Thermal Refugia Restoration and Observation in the Klamath River

Salmonid Research, Monitoring, and Evaluation (RM&E)

Project IDYUROK-2019-1
Recovery DomainsN CA - S Oregon
Start Date05/01/2020
End Date09/30/2021
Last Edited04/20/2022
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Project Objective: Conduct small scale restoration activities at selected creek mouths to enhance the physical parameters of associated thermal refugia and continue the long-term monitoring of salmonids at cold water refugia areas in the mainstem Klamath River using snorkel observations.

During this proposed project, the Yurok Tribal Fisheries Program conducted small scale restoration activities at selected tributary mouths aimed at enhancing the habitat within the associated thermal refugia. The size of these enhancements was dependent on the size of the tributary and its existing thermal refugia, however somewhere between 400 and 2000 square feet would encompass the size of most improvement areas. To achieve this goal, the Yurok Tribe used hand construction methods to improve fish passage into tributaries, and to install simple cover elements to thermal refugial areas. Tribal Fisheries personnel consolidated braided flow channels into a single coherent stream channel at Pecwan, Tully, Ke’pel Creeks and other creeks, and introduced simple cover elements at several of these sites as appropriate. Cover elements included dead brush and/or trees (where safe), which will not be permanently anchored. The changing and alluvial nature of these sites precludes the construction of permanent features. The SONCC recovery plan highlights the importance of thermal refugia to juvenile and adult coho salmon in the Lower Klamath River (volume II, page 18-14).
A secondary goal of the project was to to continue the snorkel observation monitoring that has been conducted for the past 15 years, monitoring that has demonstrated the importance of thermal refuges to both holding and rearing salmonids. Data collected added further detail to the multitude of snorkel observations already contained in the Tribe’s data set. All data collected will be compared to a range of environmental and biological river conditions. Temperature is probably the leading factor regarding salmonid thermal refugia use however other aspects of water quality may be involved.
In addition to juvenile salmonids, adult salmonids also make use of thermal refuges during times of elevated river temperatures. Snorkel observations also enumerated any adult fish that may be using this habitat feature. During past years the YTFP has documented many thousands of adult salmonids using the Blue Creek thermal refuge. This area is also known to be a critical location in observed outbreaks of the fish disease Ich (Ichthyophthirius multifiliis) and our snorkel observations can act as an early warning system for potential disease outbreaks. This is one of the most important aspects of this project. The YTFP has the ability to relay specific real time information to water managers regarding the abundance and health of both juvenile and adult salmonids using thermal refugia. This tangible result can be invaluable when dealing with disease issues on the lower Klamath River.

Project Benefit    

Project Benefit: This project will benefit Klamath River salmonids by enhancing critical thermal refugia habitat and allowing more salmonids to escape the elevated and lethal temperatures of the Klamath River. This benefit will be achieved by completing small scale physical restoration activities that will focus cool water to favorable locations and add structure to the area. This project will also be beneficial to salmonids by adding observations to our long term data set regarding salmonid holding and movements within thermal refugia areas. Another beneficial aspect of this project is its ability to provide real time data regarding salmonid congregations at thermal refugias to river managers.


Metric Completed Originally
Research and Monitoring
  Stream Miles Monitored 1.00 1.00

Funding Details

Report Total:$20,531

Project Map


Yurok Reservation    

  • Worksite Identifier: Yurok Reservation
  • Start Date: 06/01/2020
  • End Date: 09/30/2020
Area Description
selected tributary mouths on Yurok Reservation

Location Information

  • Basin: Klamath
  • Subbasin:
  • Watershed:
  • Subwatershed:
  • State: California
  • Recovery Domain: N CA - S Oregon
  • Latitude: 41.31644785383699
  • Longitude: -123.85487365722481


  • Upper Klamath / Trinity Rivers Chinook Salmon ESU
  • Southern Oregon/Northern California Coast Coho Salmon ESU
  • Klamath Mountains Province Steelhead DPS




  • E.0 Salmonid Research, Monitoring, and Evaluation (RM&E)Y (Y/N)
    •      . . E.0.a RM&E Funding 20,531.00
    •      . . E.0.b
      Complement habitat restoration project
    •      . . E.0.c
      Project identified in a plan or watershed assessment.
    •      . . E.0.d.1 Number of Cooperating Organizations 0
    •      . . E.0.d.2
      Name Of Cooperating Organizations.
    •      . . E.0.e.1 Number of reports prepared 0
    •      . . E.0.e.2
      Name Of Report
    •      . . E.1 MonitoringY (Y/N)
      •      . . . . E.1.a Monitoring funding 20,531.00
      •      . . . . E.1.b.1 Stream Miles Monitored 1.00
      •      . . . . E.1.b.2 Acres of Watershed Area Monitored 1,000.0
      •      . . . . E.1.c.2 Salmonid smolt or fry monitoringY (Y/N)
        •      . . . . . . E.1.c.2.a # miles (to nearest 0.01 mile) monitored for Salmonid smolt or fry 1.00
        •      . . . . E.1.d
          Name Of Comprehensive Monitoring Strategy/Program