Rum River


The Rum River Watershed covers 997,060 acres in east-central Minnesota covering parts of Aitkin, Anoka, Benton, Chisago, Crow Wing, Isanti, Kanabec, Mille Lacs, Morrison,  and Sherburne Counties. The Rum River begins in Mille Lacs Lake and continues to flow 145 miles until it connects with the Mississippi River in Anoka. The Rum River Watershed contains 212 lakes and 233 stream segments. Land use in this watershed is comprised of agricultrual (39%), forest (24%), grass/shrub/wetland (18%), and water (15%). Major lakes in the watershed include: Mille Lacs, Onamia, and Borden. Major rivers and streams in the watershed include: Rum, Bogus Brook, and Mike Drew Brook.

The northern portion of the watershed is fairly healthy, as it lies in the Northern Lakes and Forest ecoregion, which generally has better water quality due to large amounts of forests, lakes, and wetlands. As the Rum River flows into southern Mill Lacs County, land use shifts to more intense land cover (agricultural and developed).  The middle portion has higher levels of phosphorus and sediment and contain the majority of the impaired waters. 10 lakes and 11 stream sections are currently  impaired.


The Rum River Watershed TMDL was completed in 2017 for dissolved oxygen, bacteria, and nutrients. While the impaired waterbodies lie primarily in Mille Lacs, Isanti, Sherburne, and Anoka Counties, contributing portions of the impaired waterbody watersheds extend into upgradient areas of Morrison, Benton, Kanabec, and Chisago Counties. Future implementation strategies to improve and protect local waters will require continued close cooperative efforts of all of the  Counties, Mille Lacs Band of Ojibwe, and local units of government.


The Rum River Watershed WRAPS was completed in 2017. The report concluded that the main issues in the watershed include:

  • Intensifying land use changes and their implications on increased runoff, sediment and nutrients throughout the watershed
  • Excess phosphorus causing algae blooms in lakes from both in-lake sources and from the watershed
  • High levels of dissolved phosphorus in the central portion of the watershed
  • Widespread issue of high E.coli bacteria concentrations
  • Physical habitat of aquatic macroinvertebrates and fish are being affected by various practices in the watershed

For more information on the Rum River Watershed, visit the MPCA website