When picturing the majestic and vast Boundary Waters Canoe Area Wilderness or the Superior National Forest, it’s easy to see them as distinct natural resources and valued recreational destinations. It’s harder to picture them as part of something even bigger.
At 2,954 square miles, the Rainy River-Headwaters watershed contains large portions of the Boundary Waters and Superior National Forest as well as much of northeastern Minnesota. Filled with vast tracts of upland and lowland forest, the watershed is dotted with 1,200+ lakes and 400 streams.
The watershed’s undeveloped nature — 85% is under state and federal ownership — is undoubtedly a key reason for the prevalence of high water quality. Because forests and wetlands dominate the landscape, monitored stream resources show exceptional biological, chemical, and physical characteristics. Most support a diversity of fish and wildlife species, habitat for aquatic and wild life, recreational opportunities, and timber production.
Overall, the watershed’s water quality conditions are good to excellent. The highest quality stream resources, based on aquatic life, habitat, and water chemistry are: Bezhik Creek, Denley Creek, Little Isabella River, Mitawan Creek, Snake River, Jack Pine Creek, Cross River, Moose River, and Stony River.
A limited number of impairments (meaning they do not meet state water quality standards) occur sporadically. They are typically limited to the lower reaches of stream and lake systems where likely human stressors from land use practices may accumulate. Stressor examples include historical and recent forest cover changes, urban/industrial development, and wetland drainage.
Results of recent Minnesota Pollution Control Agency research are included in the monitoring and assessment report: Rainy River-Headwaters Watershed Monitoring and Assessment Report (wq-ws3-09030001b)
Key impairments found in lakes and/or streams include high levels of sediment affecting water clarity, E. coli bacteria and mercury in fish tissue, likely caused by fossil fuel burning and airborne deposition.
- 15% of the 408 stream resources in this watershed were monitored and assessed to determine whether or not they supported a healthy fish and macroinvertebrate community. Two were impaired for aquatic life. 3% were assessed for recreation and one stream segment was impaired for aquatic recreation. These impairments were found on the Ash and Blackduck Rivers which flow to Kabetogama Lake and Voyageurs National Park.
- Biological monitoring results identified numerous sensitive fish and macroinvertebrate species in many of this watershed’s drainages and this is an indicator of good water quality.
- Several streams (Bezhik, Cross, Denley, Jack Pine, Little Isabella, Mitawan and Snake Creek / River) had exceptional biological communities that should be protected.
- All 245 monitored lakes, except for Blueberry Lake near Ely, had good-to-excellent water quality. The Blueberry Lake impairment was deemed to be a result of natural conditions.
In 2014, the MPCA began intensive watershed monitoring of this watershed’s surface waters, including Ash, Bear Island, Cross, Dunka, Dumbbell, Isabella, Island, Kawishiwi, Little Indian Sioux, Little Isabella, Moose, Shagawa, and Stony Rivers. The MPCA partnered with Cook and Lake County SWCDs and Vermilion Community College to conduct water chemistry sampling at 13 streams. The MPCA, Lake County SWCD, UMD’s Natural Resources Research Institute, the National Park Service, and local volunteers monitored 60 lakes. The results of the monitoring were used to assess all surface waterbodies for aquatic life, recreation and fish consumption (where sufficient data was available).