Written and photographed by Douglas Gayeton
EACH SPRING, THE MISSISSIPPI RIVER DUMPS A TOXIC BREW containing phosphorus and nitrate from agricultural runoff into the Gulf of Mexico, creating a eutrophic disaster the size of New Jersey. It’s the largest “dead zone” in the world, at times spreading across thousands of square miles, and it’s entirely manmade.
To learn how this happens each year, you might start by traveling a few hours northwest of Minneapolis, first passing St. Cloud and Sauk Centre on the 74, then continuing north across a sparsely populated landscape dotted with forests and native wetlands. Eventually, you will arrive at Lake Itasca, headwaters to the Mississippi River, and the second longest waterway in the United States. The water quality here is pristine, but one hundred miles later—where the Mississippi intersects with it’s first major tributary, the Crow River—everything falls apart.
What happens on Minnesota’s Crow River is a story that mixes good intentions, unsound practices, and benign neglect in equal measure, yet the troubles that plague this tributary are not unique. In fact, the story repeats itself on every tributary feeding the Mississippi as it winds through ten states on its way to Louisiana and the Gulf of Mexico.
By starting at the place where the Mississippi River’s troubles begin, we can learn not only how the Crow became contaminated but what people are doing about it. The story of the Crow teaches us that we all live in a watershed, and that our actions not only impact the people and fragile ecosystems where we live, but also those thousands of miles away.
To share the Crow’s story, we’ve embarked on a two-year journey focused on seven key themes. Together, they present an integrative approach to addressing future water challenges in a single dramatic arc, one that depicts the vital role waterways play and our responsibility in stewarding these valuable resources.
SOMETHING’S SERIOUSLY WRONG ON THE CROW RIVER, but it wasn’t always like this. Until less than a century ago, the Crow River flowed unimpeded through tall prairie grasses and a mixed hardwood forest of oak, sugar maple, basswood, and American Elm, which the bands of Dakota consider a sacred hunting ground. They named the Crow River “Hassan,” meaning “hard maple;” later, the Ojibwe tribe entered the area and renamed it after the crow, the “marauder of newly planted corn.”
Colonization by white settlers greatly altered the landscape: they converted prairie to farmland, drained wetlands, and cleared forests to build houses, towns, and roads. Today, the Crow River winds not through nature, but a patchwork of agricultural fields and small towns, under bridges, over dams, past levees, and through ditches. As the river makes its way to the Mississippi, it collects nutrient runoff from corn fields and feedlots, effluent from municipal sanitation services and rotting septic systems, and even chemicals used to de-ice roadways.
While the watershed may never be as pristine again, much can still be done to improve water quality on the Crow. Enthusiastic and committed nonprofits as well as state and federal agencies support each other in individual projects that combat the many threats to Minnesota’s waterways. The US Geological Survey (USGS) and Minnesota’s Department of Natural Resources (DNR) monitor the quantity of water moving through the river, while the Minnesota Pollution Control Agency (MPCA) tests for biological impairment by monitoring macroinvertebrates and native fish—like the walleye— populations in the river and its tributaries. The most important takeaway? The Crow River and the many lakes and streams within its watershed are seriously impaired by phosphorus, nitrogen, sediments, and dissolved oxygen. Simply put, the Crow River watershed is deeply out of balance. While paddling a canoe down the river, you see the signs everywhere. One visible threat are the pipes farmers install under their lands (tiles) to rapidly move rainwater off their fields and into nearby streams. This increased water flow accelerates shoreline erosion; trees fall into the water, banks collapse, and sedimentation increases in the river.
The North and Middle Fork Watershed Districts, along with the Crow River Organization of Water (CROW) monitor this steady degradation of water quality. Even citizens volunteer their time by collecting water samples for laboratory examination. They document floating blankets of white foam that signal an excess of phosphorus in the water, the clear signal of a habitat under siege. The Minnesota Dragonfly Society now pays attention to the river by conducting surveys of dragonflies and dragonfly nymphs on the Crow. By surveying the abundance and diversity of these apex predators, scientists gain a more holistic understanding of the river’s health; unfortunately, there aren’t many species left.
THE CROW RIVER FLOWS THROUGH several towns and cities. Under almost every street in Hutchinson, Atwater, Delano, Rockford, New London, Paynesville, and Watertown you’ll find a labyrinthian network of pipes. For drinking. For wastewater. Even pipes for stormwater. These pipes provide valuable benefits to city residents, but this aging infrastructure requires endless replacement and repair: nearly a third of all water pumping through these pipes is lost to leaks.
The Crow River watershed is also challenged by snowmelt and rain runoff that travels through ditches and pipes into nearby rivers. Unlike wastewater, not all stormwater runoff is treated before it empties into natural bodies of water. When rain falls on streets, roofs, and parking lots, it picks up pollutants that can include pesticides, fertilizers, oils, bacteria, litter, yard waste, and sediment, all of which get carried into nearby streams. De-icing methods used to clear snow off roads and walkways also produce chloride, or salt, that further contaminate waterways. After recognizing the environmental threat these pollutants pose, Minnesota has now begun monitoring stormwater runoff in towns across the state.
THE CROW RIVER WATERSHED IS PREDOMINANTLY AGRICULTURAL LAND. Rows of corn and soybeans border the river and its surrounding streams and lakes. When rain falls, especially in the spring and summer months, water tends to pool on farmlands, so a system using underground pipes (referred to as tiles, as they were once made from clay a hundred years ago) rapidly carry this water away to nearby streams and rivers.
While good for crops, tiles can wreak havoc on local waterways. A “flashy” river produces sudden, dramatic increases in water flow—often due to the efficiency of tiles in rapidly conveying water off agricultural lands. These sudden flow changes erode riverbanks and increase sediment loss, which greatly impacts water quality. Flashy waters also contain agricultural runoff—a toxic cocktail that includes nutrients from pesticides and herbicides, as well as fertilizers that contain phosphorus and nitrogen. These excess nutrients eventually flow from the Crow River into the Mississippi, then all the way down to the Gulf of Mexico. There, the sediments from agricultural runoff cause hypoxia, a condition where low or depleted oxygen levels create dead zones and die offs for fish and other aquatic life, resulting in significant losses for Gulf Coast fisheries each year.
In the face of these challenges, many Minnesota farmers have developed new practices to reduce and even eliminate nitrate and phosphorus runoff into nearby streams. Buffers, areas where natural vegetation grows between fields and waterbodies, are one approach to reduce runoff. Cover crops, reduced tiling, and other practices can also help keep soil on the land and out of nearby rivers, while organic practices that minimize or eliminate the use of chemical fertilizers, pesticides, and herbicides can also reduce impacts on the surrounding ecosystem. Lastly, using “precision” agriculture – the careful application of fertilizer, seeds, and water — can also reduce nutrients lost to runoff.
These practices, and the stewardship skills they require, will be necessary to help clean up the Crow, and may prove to be a model that other tributaries of the Mississippi River can follow.
CONFINING A LARGE NUMBER OF CATTLE IN ONE PLACE presents a number of environmental challenges. In the Crow River Watershed, one of Minnesota’s top livestock producing regions, 1,339 feedlots are registered in just the North Fork alone. That isn’t 1,339 animals. That’s 1,339 feedlots. And that isn’t the entire Crow River. That’s just one of its three forks. Each feedlot produces a significant amount of waste. Take pigs, for example. One hog can create as much waste in a single day as six to eight people. But unlike human waste, which is processed in multi-million dollar waste treatment facilities, animal waste is discarded in open pit lagoons, where it can sit for months before being sprayed on nearby fields. Because dairies and feedlots create many tons of waste, they have the potential to contaminate local waterways: with improper manure management, fecal matter can leach into groundwater or end up in lakes and streams, bringing with it bacteria, excess nutrients (phosphorus), ammonia, and suspended solids.
Soil and Water Conservation Districts, the MPCA, and the NRCS all work with farmers to install and regulate systems for manure management. These systems include infrastructure for storing manure, filtering water, and controlling the timing and placement of manure on crops.
However, not all feedlots and dairies are equal. With proper management, manure produced by cows, pigs, and turkeys can be stored for later use in ways that reduce water pollution and provide high quality fertilizer for crops, which saves farmers time and money. Properly managed waste can even produce a number of ecosystem benefits. Some intensive feeding operations are even putting their animals back on pasture. The animals are free to graze, and their waste is directly deposited on the soil, where it becomes a nutrient that improves soil health and provides even richer grazing lands for seasons to come.
A COLLECTION OF VORACIOUS, HIGHLY ADAPTABLE aquatic invasive species (AIS) that feed on nutrient-rich agricultural runoff threaten the state’s native ecosystems while having a significant impact on water quality.
When common carp appear in shallow lakes and wetlands, their foraging patterns dislodge shallow- rooted plants and stir up sediment that has settled on lake floors, releasing phosphorus, which then contaminates nearby streams and rivers.
Invasive eurasian watermilfoil and starry stonewort both grow as dense mats on lake surfaces, inhibiting boating and water recreation while outcompeting native aquatic plants for both nutrients and sunlight.
Curly-leaf pondweed, which has a unique life cycle that releases excess nutrients into the water each June and July, can create extensive algae blooms.
Another aquatic invader is the zebra mussel, now found in nearly 300 lakes and rivers across Minnesota. In five years, that number could double. Although they rapidly reproduce, these crustaceans won’t kill a lake. In fact, because they’re filter feeders—one mussel can filter nearly a liter per day—they actually make water cleaner. But the zebra mussel’s valuable ecosystem services come at a price. Filtering water also means absorbing vital nutrients essential to the livelihood of water creatures and forage fish: the more zebra mussels, the more imbalanced the food web becomes.
State agencies and lake associations spend thousands of dollars each year to educate the public about invasive species and clean and check boats entering and leaving lakes and streams. Unfortunately, it is mostly a losing battle. Still, residents have willingly taken up the cause, and there’s no shortage of inspiring stories on AIS eradication efforts across the Crow River Watershed.
THE CROW RIVER MEETS THE MISSISSIPPI near the town of Dayton, Minnesota. After twenty-four hours of travel it passes Fridley, where a filtration facility removes odors and bacteria from water, then stabilizes both its color and hardness before it becomes drinking water for Minneapolis residents. At every step, water quality is validated by nearly five hundred daily tests. The process monitors for the presence of e. coli, a fecal coliform that can cause human illness, employs spot testing sniffers at Minneapolis Waterworks, whose specially trained noses can test for contaminants—using methods perfected by sommeliers in the wine industry— before drinking water reaches the public. As companies develop new processes and products, the detection of trace chemicals used in their manufacturing revealed a major new threat to water quality: CECs. Even in minute amounts, these CECs (contaminants of emerging concern), which can come from agriculture, pharmaceuticals, personal care products, and even landfills, pose health risks that scientists have only now started to address.
At St. Cloud University, the effects of CECs that act as endocrine disruptors are studied using fathead minnows—fish with metabolisms similar to those of humans. The Minnesota Department of Health measures the presence of CECs in drinking water and studies their potential impact on human health and the environment. By learning more about these contaminants, municipalities will be able to develop new ways to filter them out of our drinking water, or, in some cases, even advocate for their elimination from public use.
THROUGHOUT OUR JOURNEY MAKING ON THE CROW, people continually ask the same question: “Given the now obvious global impacts presented by climate change, the challenges to maintaining water quality in our rivers and lakes, and the long-term environmental risks posed by current agricultural practices, are you still optimistic about our future?” Yes. Like many watersheds across Minnesota, the Crow River flows through an altered landscape defined by poor water quality and the increased risk of flooding, but through the dedicated efforts of a few state agencies and advocacy groups, work has begun to reverse this troubling trend. Farmers are now provided with technical assistance to implement management practices that keep soil on the land and out of local rivers and streams. Strategies for managing agricultural runoff—by both filtering it at the source and slowing it down before it reaches waterways—are also being put to use.
In other cases, farmers may even abandon the traditional planting of corn and soy in continual rotation in favor of new crops, including a wheat-like perennial grain named kernza, which was initially domesticated by the Land Institute in Salina, Kanasa. Today, the University of Minnesota has developed kernza as a perennial alternative to annual wheat crops, one that uses less water and fewer agricultural inputs while keeping the ground covered throughout the year as a hedge against soil erosion. By growing kernza instead of corn, agricultural runoff of harmful pesticides may also be reduced.
At Crow-Hassan Preserve, naturalists have undertaken prairie restoration initiatives to bring back tallgrass prairies. Wetlands in the region are now being protected and even expanded, and lakes are being drained to kill off invasive species, or cleaned up to remove excess phosphorus and other contaminants. Even families are getting involved, planting native flowers to attract pollinators and bring back bees. Restoring these landscapes, even with the simplest gestures, helps make surrounding waterways cleaner and brings them back into balance with nature. These efforts make us hopeful for the region’s future.
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