Bonanza City Stream and Floodplain Project Phase I

Work began on the Bonanza City Stream & Floodplain Phase 1 project on June 18, 2018, preparing the project area for dredge tailings removal. During the 2018 and 2019 summer work windows, the quantity of dredge tailings removed was 90,185 cubic yards. An additional approximately 25,000 cy of dredge tailings were screened and sorted into cobbles, gravels, and fines, to be used for riffle, point bar, and glide substrate mixes in Phase II of the Bonanza City project. The sorted material was mixed and staged as part of Phase II. Much of the 0.83 mi streambank in the greater project area was treated with tailings removal as part of this process.

Work began on the 0.5 miles of stream habitat treatment on June 26, 2018 with tree staging for the project. Between June 26 and August 15, 2018, trees were staged in final locations using equipment available onsite and trees were added to stream using new equipment mobilized to site that meet the biodegradable hydraulic fluid criteria. In total, 15 large trees and 35 small trees were added to the stream at 6 locations to achieve instream habitat complexity objects. Bureau of Reclamation assisted TU with selected strategic locations that will scour and eventually move the river in new directions over time, helping with hydraulic diversity.

The ESA-listed populations that will benefit from the project include: Snake River Spring/Summer Chinook Salmon – Upper Salmon River MPG – Yankee Fork Population and Snake River Basin Steelhead – Salmon River MPG – Upper Salmon population. Chinook Salmon and Snake River Steelhead are known to utilize the project area for spawning, juvenile rearing, and as a migration corridor to access upstream spawning habitat.

Full benefits to fish won’t be realized until both Phases I and II of the project are completed.