Little Rock Lake Nutrient TMDL

Little Rock Lake was listed as an impaired water by the Minnesota Pollution Control Agency (MPCA) on the 2008 303 (d) list. This Total Maximum Daily Load (TMDL) study addresses an excessive nutrient impairment in Little Rock Lake. The goal of this TMDL is to quantify the phosphorus reduction needed to meet Minnesota's water quality standards in accordance with section 303(d) of the Clean Water Act. Little Rock Lake is located in western Benton County. It lies within the North Central Hardwood Forest Ecoregion. The 67,650 acre watershed is nearly evenly split between Benton (36,030 acres) and Morrison (31,620 acres) Counties. The watershed land use is predominately row crops, with some woodland, grass/pasture and wetlands. Historically, Little Rock Lake resembled more of a wetland, but with the installation of the Sartell Dam in 1911, water levels were raised approximately seven feet. Today, Little Rock Lake's surface area is approximately 1,270 acres and is classified as a shallow lake. Little Rock Lake has a high value both as a recreational and shoreline development for it is one of two recreational lakes in Benton County.