Contract Description:
NOTE TO CONTRACT OFFICER: Send contract documents to Mike Burke, Administrative Contact and Matt Boyer, Supervisor.
Project Background
In 2003, the Northwest Power and Conservation Council (Council) directed the Pacific Northwest region to implement and evaluate a new dam operating strategy at several Columbia River dams. Beginning in the summer 2004, reservoir drafts at Hungry Horse and Libby Dams in Montana were supposed to be limited to 10 feet from full pool (elevations 3550 and 2449, respectively) during the months of July through September. During drought years, the reservoir drafts could be increased to 20 feet from full pool by September 30 at each reservoir. The Mainstem Amendment dam operation strategy also stabilizes water released into the South Fork Flathead and Kootenai Rivers by implementing hourly and daily limits on how quickly discharges could be increased or decreased on a seasonal basis. These Mainstem Amendment operations were designed to protect aquatic resources in headwater reservoirs and rivers, while providing suitable conditions for anadromous species recovery in the lower Columbia River and were officially implemented in October 2008 (i.e., water year 2009). Previous research by Montana Fish, Wildlife & Parks provided empirical data and methods to assess potential impacts of dam operations, including power generation, flood control and discharge requirements for various species including Kootenai River white sturgeon and bull trout. Historical river discharges and reservoir elevations, modeled physical habitat and biological conditions, gillnetting data, and lotic fish population estimate data will provide an environmental baseline for comparison to conditions under the Mainstem Amendments operating periods post-water year 2008. This project will use a combination of research and monitoring to compare the biological and physical responses of fishes and habitat conditions to prior dam operations upstream and downstream of Hungry Horse and Libby Dams, Montana.
Project Description
This project will assess the physical and biological effects of the Mainstem Amendment operating strategy at Libby and Hungry Horse Dams, Montana. The Mainstem Amendments were fully implemented in October 2008 and have been implemented for the past 7 water years. The Northwest Power and Conservation Council (NPCC) directed the region to test, implement, and evaluate new drafting limits and ramping rates at many of the dams in the Columbia River Basin. The new operation strategy limits the summer drafts of Libby Reservoir (Lake Koocanusa) to 10 feet from full pool (surface elevation 2449 feet) during normal water supply years and 20 feet (surface elevation 2439 feet) from full pool during the lowest 20% (i.e, drought) of water supply years. The Mainstem Amendments also limit the rates at which discharges into the South Fork Flathead and Kootenai rivers can be increased or decreased utilizing both daily and hourly limits depending on season and discharge level. These operations will stabilize flow in the rivers, while meeting established minimum flow requirements and flow augmentation for bull trout and Kootenai River white sturgeon. The new operating strategy may better mediate the needs of all resident fishes throughout the Columbia River Basin with anthropogenic needs including water supply, recreation, and hydropower generation. This project will use a combination of modeling and field research and monitoring to quantify and evaluate the effects of the interim operating strategy on the physical and biological communities and habitats upstream and downstream of Libby and Hungry Horse Dams.
Montana Fish, Wildlife & Parks has 8 objectives in this SOW (2016-2017) for evaluating the Council's prescribed Mainstem Amendments on fisheries and habitat upstream and downstream of Hungry Horse and Libby Dams, Montana. Work will take several years to complete due to life history aspects of species under investigation and changes in environmental conditions resulting from changes to dam operations.
Objective 1 (WE D ). Assess annual trends and changes to the biological communities and physical habitat conditions in Libby Reservoir. Metrics assessed include inflow, outflow, draft and refill rates, probability of refill, modeled primary productivity, fish condition and species composition,
Objective 2 (WE E and L). Assess annual trends and changes to biological conditions such as fish community indices and fish condition, and physical habitat conditions in the Kootenai River downstream of Libby Dam. Metrics assessed include fish abundance, catch per unit effort, fish condition, WETP, habitat area, seasonal and annual discharge, discharge variability, and water temperatures.
Objective 3 (WE F). Continue to assess and update the status of white sturgeon in Montana as a supplemental effort to ongoing recovery, habitat restoration, monitoring, research, and aquaculture activities in Idaho and British Columbia.
Objective 4 (WE C and G). Evaluate juvenile to adult survival of juvenile bull trout in Quartz Creek using PIT tags and a remote PIT tag station. Information on emigration and survival rates will be used to obtain a better understanding of life history and other factors affecting survival of bull trout and potentially, provide some insight into recent declines in bull trout redd counts and juvenile abundance estimates in Quartz Creek and the Kootenai River downstream of Libby Dam.
Objective 5 (WE H). Continue to monitor the seasonal dynamics of Didymosphenia geminata blooms using previously developed indices such as periphyton thickness and percent coverage and relate observed metrics to seasonal and annual dam operations and water quality data collected by the USACE.
Objective 6 (WE I). Compile and summarize data on the aquatic invertebrate community in the Dam-Fisher section of the Kootenai River, Montana to assess annual variability in invertebrate metrics including density, species composition, % EPT, biomass, and others. Annual changes in invertebrate metrics will be related to dam operations, periphyton metrics, physical habitat conditions, and water temperatures.
Objective 7 (WE J). Monitor D. geminata in the Flathead River and assess the impacts of water quality on mat formation
Objective 8 (WE K). Estimate juvenile to adult survival and emigration patterns of juvenile bull trout in several tributaries to the Flathead River to obtain a better understanding of potential life history and other factors affecting bull trout numbers in the drainage.
All Objectives in this statement of work require Environmental Compliance through BPA and scheduled data collection for fishes require Section 6 (bull trout) and Section 10 (white sturgeon) consultation with the United States Fish and Wildlife Service prior to this SOW and contract signing. All sampling and tagging to be performed in this SOW are in categorical exclusions under BPA including installation of the remote PIT tag station in Quartz Creek, which was installed in 2007. Maintenance of the PIT tag stations may require additional permits periodically, but annual USACE, MTDEQ, USFS, and other permit have been acquired through 2019, when the study is scheduled for completion. Coordination of staff in the Libby and Kalispell offices may be required for some work elements and sharing of data occurs frequently.
Field data will be summarized as population estimates, length frequency histograms, weight-length relationships or relative weight / condition calculations, species composition, mean fish length by species, invertebrate metrics (% EPT, biomass, densities) and summaries of physical conditions in the Kootenai River and Libby Reservoir including reservoir inflow, outflow, elevation, and water temperature.