Missouri River Basin Total Maximum Daily Load

This TMDL is a continuation of previously completed TMDL studies in the Lower Big Sioux River, Little Sioux River, and Rock River watersheds approved by the Environmental Protection Agency (EPA). In the Lower Big Sioux River Watershed, the Pipestone Creek Fecal Coliform and Turbidity TMDL (MPCA 2008) was approved in 2008. In the Rock River Watershed, the Fecal Coliform and Turbidity TMDL Assessment for the Rock River Watershed (Minnesota State University 2008) was approved in 2008. In the Little Sioux River Watershed, a turbidity and algae TMDL for Little Spirit Lake was completed by the Iowa Department of Natural Resources (IDNR) and approved by the EPA Region 7 in 2004 (IDNR 2004). At the time of this TMDL study, it was assumed that the Turbidity and Algae of Little Spirit Lake TMDL was applicable to Minnesota. However, during the preliminary review of this TMDL report, EPA Region 5 determined that the Turbidity and Algae of Little Spirit Lake TMDL is not applicable to Minnesota because Minnesota and Iowa have different nutrient criteria. According to EPA Region 5, Little Spirit Lake will require a TMDL. Due to this recent development, a nutrient TMDL for Little Spirit Lake will be deferred in the next 10-year watershed approach cycle and is not part of this TMDL report. This TMDL focuses on impairments of those three major watersheds (Lower Big Sioux, Little Sioux River, and the Rock River) in the Minnesota portions of the Missouri Basin.