Big Springs Lemhi River Confluence Restoration Project, P2

Salmonid Habitat Restoration and Acquisition

Instream Habitat Riparian Habitat
Project ID005 18 SA
Recovery DomainsInterior Columbia
Start Date11/28/2018
End Date09/15/2020
Year2018
StatusCompleted
Last Edited10/21/2021
 
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Description    


Phase II of the Big Springs Lemhi River Confluence Restoration Project improved 1850 of existing Lemhi River channel, as well as 4700 in Big Springs (1.24 mile total) through channel reconfiguration. Twenty pools were added, and 4.3 acres of floodplain were re-connected. Large wood structures were placed throughout the reach and 15 pools are expected to be created through scour. Riparian planting occurred on 2.48 miles of streambank and 0.6 mile of fence was installed to protect 3.4 acres. One water gap was installed.

Riparian exclusion was erroneously reported in the proposed metrics and was double-counted with the fence. During project development, the landowner requested a water gap; it was not in the proposed metrics. The 170 proposed structures to be placed in channel were over-reported as individual large wood pieces in the proposed metrics. The final metrics report the number of structures installed, which each consist of numerous large wood pieces.

Project Benefit    


The project will improve habitat for ESA-listed spring Chinook Salmon (Oncorhynchus schawytscha), summer steelhead (Oncorhynchus mykiss), and bull trout (Salvelinus confluentus). Project goals are to improve habitat for limiting life stages of ESA-listed fish, restore natural channel processes to maintain diverse habitat, and to address shade targets set in the Conservation Easement.The project aims to maximize short-term and long-term riparian and shade conditions to address established shade targets, reduce the channel width to a more appropriate geometry, increase in-stream hydraulic diversity and velocity gradients, increase pool size and frequency, increase interstitial space along margins, and increase in-stream cover. The design will increase sinuosity and add multi-threaded channel segments, narrow over-widened areas, and add in-stream structure to improve fish habitat and floodplain connectivity; excavate pools and create constrictions and place structure allowing the channel to maintain pools and a narrower, deeper channel while enabling a variable channel geometry; utilize existing mature riparian vegetation where feasible and appropriate to create immediate increases in bank structure, riparian conditions, and shade; and plant willows and sedges to enhance riparian conditions over time.

Accomplishments

Metric Completed Originally
Proposed
Instream Habitat
  Stream Miles Treated 1.24 .97
Riparian Habitat
  Stream Miles Treated 2.48 1.94
  Acres Treated 4.5 8.0

Funding Details

SourceFunds
PCSRF$383,426
Other$330,222
Report Total:$713,648


Project Map



Worksites

Confluence project    


  • Worksite Identifier: Confluence project
  • Start Date: 03/01/2019
  • End Date: 12/31/2020
Area Description
Big Springs and Lemhi River Confluence

Location Information

  • Basin: Salmon
  • Subbasin:
  • Watershed:
  • Subwatershed:
  • State: Idaho
  • Recovery Domain: Interior Columbia
  • Latitude: 44.729304
  • Longitude: -113.431818

ESU

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

Map

Photos

Metrics

Metrics
  • C.0 Salmonid Habitat Restoration and AcquisitionY (Y/N)
    •      . . C.0.a Habitat restoration and acquisition funding 713,648.00
    •      . . C.0.b Length of stream treated/protected 1.24
    •      . . C.0.c
      Project identified in a Plan or Watershed Assessment
      NMFS. 2017. ESA Recovery Plan for Snake River Spring/Summer Chinook Salmon (Oncorhynchus tshawytscha) & Snake River Steelhead (Oncorhynchus mykiss). Portland, OR.
    •      . . C.0.d.1 Project Monitoring (LOV)
    •      . . C.0.d.2 Monitoring Location (LOV)
    •      . . C.4 Instream Habitat ProjectY (Y/N)
      •      . . . . C.4.a Instream Habitat Funding 356,824.00
      •      . . . . C.4.b Total length of instream habitat treated 1.24
      •      . . . . C.4.c.1 Channel reconfiguration and connectivityY (Y/N)
        •      . . . . . . C.4.c.2 Type of change to channel configuration and connectivity (LOV)
        •      . . . . . . C.4.c.3 Miles of stream treated for channel reconfiguration and connectivity 1.24
        •      . . . . . . C.4.c.4 Miles of off-channel stream created through channel reconfiguration and connectivity .30
        •      . . . . . . C.4.c.5 Acres of off-channel or floodplain connected through channel reconfiguration and connectivity 4.3
        •      . . . . . . C.4.c.6 Instream pools created/added through channel reconfiguration and connectivity 20
      •      . . . . C.4.d.1 Channel structure placementY (Y/N)
        •      . . . . . . C.4.d.2 Material used for channel structure (LOV)
        •      . . . . . . C.4.d.3 Miles of stream treated through channel structure placement 1.24
        •      . . . . . . C.4.d.4 Acres of streambed treated through channel structure placement 1.5
        •      . . . . . . C.4.d.5 Pools expected to be created through channel structure placement 15
        •      . . . . . . C.4.d.6 Yards of average stream-width at mid-point of channel structure placement project3 (Yards)
        •      . . . . . . C.4.d.7 Number of structures placed in channel 34
      •      . . C.5 Riparian Habitat ProjectY (Y/N)
        •      . . . . C.5.a Riparian Habitat Funding 356,824.00
        •      . . . . C.5.b.1 Total riparian miles streambank treated 2.48
        •      . . . . C.5.b.2 Total Riparian Acres Treated 4.5
        •      . . . . C.5.c.1 Riparian plantingY (Y/N)
          •      . . . . . . C.5.c.2
            Species of plants planted in riparian
            Riparian plants used: Water Birch (Betula occidentalis), Bebb's willow (Salix bebbiana), yello willow (Salix lutea), coyote willow (Salix exigua), shrubby cinquefoil (Potentilla fruiticosa), Geyer's willow (Salix geyeriana), planeleaf willow (Salix planifolia), false mountain willow (Salix pseudomonticola), black cottonwood (Populus trichocarpa), chokecherry (Prunus virginiana), woods Rose (Roasa wodsii), cottonwood (Populus fremontii), Booth's willow (Salix boothii), serviceberry (Amelanchier) Herbaceous plants used: few-flowered spikesedge (Eleocharis pauciflora), northern grass-f-parnassus (Parnassia paustris), short-beaked sedge (Carex simulata), Nebraska sedge (Carex nebraskensis), tufted hairgrass (Deschampsia cespitosa), arrow-grass (Triglochin maritimum), arctic rush (Juncus Articus), golden pea (Thermopsis montana), Kentucky bluegrass (Poa pratensis), bluejoint reedgrass (Calamagrostis canadensis), tufted hairgrass (Deschanpsia casespitosa), blue wildrye (Elymus glaucus), fowl mannagrass (Glyceria elata), american mannagrass (Glyceria grandis), Aquatic plants used: monkey flower (Mimulus guttatus), watercress (Rorippa nasturtium-aquaticum), pondweed (Potamogeton vaginatus), hornwort (Ceratophyllum demersum), water buttercup (Ranunculus aquatillis), common bladderwort (Utricularia vulgaris)
          •      . . . . . . C.5.c.3 Acres planted in riparian 4.5
          •      . . . . . . C.5.c.4 Miles of streambank treated with riparian planting 2.48
        •      . . . . C.5.d.1 FencingY (Y/N)
          •      . . . . . . C.5.d.2 Miles of fence along stream .60
          •      . . . . . . C.5.d.3 Acres of riparian area protected by fencing 3.4
        •      . . . . C.5.e.1 Riparian exclusionY (Y/N)
          •      . . . . . . C.5.e.2 Acres of riparian area protected by exclusion other than fencing .0
        •      . . . . C.5.f.1 Water gap developmentY (Y/N)
          •      . . . . . . C.5.f.2 Number of water gap installations 1