Priest River Coldwater Bypass Concept Science and Research

The Coldwater Bypass Concept would aim to restore and enhance 46 miles of Priest River by reducing summertime river temperatures to within suitable thresholds for trout. Learn more about the concept and its feasibility by reviewing the reports, below

2014: Portland State University Priest River Temperature Modeling

The study concluded that replacing 50-75% of the surface outflow from Outlet Dam with cold water from Priest Lake would result in suitable water temperatures for trout in roughly 46 miles of river from Outlet Dam to the mouth of the Priest River. View the final report

2019: Priest River Cold-Water Augmentation Alternatives Analysis Report

The study concluded that the preferred alternative based on diverse criteria was a gravity-feed system that relies on head pressure from Priest Lake to move water through a pipe to just below the Outlet Dam. View the final report

2021: Coldwater Bypass Concept Limnology Study Report

The study concluded that the coldwater bypass would not negatively affect water quality or limnology of Priest Lake. The study also suggested the bypass may improve conditions in the lake to reduce the likelihood of blue-green algae blooms. View the final report