Low-Flow Characteristics of the Mississippi River
Upstream from the Twin Cities Metropolitan Area, MN, 1932-2007
Twin Cities metropolitan water supply planning is an ongoing issue. While most municipalities obtain their public supply water from increasingly stressed ground-water sources, the Metropolitan Council is investigating the option of using surface-water sources for future demand, in particular, the Mississippi River. Minneapolis, St. Cloud and St. Paul obtain all or most of their water from the Mississippi River and the question arises as to how much more water could be withdrawn from these main sources of water without going below the minimum threshold of sustained flow. Water levels are maintained in the Mississippi River in the Minneapolis and St. Paul area through a complicated array of upstream reservoir water releases and natural flow in tributaries to the Mississippi River. Understanding current water use needs and water management/release practices on the Mississippi River and its tributaries super imposed with drought conditions that have been documented in history is key to understanding water sustainability in the Twin Cities metropolitan area.
The Metropolitan Council, in cooperation with the U.S. Geological Survey Minnesota Geological Survey, characterized regional low flows in the Mississippi River basin above Anoka, Minn. and estimated the likelihood of extremely low flows in the Mississippi River near Anoka. A secondary objective was to describe the low-flow profile of the Mississippi River between the confluence of the Crow River and St. Anthony Falls.
Improved understanding of water sustainability in the Twin Cities metropolitan area, through improved understanding of water use needs and water management/release practices on the Mississippi River and its tributaries, super imposed with drought conditions that have been documented in history.