Lake Pepin Watershed TMDL Eutrophication and Turbidity Impairments Project Overview

Lake Pepin has been placed on the 2004 list of impaired waters for two types of water quality problems. As a lake, it is impaired by excess nutrients that cause algae blooms, particularly severe during lower-flow periods. As part of the Mississippi River reach extending from the St. Croix River to the Chippewa River, Lake Pepin is also turbidity impaired. Lake Pepin is a natural lake on the Mississippi River. It has a surface area of about 40 square miles and a mean depth of 18 feet. Its watershed is about 48,634 square miles (approximately half of Minnesota's total land area plus a portion of Wisconsin), including the Upper Mississippi, St. Croix and Minnesota Rivers.