Sodom & Shearer Dam Removal and
Sodom Ditch Channel Reconstruction
November 7: Construction at the former dam sites is now complete. The bifurcation of Sodom Ditch and the Calapooia River has been reinforced with a large engineered log jam to purposefully deflect flow away from the bank and prevent erosion. Over 1500 feet of riverbed has been carefully constructed to seamlessly connect the bifurcation to the former site of Sodom Dam, which will allow for a properly functioning river conducive to fish habitat and bank stability. Some planting has occurred, with more scheduled for winter to re-vegetate the riverbanks.
|Sodom Ditch Project:
-Click photo to view album-
November 1: Willow were planted on a large engineered log jam at the bifurcation of the Calapooia River and Sodom Ditch. The log jam will properly deflect flow and prevent erosion, and the willow will help to stabilize this structure as well as provide crucial riparian habitat.October 26: With the riffles completed, the coffer dam has been breached and the river is once again free to flow down Sodom Ditch. Construction is now focused on creating vegetated soil lifts along the stream bank, as well as strategically placing engineered log jams and woody debris where appropriate. Vegetation is also being planted along the river bank to create a riparian buffer.October 24: Work continues to finish the bottom of the channel. The contractor is using fines (sand, clay, small gravels) from stockpiles on-site to seal the riffles. The fine materials are spread over the imported rock surfaces and tracked in. Then, the bucket of the trackhoe is used to drop water over the fine materials. The water transports the sand and clay particles and fills all the small spaces between the larger rock that comprise the riffle.Margin treatment work will continue along the Sodom, but the bottom of the channel is now sealed. Margin treatment includes installation of vegetated soil lifts, bank shaping, and placement of rock.October 6 – BONUS footage: Besides dam removal, the Council has been implementing a variety of other river restoration projects throughout the watershed. An example of this is the construction of several engineered log jams (ELJs) on the Castleberg property near Brownsville. Log jams strategically placed into an area of backflow off of the Calapooia River provide important habitat for endangered salmon species. View the photo album to learn more about the construction of these log jams and the importance of backwater habitat for river ecosystems.October 5: Work on the constructed riffles is nearing completion and the focus moves to the margin treatments including: installation of vegetated soil lifts (VSLs), large wood and alluvium rock matrix of rounded rock on the channel edges.Sodom Riffle Construction Week of 10/5 -Click photo to view album-Vegetated soil lifts are what they sound like – soil wrapped with jute fabric with willow cuttings placed on top. Each successive layer steps a foot and half closer to the bank and from the side view, resembles a staircase. Coir logs (made of coconut fibers) are installed in the toe of each layer to provide structure and stability to the lift. This bio-engineering technique provides bank stability by gently shaping the slope and installing a living bank protection (willow). The willow will slow down the river’s energy, trap sediment, and become deeply rooted, thereby protecting the bank from the river’s erosive forces. The VSLs are being installed with willow cuttings from the project vicinity. This vegetation will root in the coming spring and provide stability at the toe of the bank in areas where bare soil was exposed from project implementation. The coir logs and fabric wraps will provide short-term (3-5 years) stability until the willow become mature.Large wood jams are being installed on the margins of each riffle. These structures provide bank stability, cover for fish, habitat for insects, and slow water down because of their complex shape and structure, breaking up the River’s velocity.
September 28: Progress continues on construction of the riffles for the Sodom Channel Restoration Project. For the week of September 26th, work has begun on the margin treatments. This involves installation of wood material into the bench along the channel margin, along with willow clumps harvested from on-site. The final steps include placement of rounded rock which will be washed in with sands and fines. This restoration treatment is being implemented in the Sodom Channel just downstream of the bifurcation.September 20: Construction continues at the former site of Sodom Dam. Three riffles, designed by River Design Group and constructed by BCI Contracting Inc., will connect the bifurcation (where Sodom Ditch branches out from the Calapooia) to the dam removal site, resulting in a smooth gradient between the regions. Downcutting would occur if the riffles were not installed, which would result in increased water velocity, erosion, and poor habitat for fish and other wildlife.August 31: The removal of Shearer Dam was completed on Monday, August 29th. The project was implemented by Staton Company out of Eugene who were responsible for site access, site de-watering, concrete demolition, and channel restoration. The project site is on private property and does not have any public access. Removal of the dam took less than 2 weeks and was completed on budget. The channel restoration work included installing rounded rock material in the channel along with large, habitat boulders at the location of the former dam to stabilize the channel bed and provide some in-channel complexity.August 19: Images from the Shearer Dam deconstruction and fish salvage effort. The primary species targeted to be re-located downstream was the Pacific lamprey.August 11: Three turtles were captured in the riprap downstream of the coffer dam. Since they were in danger of being smooshed by the excavator as work progressed on the site, they were re-located out of harm’s way at the bifurcation.August 1st: For the next 2 months, the project will now focus on the more challenging component of the project: installation of the 3 grade control riffles to maintain the channel’s elevation to ensure water delivery to both the Sodom and Calapooia channels now that the dam is gone. The first step in this process has been to complete the site stake-out so that fill and excavation activities can begin to carve out the new channel. Creating the appropriate grade to begin importing the riffle matrix materials will begin this week. The riffle construction will begin at the downstream end of the site, at the former dam site.July 29th: Our Fish Passage Celebration was a great success! We’d like to mention a special thanks to the following people: Program Sponsors: Oregon Watershed Enhancement Board, Oregon State Parks, American Rivers, and National Oceanic and Atmospheric Administration. Contractors: River Design Group, BCI Contracting Inc., and Staton Companies. Event Sponsors: US Forest Service, Calapooia Brewing Company, and Wild Hog in the Woods. Event Coordinator and Volunteers: Whitney Smith, Kent Davis, Bud & Barbara Baumgartner, Eric Marble, and the OPRD staff at the Thompson’s Mills.July 25th: Coffer dam, clean water bypass installed, dewatering and fish salvage in Sodom Channel! Removal of the Sodom Dam was complete by noon on Friday, July 29th. Staton Company out of Eugene was subcontracted by BCI Contracting to remove the dam. The process went smoothly as the concrete of the dam itself was quite brittle with little rebar. The site looks completely different without the dam (or the water!) The 24-inch HDPE bypass pipe will stay in place until the construction is finished in 2 months. We are maintaining approximately 10 cfs of flow in the Sodom Channel downstream of the site during construction.Video- Sodom Dam Deconstruction (large file, 120 mg)