Every day there is more and more evidence that the beaver world has change and we’re not in Kansas anymore. But this ai article from the Economic Times takes the proverbial cake It discusses a recent study that somehow escaped my attention about beaver dams in urban creeks in Oregon. The study used modelling to examine their effect at mitigating flooding.
Yes, if you’re in Martinez and just cut yourself on the irony of that sentence, you are not alone.
The research proves that beaver dams in urban creeks can REDUCE flooding. Will someone please call our former mayor and let him know? I’ll be busy celebrating with friends.
Beavers don’t read engineering manuals, but it turns out their dams can do something engineers spend millions trying to achieve: slow down floodwater. A new U.S. Geological Survey study looked closely at two small urban creeks near Portland, Oregon, and found that beaver dams slowed down a significantly higher amount of water flow during storms than the same creeks but without dams. This did not stop the floods, but it certainly bought enough time to cope with the problem. For cities around the ..
Urban beaver dams helping cities? Everyone told me they were just problems…
The USGS researchers chose two urban streams from the Tualatin River Basin: Fanno Creek, which runs through a park in Tigard, Oregon, and Bronson Creek, located in a rapidly growing area of the same county. Both of these creeks have beaver dams. Computer models were developed for each stream. Two different scenarios for each storm were then run. In the first scenario, the beaver dams remained, while in the second scenario, the dams were virtually removed. This way, researchers could look at the. same storm impacting the same stream twice with just one variable changed: the presence of the dams. It’s a clean way to see what the beavers were actually doing.
Hmm interesting. So what happened?
The largest and intermediate storms saw Fanno Creek’s beaver dams storing an additional 914 to 1,249 m³ of water at its peak as compared to the no-dam version of the same creek. A similar scene was noted for Bronson Creek, where an additional 716 to 818 m³ of water storage was noted at the peak flows. The report also found that during small storms, both creeks would store a bit more water relatively because the ponds behind the dams had more empty space to fill up.
The findings point to a pattern. Beaver dams showed the greatest hydraulic difference at low and moderate flows. But as storms increased in size, the creeks still flooded their banks, and the floodplains themselves began to soak up water, dam or no dam.
TLDR: Beavers are helpful but they’re not gods. Their dams can slow things down in small or medium storms but in big floods they don’t make a difference.
The report is careful to note that its results are based on two small urban creeks of about a kilometer in length and shouldn’t be extrapolated too far. Larger streams, longer stretches, or multiple dams working together might behave differently. However, the study provides strong, model-based evidence for what conservationists have been saying for years: that allowing beavers to build in urban and suburban streams can create more diverse, slower-moving water habitats even if it doesn’t dramatically cut flood peaks.
Nature-based solutions aren’t magic wands. They’re just one small piece of a much bigger puzzle. Beaver dams won’t replace stormwater drains or flood walls. But they do slow water down, spread it out, and create wetter, richer habitats along the way.
Oh my goodness. Beavers matter and their dams help urban streams but they’re not gonna fix everything. Some of it you need to do yourself. I can’t think of a message I wanted to read more.
Here’s the study:
Finally CDFW is spending its money on the right thing. Click on the image to go watch it on their site. I grinned like an idiot throughout this entire thing and kinda teared up at the end. We’ve come so far. Watch it. Share with your friends. Share with your enemies.. Watch it again.
More like this please.
The new hit Pixar movie “Hoppers” is raising awareness and creating enthusiasm about the vital role beavers play in creating and protecting healthy and diverse environments.
But if these are your favorite critters, you can do more than just enjoy a movie. There’s a growing community of beaver fans joining the BeaverCorps! We’ll go to California to see the vital work they do protecting beavers, experience firsthand the training they go through, and share how YOU can become a member.
Beavers have definitely adopted a 50 state strategy – well 49 anyway, Here’s some great work going on in Michigan.
Beavers are returning to Michigan and damming up the place. Oakland University came up with a clever solution that allows us to co-exist alongside them.
Wasn’t that inspiring? Honeslly the reporter was more of a beaver believer than the college representatives at the end there…they seemed to tap out after saying beavers belong here and there’s ways to deal with them. They forgot: beavers save water, improve water quality, prevent flooding, increase fish density and diversity, remove nitrogen, reduce fires, increase bird diversity, and improve overall stream health.
Next time call us, we can offer some pointers.
This report arrived recently on the Scott’s river salmonid recovery and is full of encouraging things, But I especially loved the Michael Pollock quote. See if you can tell why:
Following the construction of the dams, one river saw juvenile coho salmon survival rates soar from 8% to 60%.
It’s well known that beaver dams transform landscapes. In their absence, artificial versions were built in northern California to recreate lost wetlands – boosting the survival of threatened coho salmon.
The findings are published in Frontiers in Ecology and Evolution. Fish biologist Michael Pollock of NOAA’s Northwest Fisheries Science Center called the results “mind blowing”.
Well, Pollock is the one who has been researching this all along, so if he says the results are mind blowing I think we should believe him.
With the beavers all but gone, in 2015 the nonprofit Scott River Watershed Council built two artificial dams on a tributary called Sugar Creek. Wooden posts were hammered into the streambed, interwoven with willow and conifer branches, then the gaps were plugged with gravel, straw and mud.
Three years later, several more dams were built on another tributary, called French Creek. From time to time, the remaining beavers even chipped in, repairing, modifying and sometimes expanding the dams. “When beavers do adopt a structure, their work is far superior to what we can accomplish,” says Charnna Gilmore from the Scott River Watershed Council.
Small, low-cost interventions yielded big, impressive results. But it’s bittersweet. “My take is that the artificial dams have helped people remember what the beaver can do and how integral they are to the health of stream ecosystems,” says Pollock. “But beavers can only thrive if landowners allow them to.”
