Sauk River Chain of Lakes - TMDL project

This Total Maximum Daily Load (TMDL) study addresses nutrient impairments in 14 lakes of Sauk River Watershed, which is located within the Upper Mississippi River Basin above St. Cloud. These lakes do not meet Minnesota’s water quality standards due to excessive nutrient concentrations and nuisance algal blooms. The project area of 925 sq. miles (592,275 acres) is located in five counties of central Minnesota, with the majority in Stearns County. The impaired lakes are distributed along two converging flow paths: (1) the predominant Sauk River flowing from the north through the Sauk River Chain of Lakes (SRCL, 10 impaired lakes); and (2) the much smaller Eden Valley Creek flowing from the south through four impaired lakes and then into Horseshoe Lake, the most upstream of the Sauk Chain of Lakes (Figure 1). The goal of this TMDL is to quantify the pollutant reductions needed to meet state lake water quality standards for nutrients.

Sauk Chain of Lakes and Eden Valley Watershed Unit Flow Network (provided by William Walker). Click for larger image.

Map and location

Sauk River Horseshoe Chain of Lakes is located in the Sauk River watershed, which lies in the south-central portion of the Upper Mississippi River Basin.

TMDL report and implementation plan

Site-specific standards

PDF icon Sauk River Chain of Lakes site-specific standards (wq-iw8-38o)
  • Submitted to US EPA for approval on June 6, 2017
  • Approved by US EPA on February 12, 2020



  • Scott Lucas, Watershed Project Manager (218-833-9843)