Sean C. Morgan
Humans from the South Santiam Watershed Council are taking cues from beavers and helping out the beavers and fish in Johnson and Morgan creeks, tributaries of McDowell Creek in the area of Speasl Road.
Watershed members noticed evidence of beaver activity last year, but they didn’t see anything active. This year they have, as beavers are busy damming up those tiny creeks. The Watershed Council has engaged in similar activity.
Trask Design of Corvallis, which specializes in watershed work, and Bio Services were busy last week placing 168 logs, 66 of them donated by Cascade Timber Consulting, which owns the property, into the two streams, a total of 29 logjams. The remainder are Douglas fir from a project to create oak savannah habitat in the Baskett Slough National Wildlife Refuge, west of Salem.
The Watershed Council found an old beaver flat upstream from the site of a structure, said Lance Wyss, project manager with the Watershed Council. “This year, there’s a new dam. We’re going to work with them and see if we can flood that flat again.”
“We’re trapping sediments so they don’t get washed out of that system. We’re basically creating a structure to back the water up.”
The idea is to fill up some of the low- lying wide spots in the banks and improve fish habitat.
The creeks mostly have resident cutthroat trout and a little rainbow as well as sculpin, dace and minnow, Wyss said. Steelhead may also be a possibility.
“These projects have multiple functions,” said Eric Anderson, Watershed Council coordinator. Fish habitat is definitely the key goal, but the water retention is important too. That helps recharge aquifers, and it slows down the water.
Water that starts moving too quickly cuts a narrow trench, which becomes a chute for high-pressure flows that wash nutrients downstream.
“What these log structures do is provide a coarse sieve,” Anderson said. The structures capture sediments and material and hold them in the stream.
The concept is similar to work done on Canyon Creek and on the Soda Fork of the South Santiam River, and another project coming up on Moose Creek in a partnership between the Watershed Council and U.S. Forest Service. Trees are tipped into the streams in those cases to help catch gravel and create spawning habitat. Tipping trees helps anchor the logs, especially during the winter when there are much stronger stream flows.
Morgan and Johnson creeks are much smaller, so the Watershed Council is able to use logs, which are threaded through trees and growth along the banks.
Anderson emphasized thanks to CTC.
“Letting us do this on their property is a big deal,” he said, noting that all of the Watershed Council’s work is voluntary for land owners.
The project is funded by a grant from the Oregon Watershed Enhancement Board and in-kind value from CTC, a total of more than $70,000.