Healthy headwaters: Upper St. Croix tributaries are mostly pristine — and need protection

Researchers reveal results of intensive study of lands and waters, sources of pollution, and recommendations for stewardship.




9 minute read

Kayaker in the Kettle River in Banning State Park (Paul VanDerWerf/Flickr)

Scientists have spent the last several years wading into streams and boating out to the middle of lakes to study water quality in the upper reaches of the St. Croix River watershed. They have returned to sites at different times of the year, analyzed samples in laboratories, and tried to figure out how everything is connected.

Their work came to fruition recently with the release of an extensive report on the Kettle River and upper St. Croix River watersheds. The publication includes information on the health of lakes and rivers in the region, the causes of problems, and recommendations for protecting these waters.

Led by the Minnesota Pollution Control Agency (MPCA), the effort also included local watershed districts and other experts. A public comment period on the draft reports is open now until Feb. 10.

The below slideshow of maps shows resources and concerns in the region. Click through to see all versions, click on any map to see it larger.

Located in eastern Minnesota, this region is home to mostly healthy lands and waters. Much of the landscape is covered in bogs, pocked by lakes, sliced by streams. It boasts numerous wild rice waters, which have likely been harvested by humans for hundreds or thousands of years.

“Streams of the Upper St. Croix Watershed are among the most biologically intact, healthy, and resilient of watersheds in Minnesota,” the MPCA says.

The research, publications, and public input are all part of keeping them that way.

The report shows how stewardship actions are needed to address current problems and prevent them in the future.

Wild waters

Wild rice growing on Kettle Lake in August 2020 (Photos courtesy 1854 Treaty Authority)

The Kettle River is a gem, one of just six in Minnesota with the state designation Wild and Scenic. It passes through two popular state parks, and is known for everything from giant sturgeon to whitewater kayaking. It drains more than 1,000 square miles.

The upper St. Croix is part of the federal Wild and Scenic River, managed by the National Park Service. This stretch is wild and remote, free-flowing, rich with life. It’s popular for multi-day canoe trips and fishing,

The drainage includes the Upper and Lower Tamarack Rivers, which flow from forested wetlands with abundant tamarack trees. The bogs give the St. Croix its tea-stained color.

This landscape provides valuable wildlife habitat and a source of clean water that feeds popular recreational stretches of the river.

Only about 25 percent of the Upper St. Croix’s watershed is in Minnesota, with the headwaters and most of the drainage in Wisconsin. The recent reports only cover the 500-square mile portion of the watershed in Minnesota.

Banning State Park (Michael Janke/Flickr)

Before European immigration to the area, and the arrival of logging, cities, and large-scale agriculture, the region was almost entirely forested. While much of it still wooded, providing priceless benefits for keeping the water clean, about 25 percent of the forest has been lost, now consisting of shrubs and grasslands, pastures, crops, and communities.

The rivers remain relatively clean, though. A state record lake sturgeon nearly six feet long was caught in the Kettle in 1994, holding the title until 2018, when a larger fish was caught on the St. Croix near Stillwater.

The Kettle enters the St. Croix at a confluence picketed by white pines, the water tumbling over rocks to make the final drop, carrying with it drainage from more than 1,000 square miles. It joins a four-mile side channel of the St. Croix called the Kettle River Slough, a side channel that features rushing rapids and stunning scenery.

From there it flows about 75 miles downstream to Stillwater, where the river becomes Lake St. Croix. That large and lovely body of water near the Twin Cities is plagued by too much nutrients, with work underway throughout its 8,000-square mile watershed to reduce runoff.

Nearly a third of the phosphorus that makes it into Lake St. Croix from Minnesota comes from the Kettle and Upper St. Croix. Plans to protect Lake St. Croix call for 15 percent reductions in phosphorus coming from these two drainages.

Improving conditions in the upper watershed could have positive effects far downstream.

Getting their hands wet

Conducting water quality assessment. (MPCA photo)

The MPCA measures water quality in many ways, but one of the primary methods is simply studying what lives in a stretch of stream. By sampling fish, bugs, plants, and other living things, scientists can tell if the water and the lands draining into it are healthy or not, supporting the full host of diverse life that naturally lives in the waters.

Based on extensive field surveys and analysis, the MPCA says the Kettle and Upper St. Croix watersheds are largely clean and healthy. They lay out strategies to keep them that way. And they point out a few problem spots.

“The reports are part of the MPCA’s approach to gauging the health of Minnesota’s 80 major watersheds, each of which will have an approved comprehensive watershed management plan by 2025,” the agency says.

The agency assessed 31 of the 126 lakes in the watersheds, finding that 18 meet standards for healthy waters. Others suffer from too much nutrients and the algae blooms that come with that problem.

The scientists assessed 78 stream reaches in the watershed, and found that a majority were fully able to support fish and insects, as well as human recreation. Twenty stream stretches are impaired for either impacts to fish and other aquatic life, or considered harmful to human health.

Rivers need to run

For the past century or so, humans have been hard at work trying to control the waters of this wet landscape. It was largely unsuccessful, and had negative effects on the health of rivers.

One of the biggest challenges facing fish populations are dams, culverts, and other structures that block movement. Numerous impediments are scattered throughout the network of tributaries, preventing fish from reaching spawning areas or simply surviving.

The Department of Natural Resources surveyed the watersheds in 2019, finding a total of almost 400 stream crossings of various types. Of those structures, 72 were identified as barriers to fish passage. They are identified as one of the “primary stressors” for stream stretches that are impaired for wildlife.

The Kettle River and its tributaries are home to lake sturgeon, a species of special concern in Minnesota, which need to migrate for to reproduce.

But two dams are already slated for removal in the watersheds. The Willow River dam was actually removed last month and construction of a rock rapids that will maintain water levels while allowing fish and other creatures to pass upstream. On the Grindstone River, the DNR is currently evaluating the possibility of removing a dam in the city of Hinckley.

Streams twist and turn naturally. They rarely run far in a straight line. But in the early 20th century, people attempted to straighten streams throughout Minnesota, primarily to increase drainage and dry out bogs and marshes. This included bogs areas in the upper reaches of the Kettle River watershed.

These straightened streams can create harm felt downstream. The water the channels quickly carry from peatlands to natural streams is low in dissolved oxygen — necessary for many forms of life, including fish. The MPCA says this source is “likely a major contributor” to low oxygen levels downstream.

Healthy water, healthy people

Canoeing the lower Kettle in St. Croix State Park. (Greg Seitz/St. Croix 360)

The primary problem facing streams in the region is “chronically elevated bacteria concentrations.”

Such bacteria can sicken people, causing everything from gastric distress to meningitis and other infections. High levels in lakes and streams are usually related to livestock or malfunctioning septic systems.

Septic systems are a problem, but cattle are the primary source of bacteria in the Kettle and Upper St. Croix watersheds.

“Livestock animals were by far the biggest bacteria producer (85% to 99%) in the 10 impaired reach watersheds that have at least one MPCA registered feedlot,” the report says.

There are 77 feedlots, home to about 26,000 animals, mostly cattle, in the two watersheds.

Feedlots can cause elevated bacteria levels in streams either from cattle defecating in the waterway or tributaries, or from runoff from manure spreading on farm fields. The report points to both issues in this region..

“There is a significant amount of late winter solid manure application (before the ground thaws),” the MPCA says. “During this time, the manure can be a source of nutrients and pathogens in rivers and streams, especially during precipitation events.”

Both issues are largely fixable.

Several measures have already been taken to keep cattle out of streams — by installing water sources elsewhere and fencing off most stream accesses for the animals. Nutrient management plans and other practices can help farmers prevent the manure they spread on fields from reaching waters downstream. This can be accomplished by constructing more manure storage to allow waste to be stored until appropriate times for spreading.

A balanced diet

Kettle River (Michael Hicks/Flickr)

The Kettle and Upper St. Croix watersheds contain a combined 126 lakes of ten acres or larger. Researchers studied 31 of those lakes, and found that 18 meet water quality standards.

The lakes that are impaired are primarily affected by high levels of nutrients, like phosphorus. These chemicals can come from septic systems and feedlots, as well as cropland and other sources. High levels of such nutrients can feed algae that affect swimming, boating, fishing, and aquatic life.

The MPCA and partners found lakes with excess nutrients in both watersheds, though a relatively small number compared to other watersheds in the state. Most of the lakes and streams in the region are nearly pristine.

Three lakes in the watershed that are prized for recreation suffer from excess nutrients: Pine, Big Pine, and Grindstone.

Several of the impaired lakes seem to be suffering from historical contamination. Once nutrients make it into a lake, they can be essentially stuck in a cycle of feeding algae and then decaying in the bottom sediments. While nutrient levels may slowly decline over decades, treating the lake with special compounds to trap the nutrients in the sediment is sometimes necessary — but costly.

Protecting waters that aren’t impaired yet is far easier than trying to remediate them. Removing sources of nutrients — from erosion of gullies and stream banks, and capturing runoff from crop fields — can help keep the waters clean.

While the new reports focus on impaired waters and how to fix them, ensuring the healthy ones stay that way is another priority.

Goals and plans

The Kettle River winds through Saint Croix State Park, Minnesota, in winter. As seen during a sunset on the Kettle River Highbanks Trail. (Tony Webster/Wikimedia)

There are ways to help those lakes and rivers affected by either nutrients or bacteria. Knowing which ones are in trouble is the first step.

The studies currently available for public review are intended to identify problems and propose solutions. It’s part of a process required by the federal Clean Water Act. It includes a forecast of how conversation actions will help improve the health of lakes and streams over the next two decades.

Scientists expect pollution levels to decline by 2-3 percent each year until 2040, when most waters should begin to meet standards. It will take work, though fortunately much of the watershed remains healthy.

With a solid benchmark of current conditions in waters throughout the region, it will also be easier to notice new sources of pollution.

Citizen volunteers will continue to be an important part of the monitoring effort, conducting regular water quality monitoring on lakes and streams throughout the watershed, providing data that scientists simply can’t visit often enough to collect.

Right now, volunteers monitor water quality at 22 stream sites and on 43 lakes. The MPCA says there is a lot of room to expand those opportunities, and pledges to work with local governments to recruit more volunteers.


The draft reports are available on the MPCA’s Kettle River or Upper St. Croix River watershed web pages.

Written comments must include a statement of the respondent’s interest in the report, and the action you are requesting, including specific changes to sections of the draft report and the reasons for making those changes.

Submit comments to or request information from Karen Evens at, 218-302-6644, or 1-800-657-3864, MPCA, 525 Lake Ave., Suite 400, Duluth, MN, 55802 by 4:30 p.m. on Wednesday, February 10.

After receiving comments and revising the plan, it will be sent to the federal Environmental Protection Agency for approval.

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One response to “Healthy headwaters: Upper St. Croix tributaries are mostly pristine — and need protection”

  1. Dana L Jackson Avatar
    Dana L Jackson

    The following from the story above is NOT an answer to preventing manure contamination of streams:
    “Nutrient management plans and other practices can help farmers prevent the manure they spread on fields from reaching waters downstream. This can be accomplished by constructing more manure storage to allow waste to be stored until appropriate times for spreading.”
    Instead of more manure storage, fewer confined animals that require manure storage should be a goal. Incentives for managed rotational grazing should remove the need for manure storage.