Status: In Progress

Location:

The project is located on Big Creek approximately 3.65 miles upstream from Big Creek’s confluence with the South Fork Coeur d’Alene River. The project is located with Shoshone County, Idaho. The coordinates of the project are 47.29’14.53 N, -116.03’49.48 W. The project is on Bureau of Land Management property and is adjacent to National Forest Road 264 and is downstream of the East Fork of Big Creek.

Background:

The project will improve fish passage within the Big Creek watershed and allow access to clean and cool habitat for westslope cutthroat trout spawning and rearing. Big Creek is the second largest tributary in the South Fork Coeur d’Alene River subbasin. The project will focus on the CSWD dam but will be complimentary to the downstream Sunshine Mine dam removal by removing fish passage barriers and opening approximately 13 miles of the Big Creek watershed. The dam removal will restore watershed function by returning the sediment and water balance and alleviating the stream channel incision occurring downstream of the dam. Water quality in the Big Creek watershed is in good condition (supported by Idaho Department of Environmental Quality (DEQ) Beneficial Use Reconnaissance Program (BURP)) electrofishing data and water quality data collected by applicant) and would provide refuge from the warmer and mine waste contaminated South Fork Coeur d’Alene River. Cutthroat trout and sculpin have been surveyed within the watershed (DEQ electrofishing data from 1998, 2011 and 2014).

The dam and associated water intake facility was used as the primary water source for a significant portion of the Silver Valley until a replacement facility was built in Enaville. In 2011, the CSWD water intake system was air-gapped to eliminate any potential contamination of the new facility and has not been utilized since that time. The dam is perched above the stream bed and has sheet piling driven to refusal in the center of its foundation. The velocity of the water passing through the spillway makes upstream fish passage impossible and the effect to the hyporheic flows (the mixing of stream water with groundwater within the streambed and its surrounding sediments) is unknown. Velocity increases over the dam as water depth and stream flows increase. During low flows of the summer and fall months, a pool exists at the bottom of the spillway, but the height of the dam is too great for fish to navigate. The bottom of the spillway is smooth and does not provide any roughness to reduce stream velocities or resting locations for fish or other aquatic species.

Removing the dam and restoring the natural dimension, pattern and profile of the stream will provide year-round fish passage. The 27 square miles above the project is located within the jurisdiction of the US Forest Service and the watershed above the project has very little development. Fish access to the entire Big Creek watershed would provide refuge from the warmer temperatures of the South Fork CDA River and provide clean spawning and rearing habitat.

Restoration Completed:

Funding was awarded in January 2026, project planning is underway.

Benefits:

The project will provide clean and cool refuge to fish from the warmer contaminated South Fork Coeur d’ Alene River. Removal of the dam will provide access to 13 miles of the Big Creek watershed that has been blocked from fish migration due to the height and water velocity created by the dam. Big Creek is the second largest watershed in the South Fork Coeur d’Alene River subbasin.

The uses targeted by this project are aquatic life uses including cold water and salmonid spawning uses. From Idaho water quality standards: cold water – water quality appropriate for protecting and maintaining a viable aquatic life community for cold water species. Salmonid spawning – waters that provide or could provide a habitat for active self-propagating populations of salmonid fishes.

Contact:

Rebecca Stevens
Coeur d’Alene Tribe
1031 N. Academic Way, Ste. 140 G
Coeur d’Alene, ID 83814
p: 208.667.5772
rstevens@cdatribe-nsn.gov

Sponsor:

Coeur d’Alene Tribe

Partners:

USFS, BLM, Central Shoshone Water District, Trout Unlimited Inc., Sunshine Mining/Silver Opportunities, and HMH Engineering