Contract Description:
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 will increase 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.
Monitoring and habitat work conducted in this contract supports and complements in-stream restoration work done through Trout Unlimited in contracts 79310 and its predecessors, each of which are also contracted under project 2002-059-00.
The Yankee Fork Restoration Project has been collecting baseline data since 2006 and will continue to do so in 2019 through 2022. Water temperature data, juvenile abundance and distribution (via snorkel surveys), and invertebrate population data are collected at restoration sites and control (unrestored) sites in the basin. In the next four-year phase (2019 - 2022), topographic habitat surveys will also be done to monitor the changes at habitat restoration sites. Data collected for these surveys include water quality (water temperatures, pH, specific conductivity, turbidity, dissolved oxygen), discharge measurements, photo points, and invertebrate sampling.
Water quality and discharge measurements were recorded from 2006 to 2018 in the Yankee Fork Salmon River, tributaries and pond series side channels above, within, and below the six mile long dredged section. Discharge measurements from 2011 to 2017 on the mainstem of Yankee Fork Salmon River at the USGS gaging station indicate wide variability in flows in a short period of time, suggesting a very "flashy" hydrologic regime (a site minimum of approximately 32 cfs in March to a peak of approximately 3400 cfs in May/June). Water temperatures measured at 37 different sites in mainstem, tributaries, and pond series side channels in the watershed indicate relatively cool and consistent temperatures. Specific conductivity, pH, turbidity, and dissolved oxygen measured in previous years have generally fallen within acceptable levels according to federal standards for aquatic habitat.
The project has been working with the Yankee Fork Interdisciplinary (ID) Team to accomplish on the ground projects from 2012 to present. This coordinated effort will continue in this contract, building on restoration work accomplished at Pond Series Three Side Channel (2012), Pond Series Two Side Channel (2013), Preacher’s Cove (2014), large wood addition in the Yankee Fork between Jordan Creek and Eight Mile Creek (2015), Pond Series One Side Channel (2017), and the West Fork Confluence Area Project (2016-2017). At the upstream end of the dredged area, near Jordan Creek, the Bonanza City Project was begun in 2018 and is a two to three year phase project. The Yankee Fork ID Team plans on continuing with the Bonanza City Project in 2019 and 2020. Out-year planning to identify and prioritize projects for implementation through 2022 will continue through the ID team, building on needs identified in the Yankee Fork Tributary Assessment (2010) and developing a 5-year strategy plan under this contract.
The monitoring work done under this contract addresses habitat changes realized as a result of these restoration projects. Monitoring within these areas will help the team determine how improvements at these restoration sites have an impact on fish and habitat within the Yankee Fork Salmon River. Continuing to monitor restoration sites within the Yankee Fork basin helps determine the effectiveness of the fish habitat restoration projects and also helps inform future restoration needs.
Monitoring work done under this contract will continue to incorporate elements of the CHaMP monitoring protocol at a limited number (15) of sites. The Shoshone-Bannock Tribes have utilized the CHaMP fish habitat monitoring protocol in the Yankee Fork since 2013 and have developed a robust monitoring study design that helps inform restoration practitioners in the Yankee Fork basin. Data collected in the basin via CHaMP surveys (e.g., channel geometry, substrate, geomorphic units, temperature), paired with fish data (e.g., age class, abundance, and distribution), has improved understanding of fish-habitat relationships and adaptive management strategies in the basin over the years since restoration work began. Watershed Solutions Inc. has been helping implement the CHaMP protocol in the Yankee Fork for several years and will be contracted to continue this work in this contract.
Monitoring using CHaMP-type methodology will be continued for a maximum of one or two more years in the Yankee Fork basin as this phase of work in the basin wraps up. Project managers will work with BPA to define next steps and priorities for monitoring in the Yankee Fork in successive contracts.