Soctish Creek Fish Passage Assessment and Design - Hoopa Reservation

Salmonid Habitat Restoration and Acquisition

Fish Passage Improvement
Project IDHOOPA-2019-1
Recovery DomainsN CA - S Oregon
Start Date01/01/2020
End Date09/30/2021
Last Edited04/24/2020
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4. Objective: Assess and redesign the diversion on Soctish Creek to re-establish anadromy above the diversion, or add a fish ladder if a redesign is not feasible.
5. Project Description: Feasibility assessment and design of a modified water diversion or the addition of a fish ladder on Soctish Creek to allow anadromous fish passage to an additional 6 miles of stream habitat. Allowing fish passage at impassable stream crossings is a priority action, as identified in the SONCC Recovery Plan ( Suitable salmonid habitat is available above the diversion; Hoopa Tribal Fisheries have captured age 1+ and 2+ Oncorhynchus mykiss above the diversion via electrofishing. SONCC Coho utilize Soctish Creek the 600 yards of stream below the diversion in most years, but have not been identified above the diversion. Designed to increase downstream water velocities for irrigation, the diversion is a concrete wall that creates a 2 foot plunge into the pool below. The top of the diversion extends back into the upstream pool, leaving emigrating fish with nowhere to land. Would-be spawners jump the fall, only to slide back down into the pool below. There is a side-channel at the diversion that could theoretically allow fish to bypass the diversion, but side channel flows are insufficient to allow upstream migration in most years. If redesign of the diversion is not an option, the seasonal side-channel could be modified into a fish ladder. This project involves coordination with the Humboldt County Public Works Department and NOAA Fisheries to scope alternatives that meet fish and water delivery needs in the most cost effective manner possible. Once the feasibility assessment is complete, a preliminary proposal/design will be developed for implementation.

Project Benefit    

Project Benefit: SONCC in the lower Trinity River are identified in the Recovery Plan as being at high risk of extinction. Restoration of tributary habitat for both natal and non-natal SONCC is therefore of great importance. Lower reaches of Soctish Creek provide year-round flows of cool water into the Trinity River. Both non-natal and natal juvenile SONCC as well as adults will be afforded free access to an additional 6 miles of suitable habitat consisting of pools, riffles and runs. Therefore, this project is expected to support increases in survival and growth of Coho as well as the other native anadromous salmonids.


Metric Completed Originally
Fish Passage
  Barriers Removed 2
  Miles Opened 5.10

Funding Details

Report Total:$82,125

Project Map



  • Worksite Identifier: 47007576
  • Start Date: 02/03/2020
  • End Date:
Area Description
Soctish Creek

Location Information

  • Basin: Klamath
  • Subbasin:
  • Watershed:
  • Subwatershed:
  • State: California
  • Recovery Domain: N CA - S Oregon
  • Latitude: 41.084743
  • Longitude: -123.713222


  • Southern Oregon / Northern California Coastal Chinook Salmon ESU
  • Southern Oregon/Northern California Coast Coho Salmon ESU
  • Northern California Steelhead DPS




  • C.0 Salmonid Habitat Restoration and AcquisitionY (Y/N)
    •      . . C.0.a Habitat restoration and acquisition funding .00
    •      . . C.0.b Length of stream treated/protected
    •      . . C.0.c
      Project identified in a Plan or Watershed Assessment
    •      . . C.0.d.1 Project Monitoring (LOV)
    •      . . C.0.d.2 Monitoring Location (LOV)
    •      . . C.2 Fish Passage ImprovementY (Y/N)
      •      . . . . C.2.a Fish Passage Funding
      •      . . . . C.2.b.1 Length of stream made accessible
      •      . . . . C.2.b.2 Square miles of streambed made accessible (Square miles)
      •      . . . . C.2.b.3 Type of blockage/barrier (LOV)
      •      . . . . C.2.b.4 Number of blockages/impediments/barriers impeding passage
      •      . . . . C.2.c.1 Fish passage blockages removed or altered (other than road crossings reported in C.2.f to C.2.i)Y (Y/N)
        •      . . . . . . C.2.c.2 Number of blockages/impediments/barriers removed/altered