Little Sawmill Highway 28 Culvert

Salmonid Habitat Restoration and Acquisition

Fish Passage Improvement
Project ID023 16 SA
Recovery DomainsInterior Columbia
Start Date01/02/2020
End Date05/31/2021
Last Edited10/21/2021
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The Little Sawmill Highway 28 Culvert, completed by the Lemhi Soil and Water Conservation District (LSWCD), replaced twin undersized culverts acting as a partial fish passage barrier to open passage to 0.8 mile of high-quality habitat for the benefit of Chinook Salmon and steelhead in Little Sawmill Creek and Indian Springs. The deteriorating culverts were replaced with a new open bottom culvert with natural streambed. During project development it was determined that a ford and a wooden headgate were within the project area and would need to be addressed. The wooden headgate had already been abandoned as part of PCSRF project 016 14 SA and was no longer a fish passage barrier; therefore its removal does not appear in the metrics. The open water ford present in the culvert project area was replaced with a small wooden bridge downstream; this action is captured in the metrics.

Bids to complete the project came in much higher than expected, in part due to Idaho Transportation Department (ITD) specifications for the state highway. This project was delayed twice due to not getting acceptable bids the first two times it was advertised. LSWCD requested assistance from the Idaho Transportation Department and received assistance in the form of cash of $100,000. LSWCD also requested additional funding from PCSRF and was granted an additional $161,000 in Amendment 1. The third bidding process resulted in an accepted bid. Amendment 2 granted a one month extension to complete the project.

Project partners included LSWCD (sponsor), Idaho Transportation Department, and the Upper Salmon Basin Watershed Program, and improved passage for juvenile fish between the Little Sawmill Creek Habitat Improvement Project (PCSRF 010 16 SA) completed by Trout Unlimited and LSWCD in 2019 and the Playfair Irrigation Project (PCSRF 016 14 SA) completed in 2020.

Project Benefit    

The Little Sawmill Highway 28 Culvert Project benefits the Lemhi watershed by replacing an undersized culvert which is a partial barrier to fish passage. Replacing the old undersized culvert with a natural bed surface open bottom culvert will improve migration in and out of the high-quality habitat for all life stages of Chinook Salmon and steelhead.


Metric Completed Originally
Fish Passage
  Barriers Removed
  Miles Opened .80 .80

Funding Details

Report Total:$478,535

Project Map


WS 1    

  • Worksite Identifier: WS 1
  • Start Date: 07/05/2020
  • End Date: 09/01/2020
Area Description
intersection of Hwy 28 and Little Sawmill Creek

Location Information

  • Basin: Salmon
  • Subbasin:
  • Watershed:
  • Subwatershed:
  • State: Idaho
  • Recovery Domain: Interior Columbia
  • Latitude: 44.848863
  • Longitude: -113.620138


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




  • C.0 Salmonid Habitat Restoration and AcquisitionY (Y/N)
    •      . . C.0.a Habitat restoration and acquisition funding 478,535.00
    •      . . C.0.b Length of stream treated/protected .10
    •      . . C.0.c
      Project identified in a Plan or Watershed Assessment
      NMFS recovery plan. (National Marine Fisheries Service. 2017. ESA Recovery Plan for Snake River Spring/Summer Chinook Salmon (Oncorhynchus tshawytscha) & Snake River Basin Steelhead (Oncorhynchus mykiss).
    •      . . 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 478,535.00
      •      . . . . C.2.b.1 Length of stream made accessible .80
      •      . . . . C.2.b.3 Type of blockage/barrier (LOV)
      •      . . . . C.2.b.4 Number of blockages/impediments/barriers impeding passage 2
      •      . . . . C.2.f.1 Culvert installed or improved at road stream crossingY (Y/N)
        •      . . . . . . C.2.f.2 Number of culverts installed or improved 1
        •      . . . . . . C.2.f.3 Miles of stream made accessible by culvert installation/upgrade .80
      •      . . . . C.2.g.1 Bridge installed or improved at road stream crossingY (Y/N)
        •      . . . . . . C.2.g.2 Number of bridges installed or improved/upgraded 1
        •      . . . . . . C.2.g.3 Miles of stream made accessible by bridge installation or improvement/upgrade .80