A new study by the National Academy of Sciences has found water quality in north Idaho’s Coeur d’Alene Lake is improving following efforts to mitigate pollutants flowing into the lake after decades of mining.
The recently released report analyzes current and historic water quality data and provides recommendations to preserve the health of the lake.
In 2020, the Idaho Department of Environmental Quality, Kootenai County, and the US Environmental Protection Agency, with the support of the Coeur d’Alene Tribe, asked the National Academy of Sciences to analyze water quality data in Coeur d’Alene Lake and provide recommendations to address issues of concern.
The study provided a third-party assessment of water quality data collected over the last three decades. The review focused on historic and recent trends in nutrients and dissolved oxygen in order to fully understand the state of the lake and identify the most appropriate protection measures.
To help kickstart preservation efforts, Idaho Governor Brad Little established the Coeur d’Alene Lake Advisory Committee in 2021 and directed $2 million for projects that reduce levels of phosphorus from entering the lake from wastewater, stormwater runoff, erosion, and other sources. The following year, the governor made available an additional $20 million for projects that support the state’s 2009 Lake Management Plan and reduce nutrient loading to Coeur d’Alene Lake.
