Minnesota’s Threatened Rivers

Author: Josephine Marcotty | Published: 

– The mating dance of the hex mayflies drew John Sorenson to the Straight River at sunset.

As the bugs floated like snowflakes in the fading summer light, he pulled on his waders and waited patiently for the distinct sound of trout breaking the dark water to feed.

“It’s a treasure,” he said, stepping to the edge of the grassy bank and casting his line, as he has for years.

But the Straight River is becoming warmer and more polluted as farm irrigation rigs multiply along its banks. Now Sorenson fears that the fish huddling in the cooler deep spots are a stark sign that northern Minnesota’s only naturally producing trout stream is in trouble.

“In 10 years the Straight River could be a big muddy stream good only for carp,” he said.

And the peril is flowing downstream — into the Mississippi River and across a watershed that covers almost half of Minnesota, signaling a new and rising threat to one of the state’s great natural wonders. Like many others across Minnesota, the great river is heading toward an ecological precipice.

In the last five years, the Upper Mississippi watershed has lost about 400 square miles of forests, marshes and grasslands — natural features that cleanse and refresh its water — to agriculture and urban development. That’s an area bigger than Voyageurs National Park and represents the second fastest rate of land conversion in the country, according to one national study.

That breathtaking transformation is now endangering the cleanest stretch of America’s greatest river with farm chemicals, depleted groundwater and urban runoff. At this rate, conservationists warn, the Upper Mississippi — a recreational jewel and the source of drinking water for millions of Minnesotans — could become just another polluted river.

Here, around Park Rapids, potato fields are replacing forests, and drinking wells show rising levels of nitrate contamination from fertilizers.

Along the western edge of the vast watershed, soaring demand for irrigation is depleting sensitive aquifers and rivers that feed the Mississippi

And where the Upper Mississippi curves like a giant question mark through the center of Minnesota, many of its tributaries are showing signs of stress — phosphorus that breeds algae, sediment that makes the water cloudy, even bacteria in stretches farther downstream.

“What we do to our land, we do to our water,” said John Linc Stine, commissioner of the Minnesota Pollution Control Agency. Yet because most land use decisions are in the hands of private property owners and local governments, Minnesota has limited power to protect the river. “We can see it coming and still not be able to do something about it,” Stine said.

The battles over land use along the great sweep of brown river go beyond drinking water, to deeply held values that give the headwaters state part of its identity, said Bonnie Keeler, an environmental scientist at the University of Minnesota.

“Like clear lakes, stewardship, a sense of place and pride, and the identity of Minnesotans around clean water,” she said.

Quite beyond their sheer beauty, forested lands in the watershed also provide immense economic value in purifying drinking water for millions of people, an issue that has drawn the attention of federal regulators. This past summer, the U.S. Environmental Protection Agency launched a special project to predict how changing land use around the Upper Mississippi affects water quality, part of a larger effort to understand the threats facing major drinking water systems across the country.

Keeler, who directs the Natural Capital Project at the university and studies the social value of such things as clean water and forests, said it’s hard to find the right balance between protecting the Upper Mississippi and preserving economic engines such as agriculture and tourism. But, she added, the debate has thrust a new kind of environmental thinking to the forefront: Clean water, natural landscapes and wilderness have an economic value that deserves a place in the broader equation that defines a healthy economy.

In short, Keeler said, “What would a map of an ideal watershed look like?”

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