We were approached by Terry Hansen who was concerned about his access road from farm to field in the winter of 2011. His concern was about the crossing’s collapsed culvert that was causing severe headcut erosion on the banks and creating a barrier for fish passage. This access crossed an unnamed seasonal tributary which flows directly into the North Yamhill River and has historically supported winter steelhead and cutthroat trout. This is the first obstruction on this tributary and is only a few hundred yards from the confluence of the North Yamhill. Upon my first visit to the site, it was clear that this obstruction needed to be removed. The upstream side of the culvert was partially collapsed causing water to be impounded upstream at normal flows and at high flows water overtopped the structure causing a 3 foot drop on the downstream side completely impeding migratory fish. In this visit, Terry told me what he knew of the structure and that the previous landowner had dumped the steel slag on both sides of the structure in order to stabilize the weakening crossing. The unnatural stream path was also causing head cut erosion both upstream and downstream and taking steel slag downstream at high flow events.
The District consulted with ODFW’s District Fish Biologist, Tom Murtagh. Tom came and electroshocked the downstream side of the obstruction in June 2011. After confirming that there were fish of concern using the reach and unable to pass the barrier we started to discuss options for removal and replacement of the obstruction.
There are several sources of funding that made this project successful. OWEB restoration grants are competitive grants available that will provide 75% cost share for work to improve watershed health. ODFW has a competitive fish passage grant program where they will provide 60% cost share on projects that implement fish screens and obstruction removal. Lastly, we applied for grant money that was available from the Newberg Chapter of the Association of Northwest Steelheader’s.
The project included removal of the collapsed and undersized culvert, concrete access bridge, and steel slag re-enforcement that was restricting steelhead, cutthroat and other fish movement into the unnamed tributary of the North Yamhill River Watershed. To replace the structure, we installed a full span bridge to address fish passage and meet landowner’s access needs. There were no other known obstructions and its removal would open up an estimated 6 miles of stream habitat.
The bridge was installed in July 2013 and was planted with native plants and shrubs in early October 2013 to eventually provide shade to this portion of the stream. This project could not have been possible without the support from our project partners, OWEB, ODFW and the Newberg Chapter of the Association of Northwest Steelheaders. Thank you again for your financial and technical assistance to improve Yamhill County’s streams for fish!