Habitat Project

Project Area 3 - Floodplain connectivity and channel complexity maintenance enhancement

To address Tucannon River restoration goals, CTUIR placed large wood along 1.5 miles in Project Area 3 (river miles 46.7-48.2).

To address Tucannon River restoration goals, CTUIR placed large wood in Project Area 3 (PA3; river miles 46.7-48.2) of the Tucannon River during the summer of 2014. This restoration treatment had four objectives: 1) establish two key pieces (> 6m long, > 0.3m diameter) of large wood per channel width, (2) aggrade the channel, (3) reconnect the floodplain, and (4) increase channel complexity. After the initial restoration project in 2014, the number of pools in the restoration reach decreased and the number of side channels increased, which indicated channel aggradation within the reach. The number of key pieces of large wood also decreased below the target quantity. In 2017, CTUIR used the River Complexity Index (Brown, 2002) as a relative indicator of floodplain connectivity and channel complexity to assess how habitat conditions were changing since the 2014 restoration treatment. The RCI for PA3 increased between 2014 and 2017. Given the observed channel aggradation we hypothesized that RCI could be further enhanced by adding additional large wood in an effort to meet wood loading objectives for PA3. To complete the restoration design we used a vertol helicopter to add 350 whole trees with rootwads, 350 tree tops (racking material), and 30 ballast boulders. Large wood structures were designed to decrease stream velocities, aggrade the channel, and facilitate movement of surface water into existing paleochannels to increase floodplain connectivity. Using helicopters to place large wood in-stream reduced the time and money required to complete the restoration project, by decreasing costs for engineering design and permitting. As the river continues to work with the large wood structures over time, we anticipate additional increases in RCI (both in flood plain connectivity and channel complexity) which should result in habitat improvements for all life history stages of ESA-listed salmon species.

Project Lead: CTUIR

Project Collaborators: Washington Department of Fish and Wildlife, Snake River Salmon Recovery Board

First Foods this project targets


River Vision Touchstones this project targets

Aquatic Biota
Riparian Vegetation

External Links

Title Links
PA 3 2018 As-built Drone Video

Project Funders

Funder Funding Amount
Bonneville Power Administration$715,450

File Library

Title File Description
Final Project Design - 2018 PA3 Habitat EnhancementPA3 Final Design Drawings.pdfUploaded file PA3 Final Design Drawings.pdf
River Restoration NW Poster Presentation - PA3 RCI AnalysisPA3 RCI analysis poster final.pdfUploaded file PA3 RCI analysis poster final.pdf

Image Gallery

Title File Description
Project Area 3 LocationUploaded file PA3locationTucannon.jpg