

Sunset Falls.

 

[Tallguy]

I imagine having a few hundred thousand additional beaver ponds might have helped some of these rivers as well. Or access to more than 1% of their original floodplain without doing damage to people.

We've really screwed the pooch on our creeks.

Beavers and beaver ponds are interesting, possibly both good and bad depending on where. I lived in Reno for a few years, and there, the beavers are considered potentially unhealthy for some of the rivers and creeks because they eat down ALL of the riparian vegetation, especially the cottonwoods and aspens when they are small that removes shade and structure and decreases large woody debris. This may be a factor in too warm rivers in the summer.

Without wolves and bears and coyotes and hungry and cold humans to keep their population more in check, it's possible there have never been quite so many beavers in NV and the eastern Sierra as exist today.

I never saw any data, and am not completely sure what the evidence looks like, but heard the above from a couple people who should know those sort of details.

 

[Stonedfish]

Anyone remember when the beaver dam broke out by Duvall? I remember driving through there shortly after it happened.
SF

 

[Matt B]

Anyone remember when the beaver dam broke out by Duvall? I remember driving through there shortly after it happened.
SF

Deer Creek.
Someone had been messing with that dam trying to lower the water level of the pond.

 

[Matt B]

Beavers and beaver ponds are interesting, possibly both good and bad depending on where. I lived in Reno for a few years, and there, the beavers are considered potentially unhealthy for some of the rivers and creeks because they eat down ALL of the riparian vegetation, especially the cottonwoods and aspens when they are small that removes shade and structure and decreases large woody debris. This may be a factor in too warm rivers in the summer.

Without wolves and bears and coyotes and hungry and cold humans to keep their population more in check, it's possible there have never been quite so many beavers in NV and the eastern Sierra as exist today.

I never saw any data, and am not completely sure what the evidence looks like, but heard the above from a couple people who should know those sort of details.

Interesting anecdote for sure. The Eastern Sierras are pretty different from our post glacial systems up here. Around here, beaver ponds can cause surface temperatures to rise in the upper layers of the pond, but the ponds can frequently be at least somewhat stratified with cooler water in the “deep,” and downstream water temperatures can often be cooler due to increased upwelling resulting from the upstream ponding forcing more water into the alluvial aquifer.

 

[Pink Nighty]

Beavers and beaver ponds are interesting, possibly both good and bad depending on where. I lived in Reno for a few years, and there, the beavers are considered potentially unhealthy for some of the rivers and creeks because they eat down ALL of the riparian vegetation, especially the cottonwoods and aspens when they are small that removes shade and structure and decreases large woody debris. This may be a factor in too warm rivers in the summer.

Without wolves and bears and coyotes and hungry and cold humans to keep their population more in check, it's possible there have never been quite so many beavers in NV and the eastern Sierra as exist today.

I never saw any data, and am not completely sure what the evidence looks like, but heard the above from a couple people who should know those sort of details.

Lake Lahontan - Wikipedia

en.wikipedia.org

Don't let the Ranch lobby fool you!

There used to be a LOT more beavers, on account of a lot more water. One might say the beavers likely caused all the water (or a significant amount of it) to be available to be retained by pleistocene lakes in the great basin, but their natural numbers can be a attested to by many a fur trapper!

Beavers, over any real time frame, cannot eat themselves out of habitat. If they do, they will die. They're not otters after all. And once they've died, those riparian areas would come right back.

The Humboldt and it's associated tributaries have underdeveloped, infant riparian zones because Nevada just recently realized you can't water cattle on a steam with no flow. You need nearly enough for fish to survive to have hundreds of thousands of cows to drink it dry but still live.

With many, many more beaver in the flood zone, that riparian zone would expand because beavers retain the water and spread it horizontally across that otherwise barren landscape. So instead of 50ft of riparian buffer, You'd have 100 ft, then 125, then more, because that's what beavers do. They can't help it.