Why is the water always brown? How harmful can that be? County residents have always been interested in their water resources and to answer these questions and more Carlton County Soil and Water Conservation District, in partnership with Minnesota Pollution Control Agency, has begun work on the Deer Creek/Nemadji River Total Maximum Daily Load (TMDL) study. Previous watershed studies identified high turbidity and sediment as significant impacts to water quality. The result of these studies was to “list” Deer Creek and Nemadji River on the Federal Clean Water Act (303) d list of impaired waters. An impaired waters designation requires completion of a TMDL study.

Turbidity or cloudiness of the water, and high sediment yields can be detrimental to fish and other aquatic life, and in this case, even shipping! Sediment degrades the quality of the spawning habitat and turbidity can affect feeding success. High sediment loads from the Nemadji River have also been a major contributor to sediment buildup in the Superior Harbor. Historically, about 33,000 tons of Nemadji River sediment has been dredged annually from Lake Superior Bay by the U.S. Army Corps of Engineers to maintain adequate depth for shipping traffic.

The TMDL process will complete a series of steps to ultimately define a “load” or the maximum amount of pollutant (in this case sediment) that a water body (Deer Creek and Nemadji River) can receive and still meet state water quality standards. Sources of sediment are identified along with the amount of reduction needed. Strategies for reducing sediment will be investigated and described in an implementation plan. The eventual goal is to reduce sediment sources such that all contributions will result in Deer Creek and Nemadji River meeting water quality standards.

This year is the TMDL start-up year. Assessing and gathering up-to-date data is an important first step. Approximately 30 water sample events will be completed this season. Flow monitoring stations will be installed and provide a seasonal record of changes in water level and volume. We want to thank private landowners who have already given permission for access to sampling locations. Thank you for your support!

Public involvement in the TMDL process is important. We invite county resident’s questions, feedback and comments. If you see SWCD or MPCA staff working in the watershed, feel free to ask questions. This is a learning experience for everybody! Public meetings will be held in the future for more formalized discussions on the TDML process.

Please contact Kirstin Swenson, Water Resource Coordinator, Carlton SWCD if you have any questions or comments at (218)384-3891. Karen Evens is the MPCA project manager and can be reached at (218)725-7730 or via internet at karen.evens@pca.state.mn.us

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