Tucannon PA 13 Habitat Enhancement

WA Departmet of Fish and Wildlife (WDFW) proposes to restore 1 mile of the Tucannon River in the WDFW Wooton Wildlife Area and restore floodplain interaction to support ESA listed Steelhead, Spring and Fall Chinook salmon, and bull trout. Project Area 13 is highly confined due to past land use and flood control activities including channelization, levees, and a fish hatchery diversion dam. This has altered bedload and its transport within the project reach, resulting in a river starved of cobble and gravel. Subsequently, the loss of bedload has changed the dynamic interconnections of the river and its physical and ecological processes that support habitat diversity. Therefore, the focus of this project is to correct bedload losses and improve floodplain connectivity in the reach by adding gravel/cobble and building up the streambed with buried and partially buried large wood structures. This will be done using four large plug areas designed to lift the bed 2-3 feet in key areas. The plugs are engineered logjams buried with designed streambed mix, and then topped with small gravel. Restoration actions also involve removing levees that restrict natural floodplain connectivity and channel migration. Although some large wood is present, little is being recruited within the project area or transported from upstream; therefore, large wood will be placed throughout the channel. Gravel and cobble bars will be added to increase the amount of bedload in the reach and to interact with the new log structures. WDFW will also replant disturbed areas and enhance the in-tact riparian are with native plantings.

The goal of this project is to increase river complexity and floodplain connectivity for the purpose of improving adult holding, spawning and rearing habitat conditions for Snake River ESU spring Chinook and steelhead. This will be achieved by removng levees, adding wood and releasing gravels the have been retained by man-made structures.