Contact: Cathy Rofshus, 507-383-5949
The upper Mississippi River, which starts at Lake Itasca in northern Minnesota, is in great shape until pollutants flow in from farmland and cities. By the time it reaches Minneapolis, it no longer meets water quality standards for river life and recreation. Results from a new study by the Minnesota Pollution Control Agency (MPCA) highlight the need to protect wetlands and forests in the iconic river’s northern areas while taking action to curb pollution in its southern reaches.
It’s hard to overstate the river’s importance as a drinking water source to millions of Minnesotans and Americans downstream.
The river is nearly pristine as it flows through forests, wetlands and lakes until the land changes to cropland and cities. South of St. Cloud, pollutants start to pour in with runoff, drainage and tributaries. These pollutants include sediment that clouds the water; nutrients that cause algal blooms; and bacteria that can make the water unsafe for swimming.
“What we do on the land is reflected in the water,” said MPCA Commissioner John Linc Stine. “This study underscores that point.”
The study shows the northern reaches of the upper Mississippi are healthy, thanks to the forests, wetlands and lakes that hold and filter the water flowing to the river.
“But these areas face increasing threats like forest or other land conversions for agriculture and development. Whenever land goes from a stable and vegetated state without protections in place, water quality will go down. That’s the lesson of history,” said Stine.
While the upper reaches need protection to keep the river healthy, the lower reaches need large-scale changes to reduce pollutants. After the Crow River flows into the Mississippi, phosphorus and nitrate pollution double in levels. The Crow drains a heavily farmed area and makes up about 15% of the total land area draining to the upper Mississippi in Minnesota.
“Thanks to groups like the Crow River Organization of Water, watershed districts, and soil and water conservation districts, work has already started to curb this pollution. But we all need to do more. We need more buffers, better use of fertilizer and manure, and more conservation on farmland and urban land,” said Dana Vanderbosch, manager of lake and stream monitoring for the MPCA.
The study also highlights the need to protect the upper Mississippi as a source of drinking water. Nitrate can make water unsafe for drinking. While levels are currently well below the threat level, water monitoring shows a trend of increasing nitrate levels, a concern for the 1.2 million Minnesotans who depend on the upper Mississippi for drinking water, as well as millions farther downstream.
It’s also important to continue efforts to decrease mercury levels in Minnesota waters. Mercury levels in fish and in the water in the entire upper Mississippi violate the consumption standard. This means guidelines will remain in place on how much and what size of fish to eat.
Many projects are underway at the state and local levels to ensure that the Upper Mississippi meets the standards for river life, recreation and fish consumption.
“The future health of the Mississippi River will depend on the ability of these projects to protect healthy conditions and reduce pollutant loads so that future generations can enjoy this invaluable resource,” Vanderbosch said.
About the study
As part of assessing the health of major watersheds across Minnesota, the MPCA studied the 510 miles of the upper Mississippi from Lake Itasca to St. Anthony Falls in Minneapolis. Scientists measured levels of pollutants such as sediment, nutrients, bacteria and mercury. They also studied populations of fish and other aquatic life such as insects. Using data from nearly 200 monitoring stations along the upper Mississippi, from many partners and spanning 10 years, the agency determined whether several sections of the river met water quality standards.
The agency and local partners conduct more detailed monitoring of the upper Mississippi, and the 20,105 square miles draining to it, at a smaller scale known as major watersheds. These watersheds are areas of drainage to tributaries or the Mississippi.
For more information, visit the Upper Mississippi River study webpage.