Soldier Creek


Shasta-Trinity National Forest


Project Location: Soldier Creek is a tributary to the Trinity River, which flows into the Klamath River Basin in Northern Coastal California. Soldier Creek drains a watershed of about 12.6 square miles. The project sites were located within ¼ mile of each other with Crossing # 1 located on Evans Bar Road (County Road #414) and Crossing # 2 located upstream on Dutch Creek Road (County Road # 413) near Junction City, CA. The project area was located near the terminus of the Soldier Creek watershed where it meets the Trinity River. Crossing # 1 Lat/Long point is: 40°41’ 25.04”/123°01’ 40.86” and Crossing #2 Lat/Long point is: 40°41’ 25.29” / 123°02’ 10.09” of Sections 29 and 30 of T33N, R10W, MDB.

Link to the location of the remediated barrier in the CDFW Map Viewer (BIOS):

Project Description: The existing culvert at Crossing #1 was a 96-inch diameter (8-foot), 30-foot long corrugated metal pipe installed at a 2.98% grade with 4 ineffective railroad baffles. This crossing is located approximately 500 feet upstream of the confluence with the Trinity River. Crossing #2 also consisted of an 8-foot diameter, 51-foot long corrugated metal pipe set at 3.46% grade with four ineffective railroad baffles, located about 2,400 feet upstream of Crossing #1.
Pre-project conditions/barriers/challenges/background: Soldier Creek contains excellent habitat for coho salmon and steelhead.
Project actions/deliverables: Replace two road culvert crossings with clear spanning open bottom arch structures.
Fish benefits/ecological value: Allow access by Federally listed as Threatened coho salmon to about two miles of their Federally designated Critical Habitat, and steelhead spawning and rearing habitat, contributing to the overall restoration of the Trinity River and its fishery.
Other benefits:

  • Allows for 100-year flood flows and associated bedload and debris to pass safely through replacement structures.
  • Prevents future culvert failures.
  • Reduces maintenance costs associated with storm flows and culvert plugging.
  • Eliminates the potential delivery of over 1,350 cubic yards of sediment into the downstream reaches of Soldier Creek and the Trinity River.

Amount of habitat made available as a result of project implementation: 2.1 miles.
Habitat quality and type characterization: Spawning and rearing habitat for steelhead and coho salmon.
Project partners: Trinity County Department of Transportation, California Department of Fish and Wildlife, State Coastal Conservancy, American Rivers, Pacific States Marine Fisheries Commission, National Fish and Wildlife Foundation, 5 Counties Salmonid Restoration Program.
Project cost: $639,578
Project start date: 2003
Project end date: 2005
Monitoring and evaluation: Spawning surveys for adult Coho salmon occurred in early and mid-November 2005 after project implementation with no adults or redds located. Since project completion, several winter storms have hit the Northwestern part of California, causing major flooding and road failures on County and State roads. The structures at both Soldier Creek crossings were monitored during these events and problems with flooding and debris loading that had occurred in past events were not witnessed. The USFS will continue to monitor Soldier Creek for spawning activity over the next 10 to 20 years. The 5C Program will conduct post project monitoring for the next three years, including: spawning surveys, photo monitoring of up and downstream conditions, and inspection of the revegetation efforts. The TCDoT will monitor the structural integrity of the new structures for the next ten years.
Initial performance standards or goals: Remove two culverts on Soldier Creek that historically blocked access to about 2.1 miles of anadromous fish habitat upstream of Evans Bar Road in Junction City, California. The culvert structures did not allow for the passage of bedload and debris associated with high flows on Soldier Creek, and flooding at both sites was a common occurrence during winter storm events.
Did the project make a difference, and if so, how?

  • Providing 100% juvenile and adult salmonid passage to approximately 2.1 miles of upstream habitat during all flows where previous passage had been precluded by high velocities and >4-foot outlet jumps at the culverts;
  • Eliminating the potential for approximately 1,350 cubic yards of sediment delivery to the stream system and downstream Trinity River through removal of the culvert backfill material;
  • Increasing the flow capacities through the road crossings by allowing for unimpeded flow of the 100-year flows and associated bedload and debris while eliminating the potential for flooding, seen previously with the culvert structures;Preventing and minimizing the time and funds expended by the Trinity County Department of Transportation on maintenance and emergency efforts during high flow events to remove debris and implement clean-up efforts;
  • Implementing the Trinity River Record of Decision (ROD), by providing:
    • Sediment management, including the supplementation of spawning gravels below the Trinity River Dam and reduction in fine sediments, which degrade coho salmon habitat;
    • Watershed restoration efforts, addressing negative impacts which have resulted from land use practices in the basin.

Information posted on this page was obtained from the Final Report of the Soldier Creek Migration Barrier Removal Project.