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The current concept would involve a hypolimnetic gravity withdrawal system, essentially a really long pipe that extends into Priest Lake and pulls cold water from far below the surface in the hypolimnion (deep, cold water in the lake), and replaces a portion of the lakes warm outflow with this cold water. The result would be much cooler water temperatures (up to 18°F cooler at the mouth and nearly 2°F at mile 45!) in Priest River, enabling coldwater fish species to live there all year.

Priest River Coldwater Bypass Alternatives Assessment IDFG 2019

To a trout fisherman this sounds like a great idea, but there were several concerns from the public about what a project like this could have on their beloved Priest Lake. Recently, IDFG hosted a virtual public meeting to discuss exactly that. In 2020 Advance Eco-Solutions did a limnological threat assessment of the proposed Priest Lake water release system and reported their findings there. They concluded that the proposed concept would have little to no effect on Priest Lake.

While it is still early and this is only a concept that IDFG is exploring, it does look promising. The Priest River in North Idaho could once again become a premier trout fishing destination. References Cited Berger, C., S. Wells, and W. Xu. 2014. Priest River Model: Model Development, Calibration, and Scenarios Report. Water Quality Research Group. Department of Civil and Environmental Engineer and Computer Science. Portland State University. Portland, Oregon. Isaak, D., S. Wenger, E. Peterson, J. Ver Hoef, D. Nagel, C. Luce, S. Hostetler, J. Dunham, B. Roper, S. Wollrab, G. Chandler, D. Horan, and S. Parkes-Payne. 2017. The NorWeST summer stream temperature model and scenarios for the western U.S.: A crowd-sourced database and new geospatial tools foster a user community and predict broad climate warming of rivers and streams. Water Resources Research. DOI: EPA (United States Environmental Protection Agency). 2003. EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards. EPA 910-B[1]03-002. Region 10 Office of Water, Seattle, Washington

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