This guest blog is from Beaver Friend and Watershed expert Brock Dolman of the OAEC. Brock was our guest speaker at the JMA Earth day event where he charmed us by saying that everything he learned about helping watersheds he learned from beavers. Here’s an exciting tale of what happens when folks get it right.
I had a spectacular beaver discovery day yesterday on the Klamath on a tributary called Boise creek just downstream from Orleans. I went out with fish biologist and restorationist Will Harling, who is also the director of the Mid Klamath Watershed Council.
This location on private land, with pro-beaver landowners who run an organic vineyard/winery operation, has had a long history of beaver being there. But it appears that this season this family group really got their groove on! From the photos you’ll see that they have, for what appears to be the first time (?), made a full dam across the main channel of Boise Creek that was about 4’ to 5’ tall. Consistent with their well deserved reputation as genius hydro-engineers, the location of this dam could not have been better chosen or constructed! When the instream pool is full, it now sets up the capacity to laterally divert a significant amount of water towards either bank and directly into the upper portions of a series of old historic flood channels and back water basins. And yet, the diversion is not so significant at this time of year as to really affect the bypass flows as can be seen from the falls at the mouth photo.
This “headworks” dam becomes the key to allowing the beaver to manage an ideal volume of diverted flow, which has created three major parallel contour terraces (each 1000’ or more long) that are made up of several dozen ponds and/or long linear sloughs and swamps. As these travertine type terraces, which make one visualize Balinese Rice Paddies, drop their elevation over smaller dams made of mud, grass and twigs it all ends up at roughly three primary discharge points that reconnect with the mainstem of the Klamath upstream of the Boise Creek confluence about an 1/8 of a mile or so.
From the fishery perspective this system was rockin!! With the use of my binoculars Will was able to peer into many pools, especially in the lowest terrace pool complexes that parallel closest to the Klamath, and see many hundreds of juvenile salmonids, with chinook, coho and steelhead all present!!! Besides their abundance, based on Will’s field experience, he felt that they all looked really healthy and comparatively extra large for their age class. In this area – it is hard to imagine a better rearing and refugia system for these threatened fish than what we witnesses yesterday! The MKWC and Karuk fisheries folks around here survey upwards of 60 tributaries for fish and finding places like this that appear to be able to hold so many fish, especially coho!!, appears to be critically important to a vision of coho recovery in this part of the system?
The coolest (literally) part about each of these points of river-reconnection is that they are low gradient and very easily passable slow water situations for juvenile salmonids that are rearing in the beaver pools above to head out or, hopefully allow entry for summer juv., salmonids looking for cold water refugia to escape from the hot mainstem? In essence they have created a braided series of delta channels with varying depth and velocity, which would appear to optimally allow for in and out migration passage of varying sized/aged juveniles?
See the one photo that shows the Klamath on the left with some sandy bottom and open willow areas with a small flow moving amongst them. This creek to river mouth access stands in stark contrast to where the primary Boise Creek mouth meets the Klamath which is a raging whitewater torrent over bed rock falls that is absolutely impassable to juvenile fish! See that photo for comparison.
Interestingly, from where the primary headworks beaver dam is on Boise Creek to the raging creek mouth is less than 100 yards of creek that appears to provide very little functional habitat for fish. But with the beavers pulling this proportionately small flow off the main creek and Slowing It – Spreading It – Seeping It for Salmon!!!, the actual total amount of newly accessible, way more productive and functional habitat that has been creating by the beavers is likely many orders of magnitude greater!! Ooh yeah- the neo-tropical migrant breeding bird songs and frog songs were thick around us the whole time as well! We need a grad student to work up & publish this whole beaver-re-storyation situation…anyone got such a eager student???
I want to say thank you to Will for being willing to spend that much time with me out of his busy life to go and witness such and inspiring and reinforcing situation. Always nice to find a place to enhance the feeling of more confident that our efforts to restore the reputation of beaver in CA as a friend of fish and people is a good path to being walking right now!!
From the front lines of Beaver-landia – over and out,
Brock
