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 actions were designed to protect aquatic resources in headwater reservoirs and rivers, while providing suitable conditions for anadromous species recovery in the lower Columbia River. The Mainstem Amendments were officially implemented in October 2008 (i.e., water year 2009) and have been in effect for 6 years. Previous research by Montana Fish, Wildlife & Parks provided empirical data and methods to assess potential impacts of dam operations, including power, flood control and flow augmentation. Historical river discharges and reservoir elevations, modeled physical habitat and biological conditions, gill netting data, and lotic fish population estimate data will provide an environmental baseline for comparison to the Mainstem Amendments. This project will use a combination of research and monitoring to compare the biological and physical responses of fishes and habitat to alternative 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 implemented in October 2008 and have been implemented for the past 6 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 during the productive summer months, while meeting established minimum flow requirements for species such as bull trout and providing tiered flows in the spring for 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 upstream and downstream of Libby and Hungry Horse Dams.
Montana Fish, Wildlife & Parks has 8 objectives in this SOW (2015-2016) for evaluating the Council's prescribed Mainstem Amendments on fisheries and habitat upstream and downstream of Hungry Horse and Libby Dams, Montana. Some objectives have been completed in the past and were deleted from this SOW, while other new objectives have been added. Some objectives will take several years to complete due to life history aspects of species under investigation and changes in environmental conditions resulting form changes to dam operations.
Objective 1 (WE C). Estimate annual and cohort survival rates of rainbow trout (i.e., Oncorhynchus spp.) in the Kootenai River where population estimate and age data are available and relate survival rates to environmental variables where sufficient data are present. Condition of various fish species will be evaluated to investigate long terms trends in condition for various sizes and species of fish and to assess the influence of dam operations on condition estimates.
Objective 2 (WE D). Continue to assess the current status of white sturgeon in Montana as a supplemental effort to ongoing recovery, habitat restoration, monitoring, and aquaculture activities in Idaho.
Objective 3 (WE E and F). 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, numbers in the Kootenai River downstream of Libby Dam.
Objective 4 (WE G). 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.
Objective 5 (WE H). 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 fish population metrics including fish condition.
Objective 6 (WE I). Assess catch rates, harvest rates, size structure of harvested fish, species composition of the catch, angler demographics, and angler effort on the Kootenai River downstream of Libby Dam and compare to previous estimates. A secondary part of this creel survey is to assess angler attitudes towards the current status of the Kootenai River, habitat conditions, and possible limiting factors and may include current dam operations, regulations, limiting factors, and potential mitigation efforts.
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. Coordination of staff in the Libby and Kalispell offices may be required for some work elements. All existing long-term monitoring sampling designs have been previously designed, but new field work may require new sampling designs to be produced or use common design for those types of data collection.
All data from fieldwork will be summarized depending on type of data and may include: population estimates, number of fish collected, length frequency histograms, weight-length relationships or relative weight calculations, species composition, dates of data collection, mean fish length by species, invertebrate metrics, angler effort, harvest, and catch rates, and summaries of dam operations including reservoir inflow, outflow, elevation, and water temperature. Statistical analysis will depend on what the data is used for and may include: calculation of a means, standard deviations, standard errors, 95% confidence intervals, use of linear , non-linear, and logistic regression analysis, and Analysis of Variance with post-hoc tests.