A new study paints a mixed picture of health for the Mississippi River upstream of the Twin Cities.
The upper stretch of the river is in pretty good shape, but the lower river needs large-scale changes to reduce pollution, according to the report out Wednesday from the Minnesota Pollution Control Agency
"The pattern that we found, is that the water quality in the Upper Mississippi, from the headwaters down to about the St. Cloud area, is really very, very good," said Dana Vanderbosch, manager of lake and stream monitoring with the MPCA. "But then, south of St Cloud, and into Minneapolis, the water quality really starts to degrade, and the river life isn't as healthy."
That northern stretch of the river flows largely through forests and wetlands that help filter out pollutants, but the lower stretch starts to receive a lot more polluted runoff from farms and urban development.
In fact, the Crow River, which flows through heavily farmed areas before it enters the Mississippi near the town of Dayton, doubles the nutrient pollution in the river, causing algae blooms and other problems.
That's despite the fact that the Crow River covers only about 15 percent of the total land draining into the upper Mississippi.
The river also fails to meet water quality standards for recreation and river life between St. Cloud and Minneapolis. That means it's not safe to swim in the river at certain times of the year, and it doesn't support as many fish and other aquatic life as it should.
To fix those problems, the MPCA says farmers need to add buffer strips to capture soil runoff, and do things like add cover crops, and optimize when and where they spread fertilizer and manure.
Those practices are largely voluntary. But Dennis Fuchs with the Stearns County Soil and Water Conservation District said farmers in his area are making changes.
"We've spent a significant amount of time working with producers to solve feedlot runoff problems," he said, "and to develop comprehensive nutrient management plans that help them optimize fertilizer and manure use."
Fuchs acknowledged the river is not meeting several water quality standards.
But in the Sauk River watershed near St. Cloud, he said, phosphorous and sediment levels have dropped.
"We've had significant improvement in water quality over time, because of conservation practices," Fuchs said.
While the challenge in the river from St. Cloud to the Twin Cities is to fix existing water quality issues, the priority near the headwaters is to keep that stretch pristine.
"We really have a rare opportunity to look at developing those watersheds in different way, where we can incorporate various strategies and best management practices as we're planning to develop those areas, so we can do this on the front end.," said Dana Vanderbosch of the MPCA.
The biggest threat to that stretch of the river, Vanderbosch said, is the conversion of forests and wetlands to farms and urban development.
Between 2008 and 2013, more than 260,000 acres of forest, wetland and grassland were converted to agriculture in the Mississippi River Headwaters area, according to the Nature Conservancy.
"We can't afford to lose these large swaths of forest wetlands and habitat in the upper reaches, because that's what producing our clean water," said Ron Biske, who manages the group's freshwater program.
The Nature Conservancy has helped purchase conservation easements in the area. Minnesota's Outdoor Heritage Fund has also helped conserve land.
But Biske said more needs to be done.
"From my view, I don't think Minnesota has done enough to protect this critical area of the state, to have a deliberate effort by the state and partners to protect critical areas for the river," he said.
The Mississippi River provides drinking water to 1.2 million people between the headwaters and the Twin Cities. As this study helps show, what happens in one section of the river, can have major impacts that flow downstream.