Ranney Reach ELJ Project

Engineered Logjam Restoration

The historic removal of two hydroelectric dams in 2011-2014 returned the Elwha River to a free-flowing state, re-establishing upstream access for fish and other natural processes such as the downstream transport of sediments and large wood.

To help the river continue healing in its lower reaches, in Summer 2024 LEKT Habitat Restoration , Natural Systems Designs and BCI Contracting placed structures of large interwoven wood, designed to replicate natural features. This project recovers critical habitat for salmon that was lost over decades of industrial impacts and stabilizes features facilitated by dam removal.

Early 20th century development on this reach of the river included the construction of a railroad, bridge infrastructure and logging of the floodplain.

This project is a part of ongoing work to restore important salmon habitat in the Elwha River. Construction is complete and the recovered in-stream and side channel riparian areas have been revegetated. Read on to learn more about the process, signals of improving ecosystem health and more!

 

Project goals

  1. Restore a network of braided river channels
    • High flows concentrated in the main channel reduce the complexity of the river bottom, creating a channelized bed.
    • The main channel has migrated ~800’ west since 1939 (~10 ft/year), away from the side channels that provide slower moving water where juvenile fish can find refuge during high flow events.
  2. Increase the number of pools
    • Logjams form pools by diverting the flow of water in a river, creating a deeper area known as a pool; essentially, the logs act as a partial flow barrier, forcing water to pile up and create a deeper section behind them where adult salmonids can rest on their journeys upstream or juveniles can feed and hide before they enter the ocean. .
    • When the current encounters a logjam, it slows down and deposits finer sediments on the upstream side of the logjam.
    • As water flows around the logs, pulses of groundwater are also brought up to the surface, creating a cooling effect on the pools. This is especially important during low flows and hot weather.
  3. Create stable islands and banks where trees can mature
    • Revegetated island and eroded channel bank surfaces will maintain this in-stream complexity, with trees over time falling into the river and reinforcing an existing wood structure or creating a new one, in a continuous cycle.
    • Riparian vegetation also provides shade to keep pools cool, as well as a source of nutrients for streambugs, algae and periphyton.

→ These outcomes will interact over time to increase the extent and quality of juvenile habitat and spawning sites for the many anadromous fishes natal to the Elwha River:

      • Chinook, Coho, Steelhead, Pink, Chum, Bull trout, Cutthroat trout, Pacific Lamprey, and river-spawning Sockeye*

 

Approach

  1. Piling installation
    • Excavators are used as tools that can operate on the scale necessary to redistribute the substrate to fill in heavily channelized areas and install the pilings that will form the foundation of habitat structures.
      Credit: Tiffany Royal/NWIFC
  2. Managing the flow
    • Gravel bags and water pumps are used to temporarily divert flow away from construction areas.
  3. Protecting fish
    • Biologists use electrofishing technology to capture juvenile and adult fish so they can be moved to areas of refuge upstream of the installation work.
  4. Revegetation
    • 1,100 native conifers, 1,100 native shrubs and 1,000 native Willow and Black Cottonwood live-stakes are planted on the logjams and restoration site banks to provide the benefits of riparian vegetation (stream shading, wood inputs, insect and bird habitat).. The species planted were chosen based on presence in the locality, ecosystem services, and cultural significance.
Credit: Tiffany Royal/NWIFC

 

Check out this timelapse video of one of the habitat structures being installed!

 

 

Signals of recovery

  • Species trends
  • An active Chronolog repeat photo data series captures some of the floodplain reactivation occurring shortly after project completion to present. You can contribute images to this monitoring effort by visiting the site accessed from Crown Z Rd off Elwha River Rd (see map below). Check out the current time lapse of images here.
From the parking area beneath the bridge, it is approximately 0.6 miles one way flat, mostly paved walk through the state hatchery, past the public access gate to the levy and down a short dirt spur road to the restoration site viewpoint and Chronolog station.

 

Funding provided by

U.S. Fish and Wildlife Service

U.S. Environmental Protection Agency

Puget Sound Partnership

Northwest Indian Fisheries Commission

North Olympic Peninsula Lead Entity for Salmon

Washington State Recreation and Conservation Office

Salmon Recovery Funding Board

 

Additional Resources