Squaw Creek Culvert Replacement

The original proposed date for construction to begin was October 2006 with completion by December 2006. The project did not get off the ground until August 2007, due in part initially to cost share issues which resulted in contract delay and missing the field season work window. After cost share was attained and the contract and contract completed the construction was then delayed one week by wildfires and threats of possible evacuation in the area, but began August 13, 2007 as the fire condition subsided. Installation of the bottomless arch culvert was also complicated by manufacturers design flaws and a company representative was sent to the site to provide design modifications so the contractor could perform additional metal fabrication. The instream work and culvert installation was completed by August 27, 2007. Road access was thereafter available to residents living above the project site. Road resurfacing, guardrail and curb installation, and site re-seeding were then completed with minimal road traffic interference. Demobilization was complete October 4, 2007.

The culvert was replaced with a bottomless steel structural plate arch that is firmly secured to two pre-cast concrete strip footers. The culvert dimensions remained the same as proposed, 15.75 feet wide by 7.65 feet tall and approximately 40 feet long. The Squaw Creek channel slope was flattened to 6% starting about 30 feet downstream from the new culvert and extends upstream about 181 feet. The channel varies in width with a small 90-degree V-notch low-flow channel meandering across the bottom width. Rip rap scour protection completed up and downstream of the culvert and at the Papoose Creek confluence. The Papoose Creek channel was reshaped at a 12.5% slope extending approximately 130 feet upstream of the confluence. Isolated boulder clusters were placed in both channels upstream of the culvert for scour control and fish diversity. The areas affected by the construction were re-planted.

Steelhead trout, Chinook salmon, and bull trout will be able to access historically accessible, high quality spawning and early rearing habitat in the upper reaches of Squaw Creek. This project will be constructed after the barrier near the confluence of Squaw Creek with the Little Salmon River is removed. The Interior Columbia Technical Recovery Team (ICTRT) has identified one Chinook salmon population (SRLSR) in the Little Salmon River. Spring Chinook salmon were brought to the Little Salmon River in 1964 as mitigation for the lost run and fishery in the Snake River when the Hells Canyon complex of dams (Brownlee, Oxbow, and Hells Canyon) was constructed. The ICTRT has identified one population of steelhead (SRLSR) in the Little Salmon River and Lower Salmon. The Little Salmon River provides foraging, adult rearing habitat, and connectivity between local populations in the core area.