In years past, the large accumulations of trees, logs, branches, shrubs and other woody debris deposited by floods that gave the Big Wood River its name were viewed by many as a hindrance to development and something that needed to be removed.
In fact, historic photos taken during the Wood River Valley's early development years show heavy equipment operating directly in the main river channel to root out the woody debris.
Times have changed, however, and today the importance of wood debris for a river's health is well known.
In what amounts to an about-face from those early years, the Hailey-based Wood River Land Trust is making plans to create both an "engineered log jam" and "bank barb" along the banks of the Big Wood River in Bellevue.
The bank barb will consist of several large logs submerged perpendicularly to the main river channel by large boulders. Bank barbs are used to deflect water flow away from sensitive areas and to create pool conditions.
Kathryn Goldman, project coordinator with the Wood River Land Trust, said strategically placing natural materials in the flood channel creates pool habitat and cover for fish, traps gravel that fish need for spawning, stabilizes the river channel and introduces additional nutrients into the aquatic system. Goldman said the organization hopes to complete the project by March, before high springtime flows commence.
The benefits of in-stream wood for fish are clear, Goldman said. "It gives them cover from predators, it gives them places to rest."
Goldman said the land trust chose the 12.57-acre Howard Preserve, located immediately west of downtown Bellevue, as the site for the demonstration project because of its easy accessibility and for the site's fairly benign hydrology. She said the land trust wanted to find a site that would not impact private properties. The Howard Preserve is a protected parcel managed by the land trust.
"We obviously wouldn't want to choose an area that would harm other property owners," Goldman said.
Accumulated cobble material that has built up in a secondary side channel will also be removed to provide greater floodplain connection, she said.
The Wood River Land Trust contracted with Bruce Lium, the owner of American Water Resources in Hailey, to design the project. Goldman said Lium has done a number of similar projects throughout Idaho on rivers including the Salmon. "He's a very experienced hydrologist," she said.
In a presentation to the Bellevue City Council on Tuesday, Lium said he's designed the logjam not as a completed structure, but as one he anticipates will promote additional woody debris to accumulate during higher springtime flows.
"The river can continue the work to finish the logjam," Lium said. "We feel the river has a much better knowledge of how to build these things."
Before the project can begin, the land trust will have to obtain the necessary permits from the appropriate regulating agencies.
The land trust is currently in the process of filing a joint permit application with the Idaho Department of Water Resources, the U.S. Army Corp of Engineers and the Idaho Department of Lands. They hope to have the permit application filed by Feb. 1. The Idaho Department of Fish and Game will also be reviewing the project.
