The Yankee Fork River, historically a major Chinook salmon producer, has been severely altered by dredge-mining that occurred between 1938 and 1952, eliminating much of the natural meander pattern of the stream and associated in-stream habitat, riparian vegetation, and function. The restoration and monitoring work contracted under project 2002-059-00 is implemented with the goal of restoring natural river channel characteristics, floodplain function, hydraulic and sediment regimes, and aquatic habitat within the dredged reach of the Yankee Fork Salmon River (YFSR). The Yankee Fork Restoration Project focuses on restoring an approximately six mile section of stream habitat on private land in the Yankee Fork basin by removing or redistributing dredge tailings piles to restore or improve the connectivity of aquatic and floodplain habitat; by the addition of large woody debris, boulders, substrate, and riparian plantings to improve the complexity of aquatic and riparian habitat; and by creating or rehabilitating existing side channels.  Restoration work has been completed with goals of increasing the amount of aquatic habitat available and suitable for fish at all life stages, while at the same time reducing velocities to encourage sediment deposition for the continued improvement and maintenance of channel morphological complexity and floodplain soil conditions.  

The Yankee Fork Restoration Project has been collecting data since 2006, including juvenile abundance and distribution (via snorkel surveys) that takes about two weeks in July or August at restoration sites and unrestored sites in the basin. In 2020 topographic habitat surveys were conducted to monitor changes in habitat at the Bonanza site. This data can be compared to data at a later date to assist in determining any significant changes with moving large wood or depth of pools and number of pools, sediment deposition/aggregation, etc. Contract staff will collaborate with other Yankee Fork ID team members  (e.g., Trout Unlimited, Bureau of Reclamation) to assess fish presence, habitat use, and movement (e.g., passage success at the Bonanza project site), as well as assessing stream flows and groundwater dynamics through the Bonanza reach.  Data collected for these surveys will include discharge measurements and photo points. The project will also enter data collected from past years into a database and the Yankee Fork ArcGIS platform.

We will continue to work with the Yankee Fork Interdisciplinary (ID) Team in 2021. The Bonanza City project is at the upstream end of the dredged area, near Jordan Creek. It began in 2018 as a three year phased project. The third and final phase of instream habitat construction was completed in 2020. In August 2020, during base flows, adult fish passage and fall juvenile fish rearing passage were compromised as surface water subsided into the porous mine tailings, leaving less than 1 cubic feet per second (cfs) of streamflow in a 250-foot long section. It is anticipated that fish passage will remain compromised in 2021, as flows remain very low in the Bonanza project reach. In 2021, the Yankee Fork team will continue to work together to identify actions to address passage for migrating adult and juvenile anadromous and resident fish. Staff from this project will collaborate with project managers from the Trout Unlimited contract (also contracted under 2002-029-00) to identify adaptive management opportunities at the Bonanza project site.

Additionally, in 2021 the team will work on out-year planning to identify and prioritize projects for implementation through at least 2023. Contract staff have been working collaboratively with the Yankee Fork ID team to develop an Atlas planning and prioritization framework that incorporates fish and habitat data in the basin. This effort builds on past geomorphic assessments and basin planning documents (e.g., Yankee Fork Tributary Assessment [2010] and the 5-year strategy plan developed under the previous contract [Yankee Fork Habitat Restoration Plan, Yankee Fork Salmon River, Idaho, December 2019]) to help define the future direction of fish and habitat restoration in the Yankee Fork basin.