The Coeur d’Alene Tribe and Kootenai County announced a renewed five-year partnership Wednesday to monitor and protect the water quality of Lake Coeur d’Alene, the 25-mile-long glacial lake that serves as both a cultural centerpiece for the Tribe and the economic backbone of Kootenai County’s tourism industry. The agreement extends a collaboration that has been credited with preventing significant water quality degradation despite the region’s rapid population growth and increasing recreational use.
Under the partnership, the Tribe’s environmental science program and the Kootenai County Water Quality Division will jointly conduct monthly water sampling at 22 monitoring stations throughout the lake and its tributaries, sharing data and resources to track trends in nutrient levels, dissolved oxygen, temperature, and the presence of heavy metals from the lake’s legacy mining contamination in the Coeur d’Alene River basin.
Why Lake Water Quality Matters
Lake Coeur d’Alene is surrounded by the ancestral homeland of the Coeur d’Alene Tribe, which has managed the lake and its fisheries since time immemorial. The Tribe holds legal ownership of the lake bed under a federal court ruling and has treaty rights that include fishing, hunting, and gathering throughout the lake basin. For the Tribe’s approximately 2,500 enrolled members, the lake is not merely a recreation resource — it is a sacred and irreplaceable element of their cultural identity.
For Kootenai County’s non-tribal population, the lake generates an estimated $400 million in annual tourism revenue and supports thousands of jobs in hospitality, recreation, real estate, and related industries. Property values along the lakefront and in communities with lake access are directly tied to water quality — a decline in the lake’s clarity, fishability, or swimmability would have significant economic consequences for the entire county.
Legacy Mining Contamination
The Coeur d’Alene River, which feeds into the lake from the east, carries sediment contaminated with heavy metals — primarily lead, zinc, and cadmium — from over a century of silver and lead mining in the Silver Valley. The contamination, which extends from the headwaters near Mullan and Wallace downstream through the river delta into the lake, is the subject of one of the largest Superfund cleanup efforts in the nation.
The monitoring partnership tracks the movement of contaminated sediments within the lake and assesses whether cleanup activities upstream are reducing the flow of metals into the lake system. Tribal environmental scientist Dr. Laura Laumatia said the data collected over the past decade shows encouraging trends in some areas but continued concern in others.
“The lake is remarkably resilient, but it’s not invulnerable,” Laumatia said. “Our monitoring program gives us the data we need to detect problems early and respond before they become irreversible.”
What Comes Next
The renewed partnership agreement will be formally signed at a ceremony on April 10 at the Coeur d’Alene Tribe’s headquarters in Plummer. The public can access water quality data and monitoring reports through the Tribe’s environmental program website at cdatribe-nsn.gov/natural-resources. Residents concerned about specific water quality issues in the lake or its tributaries can contact the Kootenai County Water Quality Division at 208-446-1680.