Developing CE-QUAL-W2 Models of the Kootenai River and Koocanusa Reservoir, Montana and Idaho
Kootenay River looking upstream from survey vessel near Creston, BC.
Looking west across the face of Libby Dam.
USGS survey vessel conducting bathymetric surveys
The construction and operation of Libby Dam, a U.S. Army Corps of Engineers (USACE) project located in northwestern Montana, has altered the natural hydrograph, thermal regime, sediment transport, and nutrient loadings on the Kootenai River. Dam operation impacts riverine ecosystem function and many fish species, including the federally endangered Kootenai River White Sturgeon and federally threatened Bull Trout, as well as resident Burbot and other focal species important to a broad group of stakeholders in the region. Additionally, the ecological impact of increased trends in selenium and nitrate loading to Koocanusa Reservoir is of growing concern.
The U.S. Army Corps of Engineers (USACE) has identified a need to develop a numerical model of Libby Dam and Koocanusa Reservoir to help evaluate the water quality impacts of future operational changes on reservoir thermal properties, constituent transport, productivity, and trophic state. These water quality impacts ultimately influence temperature and nutrient loadings in the Kootenai River downstream of the dam. In response, the U.S. Geological Survey (USGS) is developing a CE-QUAL-W2 model to provide flow and temperature simulations, and potentially water-quality simulations, for Koocanusa Reservoir (Canada and US) and the Kootenai River downstream of Libby Dam.
To better understand the temperature and water-quality dynamics in Koocanusa Reservoir and evaluate structural and operational measures to optimize flow, water temperature, and nutrients in the Kootenai River for the benefit of Endangered Species Act-listed and other focal species, the USGS, in cooperation with the USACE is developing a CE-QUAL-W2 model of Koocanusa Reservoir and about 114 miles of the Kootenai River downstream of Libby Dam. CE-QUAL-W2 is a two-dimensional hydrodynamic model capable of modeling flow, temperature, and a large suite of water-quality parameters, which is optimized for the simulation of long, narrow water bodies that stratify. Phase I of the study (Fiscal Years 2023 – 2024) includes flow and temperature simulations for temperature management scenarios at Libby Dam. In future years, the USGS and USACE will explore expanding the Kootenai model capabilities to include water-quality parameters such as nutrients, dissolved oxygen, dissolved solids, organic matter, inorganic suspended sediment as well as selenium transport.
Monitoring Mining Effects in the Kootenai River Watershed
Evaluating Spatial and Temporal Fine-Scale Movement of Kootenai River White Sturgeon
Bathymetric Mapping of the Kootenai River
Assessing the impacts of mining on the Transboundary Koocanusa Reservoir
Kootenai River Sediment Studies
The construction and operation of Libby Dam, a U.S. Army Corps of Engineers (USACE) project located in northwestern Montana, has altered the natural hydrograph, thermal regime, sediment transport, and nutrient loadings on the Kootenai River. Dam operation impacts riverine ecosystem function and many fish species, including the federally endangered Kootenai River White Sturgeon and federally threatened Bull Trout, as well as resident Burbot and other focal species important to a broad group of stakeholders in the region. Additionally, the ecological impact of increased trends in selenium and nitrate loading to Koocanusa Reservoir is of growing concern.
The U.S. Army Corps of Engineers (USACE) has identified a need to develop a numerical model of Libby Dam and Koocanusa Reservoir to help evaluate the water quality impacts of future operational changes on reservoir thermal properties, constituent transport, productivity, and trophic state. These water quality impacts ultimately influence temperature and nutrient loadings in the Kootenai River downstream of the dam. In response, the U.S. Geological Survey (USGS) is developing a CE-QUAL-W2 model to provide flow and temperature simulations, and potentially water-quality simulations, for Koocanusa Reservoir (Canada and US) and the Kootenai River downstream of Libby Dam.
To better understand the temperature and water-quality dynamics in Koocanusa Reservoir and evaluate structural and operational measures to optimize flow, water temperature, and nutrients in the Kootenai River for the benefit of Endangered Species Act-listed and other focal species, the USGS, in cooperation with the USACE is developing a CE-QUAL-W2 model of Koocanusa Reservoir and about 114 miles of the Kootenai River downstream of Libby Dam. CE-QUAL-W2 is a two-dimensional hydrodynamic model capable of modeling flow, temperature, and a large suite of water-quality parameters, which is optimized for the simulation of long, narrow water bodies that stratify. Phase I of the study (Fiscal Years 2023 – 2024) includes flow and temperature simulations for temperature management scenarios at Libby Dam. In future years, the USGS and USACE will explore expanding the Kootenai model capabilities to include water-quality parameters such as nutrients, dissolved oxygen, dissolved solids, organic matter, inorganic suspended sediment as well as selenium transport.