A new instream habitat project is set to be implemented this November in the mainstem Boise River – the first such project in decades and a top recommendation in the Boise River Enhancement Plan. The Boise River lacks roughness elements, such as rock and large wood, that provide habitat diversity, cover, and velocity breaks for fish. And like many sections along the Boise River, the project location site (pictured above) is wide and shallow. It’s great for osprey and eagles for fishing, but not so great for fish looking for a place to hide! The new project involves the installation of engineered rock and wood features within the main channel immediately downstream of Eckert Bridge but upstream of Barber Park put-in for floaters.
Because the project is being installed within the main channel, the design had to demonstrate that it would not increase flood risk, interfere with irrigation diversion or pose a safety threat to recreationists. In addition to large boulders, the design will include three sets of engineered log jams that will be submerged and anchored into the banks of the river. The logs will be placed so that they remain submerged year-round, providing critical habitat for fish during the winter when cover is scarce.
Post project construction, several areas along the banks will need to be revegetated with native plants, shrubs and trees. This is the perfect opportunity for a volunteer riparian enhancement project – keep a look out for an upcoming announcement from BREN!
BREN, in partnership with numerous stakeholder groups, advised on the type, design and location of the enhancement project. BREN hosted a site visit and project review for stakeholders in August 2016 and will organize the volunteer riparian enhancement opportunity. The instream habitat project is being funded by Ada County and Enel Green Power, and is being designed and implemented by the Idaho Department of Fish and Game.