Lower Lemhi Rehabilitation

Salmonid Restoration Planning and Assessments

Restoration Planning And Coordination
Project ID010 07 SA
Recovery DomainsSnake River
Start Date06/03/2008
End Date03/30/2012
Year2007
StatusCompleted
Last Edited01/14/2025
 
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Description    


The original scope of the Lower Lemhi Rehabilitation project was developed to identify restoration alternatives for rehabilitating a relatively large segment of the lower Lemhi River. In 2007 the Idaho Department of Fish and Game (IDFG) identified a 2 mile section of river downstream of Hayden Creek that was degraded in the 1950’s. This segment contains long swift riffles containing little or no pools, side channel or lateral habitat, woody debris, and other complex habitat features that are important for rearing fish. In addition, this reach contains very large homogenous substrate that is not suitable for Chinook salmon or steelhead spawning. The purpose of the evaluation was to provide several alternatives for restoring some natural function to this reach of river by creating pools and other slow water habitats, developing lateral habitats where the stream margins and the riparian vegetation meet, and redistributing bed load material to provide suitable gravel for salmon and steelhead spawning.
In 2009 IDFG project managers coordinated with the Office of Species Conservation to modify the scope of work for this contract. Because of concerns by biologists with the feasibility of implementing a project of this scale, cost benefit analysis, and landowner concerns, other planning objectives were defined for this contract. The change in scope would focus on developing a design for an irrigation system that delivers decreed water rights for the ranch purposes while providing additional flow for fish in Bohannon Creek.
In 2010, additional coordination with the landowner and regional biologists revealed a renewed interest in the original Lemhi River project. Thus, the contract was once again modified to the original scope. Design alternatives would be developed to restore more than 2 miles of the lower Lemhi River segment. Coordination with engineers and the ranch continued for the purpose of meeting this goal.
Beginning in the fall of 2010 IDFG sub-contracted with an engineering firm to assist in completing the alternatives analysis. Contract staff engineers began processing LiDAR data and completing ground surveying to develop multiple options for re-establishing a new course for the existing river. Several meetings were held with the ranch during this period to gather input and help define areas of the ranch along the river that were unavailable for restoration work. Several iterations of design alternatives were developed and presented to the ranch. The engineering firm also worked closely with the IDFG to define habitat and fish conservation objectives.
The alternatives were completed. The proposed Lemhi River rehabilitation reach was divided into four restoration segments. Reach 1 is the uppermost segment extending from the L-10 diversion upstream approximately 0.75 mi. Reach 2 extends from L-10 downstream 0.40 mi. The lowest downstream segment is Reach 4, and it extends from the intersection of the Lemhi River and Highway 28 upstream approximately 0.60 mi upstream. Reach 3 extends from the upper extent of Reach 4, upstream approximately 0.75 mi. Three options were developed for each reach that vary from high complexity that maximizes habitat potential by taking advantage of the historic meander patterns of the river, to a more conservative approach that places greater emphasis on limiting the changes to the ranch lands and their operations (e.g. loss of pasture to a larger floodplain).

Design products developed under this contract will be used to determine the best options for rehabilitating the four proposed restoration segments. Coordination with the ranch will continue to select the best alternative for each segment. Habitat objectives, biological outcomes, and ranch operations and maintenance will be the primary considerations. Once the alternatives are selected, cost estimates will be developed and funding will be pursued for implementation of specific projects.

Project Benefit    


The product of the project will be the Eagle Valley Fish Habitat Assessment. This project will ultimately improve the conditions of spawning and rearing habitat for ESA-listed anadromous fish in the Lemhi River.

Accomplishments

Metric Completed Originally
Proposed

Funding Details

SourceFunds
PCSRF$19,303
Other$20,687
Report Total:$39,990


Project Map



Worksites

Lemhi River    


  • Worksite Identifier: Lemhi River
  • Start Date: 08/01/2008
  • End Date: 06/30/2012
Area Description

No Area Description data was found for this worksite.

Location Information

  • Basin: Salmon (170602)
  • Subbasin: Lemhi (17060204)
  • Watershed:
  • Subwatershed:
  • State: Idaho
  • Recovery Domain: Snake River
  • Latitude: 45.14353
  • Longitude: -113.72308

ESU

  • Snake River Basin Steelhead DPS
  • Snake River Spring/Summer-run Chinook Salmon ESU

Map

Photos

Metrics

Metrics
  • B.0 Salmonid Restoration Planning and AssessmentsY (Y/N)
    •      . . B.0.a Planning And Assessment Funding 39,990.00
    •      . . B.0.b.1 Area Encompassed 30.0
    •      . . B.1 Restoration Planning And CoordinationY (Y/N)
      •      . . . . B.1.a Planning and Coordination funding 39,990.00
      •      . . . . B.1.b.11 Engineering/design work for restoration projectsY (Y/N)
        •      . . . . . . B.1.b.11.a
          Name of plan implemented
          Idaho Department of Fish and Game, Eagle Valley Ranch - Lower Lemhi Restoration, Lemhi County, Idaho by Quadrant Consultants, Boise, Idaho
        •      . . . . . . B.1.b.11.b
          Description and scope of the plan implemented
          This project designed alternatives to rehabilitate a 2.0 mile reach of the Lower Lemhi River. The proposed reach was divided into four restoration segments. Reach 1 is the uppermost segment extending from the L-10 diversion upstream approximately 0.75 mi. Reach 2 extends from L-10 downstream 0.40 mi. The lowest downstream segment is Reach 4, and it extends from the intersection of the Lemhi River and Highway 28 upstream approximately 0.60 mi upstream. Reach 3 extends from the upper extent of Reach 4, upstream approximately 0.75 mi. Three options were developed for each reach that vary from high complexity that maximizes habitat potential by taking advantage of the historic meander patterns of the river, to a more conservative approach that places greater emphasis on limiting the changes to the ranch lands and their operations (e.g. loss of pasture to a larger floodplain). This design will be used to determine the best options for rehabilitating the four proposed restoration segments.