The Minnesota River had been recognized as highly degraded and a significant sediment source filling Lake Pepin on the Mississippi River and delivering nutrients to the Gulf of Mexico. The Minnesota River Basin Reconnaissance Study, Section 905(b) Analysis recommended an “Integrated watershed, water quality management, and ecosystem restoration analysis, leading to the development of a basin scale watershed management plan” for the Minnesota River Basin.
The purpose of this Minnesota River Basin Interagency Study (MRBI Study) was to implement that recommendation by engaging agency partners and using advanced hydrologic modeling and environmental benefit analysis. The intent was to understand water, sediment, nitrogen and phosphorus transport across large landscapes to evaluate hydrologic, sediment and nutrient runoff response to historic, existing and probable future conditions.
The Minnesota River originates in southwestern Minnesota at the Minnesota-South Dakota border. It drains 16,770 square miles in Minnesota, South Dakota, North Dakota and Iowa. It flows 335 miles to join the Mississippi River at Mendota, Minnesota, just south of St. Paul and Minneapolis, Minnesota.
The study examined existing conditions of the basin and forecasted future conditions. The study integrates the efforts of local, state, federal and tribal agencies. Public involvement was conducted to ensure that the plan reflects the diverse perspectives of interested stakeholders.
The U.S. Army Corps of Engineers and the Minnesota Environmental Quality Board entered into a Feasibility Cost Share Agreement for the study on September 29, 2008. An interagency study team was formed to coordinate the study activities and oversee technical analysis of the basin.
The study team focused on detailed modeling efforts on sub-basins and from these models, scaled up the assessments to determine how various land and water management measures could be used effectively throughout the basin to reduce erosion, sedimentation, and flooding and improve water quality and habitat. The draft study report was completed in August 2019 and was formally approved in February 2020.
The Committee on Public Works of the U.S. House of Representatives authorized the study by a resolution on May 10, 1962, to determine the advisability of further improvements in the Minnesota River Basin for navigation, flood risk management, recreation, low flow augmentation, and other related water and land resources.
Federal Cost $4,520,000
Non-Federal Cost $4,520,000
Total Cost $9,040,000