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Mississippi River conservation groups are among a broad coalition urging the federal government to take action against nitrate contamination in drinking water, which they say has reached “crisis levels” and is a public health emergency.

Nitrate, which forms when nitrogen-rich sources combine with oxygen, has long been found in the country’s surface waters and groundwater, where it can end up in people’s drinking water. Consuming water with elevated levels of nitrate is linked to birth defects, thyroid problems and some cancers.

Agricultural fertilizer and manure are the most common sources of nitrogen to groundwater, with septic systems and lawn fertilizers also contributing. An April analysis from the Environmental Working Group found that about 18% of the U.S. population from 2021 to 2023 used drinking water from community systems with 3 milligrams per liter (mg/L) or more of nitrate, the threshold at which the Environmental Protection Agency says indicates contamination.

Advocates say nitrate contamination has struggled to capture public attention but is costly and hazardous to those it affects. 

A May 5 letter to the Department of Health and Human Services and the EPA was signed by 80-plus groups, about a third of which are located in or focused on the Mississippi River basin. It calls on the agencies to “immediately identify and eliminate sources of nitrate pollution in drinking water and provide funds to communities to reduce nitrate to safe levels.”

The letter cites a recent report from the Iowa Environmental Council and the Harkin Institute at Drake University in Des Moines that found high nitrate levels in drinking water, as well as the presence of pesticides and forever chemicals, are linked to rising cancer rates in Iowa. Intensive farming across the state, including corn, soy and hogs, is the dominant source of nitrate pollution, the report notes.

“We understand these are long-term problems,” said Tyler Lobdell, senior attorney at Food & Water Watch, which spearheaded the letter. “The longer we wait to address root causes, the more difficult, and more expensive (it is), and the more harm is caused in the long run.”

The Department of Health and Human Services did not respond to a request for comment on the letter. A spokesperson for the EPA said it is beginning the next round of review of national drinking water regulations, last published in 2024.

Too much nitrogen taints drinking water, hurts river ecosystem

Nitrate contamination is a widespread problem across the country, especially in the Corn Belt, but actions to address it have been slow-going.

Groups in multiple states, including Wisconsin, Minnesota and Iowa, have previously petitioned the EPA to take emergency action on nitrate problems in specific regions. Lobdell said the agency has either ignored or given an insufficient response to those petitions, dating back several years and multiple presidential administrations.

Under former President Joe Biden, the EPA restarted an assessment — which had been suspended during the first Trump administration — of the impacts of nitrate on human health. Environmental advocates had hoped that it could lead to an adjustment of the national standard for nitrate in drinking water, which currently sits at 10 mg/L, because some research shows impacts to human health below that level. Little progress has been made on the assessment.

Beyond human health impacts, too much nitrogen in surface water can drive excessive algae growth, causing harm to fish and other aquatic life. It’s one culprit, in addition to phosphorus, in the creation of the Gulf of Mexico’s “dead zone,” an area of low oxygen that spans thousands of square miles from the mouth of the Mississippi River.

Kelly McGinnis, executive director of the environmental advocacy organization One Mississippi, a signatory on the letter, said that humans aren’t separate from the environment and that addressing nitrate contamination would have positive impacts on both.

She said she hopes the letter catches the attention of Health and Human Services Secretary Robert F. Kennedy Jr., who has pledged to “Make America Healthy Again” and has shown interest in reducing toxins in people’s diets.

“We felt the urgency right now to take advantage of the new research (from Iowa) to say, ‘Hey, this is something you guys need to be addressing,'” McGinnis said.

The spokesperson for the EPA said the agency is “committed to Making America Healthy Again by taking real, tangible steps to evaluate risks of nitrates in drinking water while following the law and gold standard science.”

This story is a product of the Mississippi River Basin Ag & Water Desk, an independent reporting network based at the University of Missouriin partnership with Report for America, with major funding from the Walton Family Foundation.

Wisconsin Watch is a member of the Ag & Water Desk network. Sign up for our newsletters to get our news straight to your inbox.

Mississippi River groups tell feds to act on nitrate contamination is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.

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An attorney read from a laptop propped atop a snowplow.

To his left was a Caterpillar street grader, and to his right, a dusty workbench. A disheveled American flag hung next to a red toolbox in the center of the impromptu stage.

Dozens of southwest Wisconsin residents recently forsook part of the local high school’s track-and-field meet so they could cast their votes inside the town of Cassville’s garage. The attorney had been retained by the town’s elected leaders to read the soon-to-be-newest regulation.

The unanimous outcome — 44 ballots in favor of banning data centers, none against — reflected a hostile backlash to unwelcome big tech incursions into rural spaces.

Residents instructed their town board to put a stop to the billion-dollar proposal by an anonymous developer after learning their community was on the short list.

Even promises of 50 jobs and more than $5.5 million in annual property tax revenue weren’t enough to make up for the loss of about 500 acres of Wisconsin’s Driftless area.

The pastoral landscape — known for rolling bluffs that straddle the locks and dams of the nation’s upper Mississippi River — possesses a bountiful aquifer, a temperate climate and few land regulations.

The latest move against data centers

Cassville’s ordinance is the latest move by a Midwestern community seeking to protect the qualities that make life so appealing to people — and data centers. 

Pushback over the power-hungry facilities that make the cloud run are occurring across the country, as companies expand in states like Mississippi and Tennessee.

Residents in Port Washington, Wisconsin, were the first in the nation to pass a referendum that would prevent their city from offering generous tax incentives without first obtaining voter approval.

Wisconsin lawmakers — some of whom previously supported a state sales tax exemption for new data centers — sponsored bills that would prevent developers from using confidential nondisclosure agreements when prospecting for new sites.

And in Clayton County, Iowa, directly across the river from Cassville, officials are considering zoning, setback and size restrictions.

Cassville residents fear data centers will devalue their properties, contaminate their wells and increase their electric bills.

“This is the Driftless area for Christ’s sakes,” said John Hawn, who retired to the area several years ago. “I suppose they didn’t expect any problems coming into a small town.”

‘There’s no information’

The Cassville project has been shrouded in secrecy. That includes the proposed location and what company will use it, leaving residents to fill in the vacuum with a frenzy of social media engagement.

“I don’t know really what to think about it because there’s no information,” town Supervisor Scott Riedl said. 

Ron Brisbois, executive director of the Grant County Economic Development Corp., has met with a developer but to date declined to identify the company that is scouting for locations so as not to jeopardize the project.

In an interview after Cassville’s vote, he said the town’s appeal is its proximity to electricity, specifically the high-voltage Cardinal-Hickory Creek transmission line that entered service in September 2024.

Brisbois estimated the data center would require 400 to 500 megawatts of power — a lot, even by the new transmission line’s standards.

But the town’s attorney, Eric Hagen, said if Cassville can make it inconvenient, the data center developer may look elsewhere. The company also is considering sites in Indiana and North Dakota.

“My read of the situation right now: They’re looking for the lowest-hanging fruit with the least amount of regulations,” Hagen said.

Cassville’s new ordinance prohibits data centers in the town for up to two years and prevents land use changes, such as constructing a residence on a farm field, without the town board’s approval. And the county cannot preempt local zoning authority in the town’s case, Hagen said.

“We can beat them to the punch.”

Data centers raise ire

Days after the town’s vote, Brisbois fielded questions from a concerned public at J&J’s Sandbar, a Cassville restaurant, over chicken and ham, mashed potatoes with gravy and macaroni salad.

He wonders whether the objections reflect data centers’ tarnished image more than concerns over actual water and power use. If a battery or farm equipment manufacturer were to move in and consume more of each, would residents even notice?

Brisbois said the developer has remained quiet for the past month, which he attributes to the lack of local tax incentives for the project rather than community unease.

“I’m looking forward to a bit quieter days,” he said, “where all I have to worry about with townships is housing and maybe an ag or a farm expansion.”

In rural Wisconsin, a town rejects a plan to build a massive data center is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.

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April 22, 1970, was no ordinary day in the bustling city of St. Louis. On this first Earth Day, streets filled with rallies, and lecture halls were packed with attendees. Most famously, rows of students marched through the streets wearing gas masks, protesting air pollution.

Around that time, John E. Franz was brewing up something dark in the depths of Monsanto’s St. Louis lab: glyphosate, an herbicide since linked to widespread environmental harm, cancer concerns and more than 100,000 lawsuits. 

While other countries have regulated or limited glyphosate production, the U.S. has largely ignored the problem. In February, President Donald Trump issued Executive Order 14387 to promote the production of glyphosate and security for its producers.

The U.S. is increasingly dependent on glyphosate, and its overuse is becoming a serious concern. Amid the many environmental issues competing for attention, glyphosate deserves a prominent place this Earth Day, especially in Wisconsin.

Why Wisconsin? Glyphosate levels in groundwater aren’t being consistently monitored in the state’s highest-risk areas — its CAFO counties.

From fields to faucets 

Wisconsin farmers apply millions of pounds of glyphosate each year, primarily to fields growing soybeans and corn — the state’s two biggest crops. Those crops are used to feed animals at Wisconsin’s 293 concentrated animal feeding operations, or CAFOs. 

After animals eat glyphosate-treated crops, the chemical can reemerge in their manure. This is a problem, considering that mismanagement of CAFO waste frequently leads to groundwater contamination. 

Seems like something that should be setting off red flags, right?

Monitoring falls short in Wisconsin

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) oversees groundwater and surface water testing for agrichemicals. The agency monitors pesticides and agricultural runoff through a private well sampling program, a field-edge monitoring program and random well sampling conducted every five to 10 years.

However effective these programs may appear, a closer look at where Wisconsin’s CAFOs are located compared with where monitoring occurs reveals a stark mismatch.

The three counties with the most CAFOs — Manitowoc (25), Brown (22), Kewaunee (19) — are all located in the Northeast Lakeshore region, where none of DATCP’s 22 field-edge monitoring wells are located, according to a 2023 report, the most recent available. The state’s monitoring system misses areas at highest risk for aquifer contamination.

Unfortunately it gets worse. DATCP’s Targeted Sampling Program also does not cover the entire Northeast Lakeshore Watershed, and these sampling panels do not test for glyphosate or its byproducts, the agency’s most recent program report shows.

The solution? Advocacy

Glyphosate usage has increased 15-fold since the 1990s. It will continue to go unchecked if more research and monitoring aren’t conducted to track where this chemical ends up.

What can citizens do? Write, speak and act.

1. Monitor the DNR’s hearing and meetings calendar for groundwater-related meetings you can attend.
   
2. If you’re a private landowner with a well, write to DATCP and volunteer to have your well sampled.
   
3. Universities such as University of Wisconsin-Oshkosh and UW-Green Bay also play a role. DATCP already partners with both on research. Contact leaders of their water-related programs.

Why glyphosate still matters

To be sure, glyphosate is not the only problematic agrichemical. But it is by far the most widely used herbicide in U.S. agriculture, and its scale alone warrants closer monitoring of its spread in aquifers.

Still not convinced? Consider the many other contaminants that can leach into groundwater from CAFO manure — including other agrichemicals, pharmaceuticals, heavy metals and bacteria. Glyphosate is just one of many reasons stronger groundwater monitoring is needed in this region.

We’re not asking for much.

Glyphosate well testing is relatively inexpensive and should not strain government resources. Progress will depend on public pressure: Concerned citizens must keep pushing until stronger monitoring is in place across all at-risk areas of this beautiful state we call home.

Allison Gilmeister is a graduate student at Yale University studying religion and ecology. She grew up in Appleton. 

Opinion: In Wisconsin’s CAFO counties, glyphosate monitoring gaps threaten groundwater is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.

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Beavers have been in the news these past few months in a variety of ways. The latest Pixar movie, “Hoppers,” features an animal lover who “seizes an opportunity to use a new technology to ‘hop’ her consciousness into a lifelike robotic beaver and communicate directly with animals.”

The filmmakers worked with a University of Minnesota ecohydrologist, Dr. Emily Fairfax, as a science expert, even naming a key character for her (Dr. Sam — for Samantha Emily Fairfax), per Minnesota Public Radio. She visited the studio several times and led a research trip to Colorado to help the team learn more about beavers and their habitat.

In that MPR story, Fairfax said Pixar did a good job showing how beavers can improve ecosystems with their dams.

“When you lose that beaver, you also lose the homes for the other animals, and I think that’s a message that not everybody really understands,” she told MPR. “If you trap a beaver out, if you remove its dam, you will take away a lot more than just the beaver from that ecosystem, whether you meant to or not.”

She also spoke to the question of beavers as a nuisance or pest, a topic I’ve been reporting on for a few years now and interviewed her about for a recent story.

Researchers have identified Wisconsin as being among the top 10 states for biodiversity loss, largely due to climate change and animal overexploitation. But a vocal minority serving on a beaver advisory committee that is drafting recommendations for the state’s Department of Natural Resources believes it’s time for a change: Beavers should cease to be framed as a nuisance species and instead as an ecosystem engineer that creates wetlands. That can help reduce some of the worst effects of climate change: droughts, floods and fire.

The U.S. Department of Agriculture’s wildlife services program lethally removes beavers in Wisconsin and other states throughout the Midwest. In Wisconsin, wildlife services staff trapped about 2,200 beavers in 2025 and removed more than 800 dams.

The majority of beaver committee members — mostly composed of state and federal employees and interest groups — support the status quo. Those who do not have criticized the committee as stacking the deck against people who would advocate for substantive changes in policy. This makes, they say, the outcome a seemingly foregone conclusion. Some committee members have said a survey released to gauge the public’s tolerance of the critters frames beavers as pests and fails to mention the effectiveness of coexistence methods.

As Wisconsin Watch previously reported, the state has an arduous and often expensive permitting process to install flow control devices that can lower water levels in beaver ponds or prevent the blockage of culverts. That can usher landowners toward lethal solutions, the use of which Wisconsin law liberally allows.

People may hunt or trap beavers and remove their dams on their property without obtaining a license or reporting their catch. In fact, there are risks to ignoring one’s beavers.

People who own or lease beaver-occupied land and don’t allow their neighbors to remove them are liable for damages. Additionally, if a beaver dam causes damage to a neighboring property, the injured party may enter the property where the dam lies and remove it without being charged with trespassing.

Committee members petitioned to have Fairfax address the group. She stressed beavers’ role as a “keystone” species, on whom many plants and animals depend.

“It is harder to coexist,” she said. “But in many cases, it is worth it.”

Pest or nuisance? The role of beavers in ‘Hoppers’ and the real world is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.

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A homeowner in Wauwatosa can do exactly what public messaging asks: take shorter showers, time irrigation thoughtfully, fix leaks and otherwise reduce water use. Then the quarterly bill arrives, and the cost barely moves. The homeowner might jump to a dangerous conclusion: that conservation is symbolic, not economic.

It’s an understandable reaction to misaligned incentives.

Utilities need stable revenue to maintain infrastructure that does not shrink with short-term changes in household use. At the same time, households need bills that make conservation visibly and promptly worthwhile. If both are true, the issue is not whether residents are wrong to feel frustrated, but whether rate design effectively translates public goals into household-level incentives.

This tension — between conservation messaging and what bills actually show — points to a broader public accountability issue for utilities across Wisconsin.

Wauwatosa is a useful case study because the city publishes its bill components clearly enough to reveal this trade-off.

What the Wauwatosa bill structure shows

As published by Wauwatosa’s water utility, a residential bill combines multiple components across water, sewer and storm water. For common 5/8-inch and 3/4-inch meters, the city page currently lists:

• A fixed quarterly water service charge: $20.00.
• A fixed public fire protection charge: $15.99.
• A fixed quarterly Milwaukee Metropolitan Sewerage District (regional sewer) connection charge: $16.41.
• A fixed quarterly storm water charge (per equivalent residential unit): $35.63.

Taken together, that amounts to $88.03 per quarter in fixed charges before any usage-based costs, local sanitary flows or temporary surcharges are added. For many households, that fixed baseline stands out because it does not change with daily behavior.

The Wauwatosa webpage notes another key detail: Residential sewer charges are based on average water use from the previous winter quarter. That approach can make engineering sense for irrigation-heavy months, but it also means residents who cut back now may not immediately see those savings reflected in their sewer charges.

When customers see both that delay and a large fixed baseline, the takeaway is simple: “My effort doesn’t matter.”

That is the policy risk.

Why this perception matters beyond one city

This pattern extends beyond Wauwatosa to utility systems statewide.

The Wisconsin Public Service Commission describes rate setting as a balancing problem among cost recovery, financial stability, affordability and system sustainability. EPA guidance similarly explains why many utilities use fixed-plus variable charges: Fixed charges support pipes, treatment assets and financing obligations that exist regardless of short-term household demand.

So yes, a large fixed component is not automatically evidence of bad intent. Often it reflects the cost profile of infrastructure.

But even well-designed systems can produce a weak conservation signal.

EPA water finance resources note that some pricing structures are better than others at encouraging conservation. If a city publicly asks for conservation while bill design makes savings hard to notice, policy and pricing are misaligned where customers experience them: on the bill.

The accountability test 

Can a typical resident estimate cost savings before taking action to reduce use?

If the answer is no, then the price signal is too opaque.

If customers must decode fixed charges, lagged sewer formulas and unclear unit rates to understand marginal savings, the bill functions more as a revenue tool than a behavior signal — preserving cash flow but weakening conservation and public trust.

Residents do not need a lecture about civic virtue. They need rate transparency and faster feedback.

What Wauwatosa could pilot 

This does not require a simplistic “slash fixed fees” response. It requires clearer design and better signal delivery.

• Publish a one-page “marginal savings” table for typical homes.The table should answer: “If I reduce use by 1, 3 or 5 CCF this quarter, what is the expected bill impact now and next quarter?” Include timing notes for winter-quarter sewer logic.
• Add bill lines for “behavior-sensitive charges” and “system-fixed charges.” Split the bill into two subtotals so the customer can see immediately which share was behavior-driven and which paid for infrastructure. 
• Introduce a conservation dividend. If systemwide demand drops below peak projections and defers capacity costs, return part of those savings as a visible credit in the next cycle. Make conservation legible.
• Run a transparent pilot on stronger conservation pricing bands. EPA and national guidance point to increasing-block rates as one way to strengthen conservation signals. Pilot carefully, publish distributional impacts and protect affordability with targeted credits.
• Publish a trust metric: “conservation-to-bill responsiveness.” Track how often conservation leads to measurable bill changes within one cycle. If responsiveness is weak, publish a redesign plan.

The larger policy point

When homeowners conclude, “the city designed this to extract money no matter what,” leaders should not dismiss it but treat it as a warning sign in the system.

Most residents are not accusing utilities of villainy. They are describing an incentive mismatch.

If Wisconsin cities want durable conservation, they need bill designs that preserve financial integrity and reward action quickly enough for residents to feel the loop. Otherwise, we train households to stop caring, then blame them for not conserving.

Water policy fails when the math is defensible on paper but illegible at the kitchen table.

Michael V. Haley is a Wisconsin freelance writer focused on accountability commentary about how public systems affect household outcomes. His work translates municipal policy, utility design and implementation choices into practical impacts for residents.

Opinion: How to fix water bills so conservation pays off is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.

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Microsoft data centers in Mount Pleasant in southeast Wisconsin are projected to use much more water annually than would fill four Olympic-size pools.

Water to operate the facilities, including for cooling, will be supplied by the city of Racine.

The first data center, described by Microsoft as “the world’s most powerful data center,” is expected to begin operation in 2026.

Racine projects that facility will use 2.81 million gallons of water (roughly four Olympic pools) in 2026.

But a second data center is also under construction and a 15-center expansion is planned.

Racine projects total water usage will be 8.44 million gallons annually (roughly 12 pools).

The projections don’t include water that will be needed to generate electricity to fuel the data centers.

The Lawrence Berkeley National Laboratory estimated in 2024 that 92.5% of the water U.S. data centers used was to generate electricity, 7.5% for cooling.

This fact brief is responsive to conversations such as this one.

Sources

• The Conversation: Data centers consume massive amounts of water – companies rarely tell the public exactly how much
• Microsoft: Made in Wisconsin: The world’s most powerful AI datacenter
• City of Racine Water Utility: Mount Pleasant data center water projections
• WPR: Mount Pleasant commission approves Microsoft’s plans for data center expansion
• Badger Institute: Claims of data center water use are laughably wrong
• WPR: Microsoft data centers will use up to 8.4M gallons of water each year, records show
• Midwest Environmental Advocates: Demanding Data Center Transparency – City of Racine
• Clean Wisconsin: Analysis: Offsite Water Use of Data Centers

Is a claim that a massive data center will use only 4 Olympic swimming pools of water per year accurate? is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.

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Members of an ad hoc Wisconsin Department of Natural Resources committee are urging wildlife regulators to work with a national expert as they finalize recommendations to guide state beaver management policy for the next decade.

Researchers and conservationists serving on the advisory body — which is largely composed of DNR staff and government and tribal representatives — hope that including additional scientific expertise, and even a potential computer-guided aerial beaver dam mapping survey, could assist regulators at a time when climate change is beginning to significantly alter Wisconsin weather patterns and pose widespread ecological risks.

“We’re taking our species out faster than they can recover, and when we are overexploiting our trout, when we’re overexploiting animals, plants, habitats, that’s going to make us lose these species faster,” said University of Minnesota ecohydrology professor Emily Fairfax, who has helped review and fact-check several beaver management plans and recently spoke to the committee. “I don’t think we have time to wait — full stop.”

A shift would transform long-standing beaver policy that frames the critters as a nuisance species.

The U.S. Department of Agriculture’s wildlife services program has removed beavers and their dams in Wisconsin since 1988 under contract with the state, along with local governments, railroad companies and Indigenous tribes.

At least five states across the Mississippi River basin and Great Lakes region contract with the federal wildlife services program for beaver removal, but Wisconsin stands out among states for the quantity of beavers and dams USDA employees clear, the millions of dollars Wisconsin has invested to do so and the state’s justification.

Current trout policy includes killing beavers 

USDA killed roughly 23,500 beavers across 42 states in 2024, about 2,700 of which were in Wisconsin, ranking the state among the top five in the nation.

In Wisconsin, the agency focuses on abating transportation hazards, such as flooded roadways. But, perhaps most controversially, about a third of sites where USDA traps beavers are coldwater streams.

Wisconsin currently prioritizes maintaining free-flowing conditions on the state’s prized coldwater streams, partly to appeal to its “customers” and their fishing preferences.

But the strategy has faced increasing scrutiny, even among anglers, who are divided over the issue. Some beaver advocates say the state agency charged with protecting and enhancing natural resources shouldn’t let commercial interests unduly guide its decisions. 

In 2025, the agency trapped and cleared dams in more than 1,550 miles of coldwater streams — roughly the driving distance from Milwaukee to Salt Lake City, Utah. The DNR uses proceeds from annual trout fishing stamp sales to finance the annual undertaking.

At least two other states, Minnesota and Michigan, have employed the USDA for trout stream clearing, but at a significantly reduced scale.

The DNR doesn’t know the impacts of these policies on Wisconsin’s beaver population, as it ceased conducting aerial surveys in 2014. Agency staff, instead, estimate beaver numbers and harvest impacts using trapper surveys and voluntary reporting of annual take. Staff believe the population remains stable statewide or is even growing.

Conservationists are calling on the DNR to systematically survey the state’s beaver population. Without obtaining a reliable count, they say, it’s impossible to devise a science-based management plan. Even if beaver removal continued on trout streams, critics say the state could better estimate the population by having trappers register their beaver take, as the DNR requires for turkey, deer, bobcat and bear harvests. 

Meanwhile, an expanding body of research is showcasing beavers’ ecosystem and economic benefits and the drawbacks of removal.

Beaver dams help limit flooding

When beavers remain on the landscape, they create wetlands, which mitigate climate change impacts like drought, wildfires and flooding. Problems thought to be endemic to the American West are now creeping eastward.

Thunderstorms wreaked havoc in southeastern Wisconsin last summer, bringing more than 14 inches of rain to some parts of Milwaukee within 24 hours on Aug. 9-10. Roughly 2,000 homes sustained major damage or were destroyed in the ensuing floods, and the county now faces more than $22 million in public infrastructure repairs after being twice denied federal disaster assistance.

Beaver dams can dissipate torrents of water when the sky opens — even to the city’s benefit.

Using computer models, University of Wisconsin-Milwaukee researchers estimated that the Milwaukee River watershed could accommodate enough beaver colonies to reduce flood water volumes by 14% to 48%.

Wisconsin beaver policy understudied

But scientists face decades of institutional consensus in Wisconsin that beavers degrade stream habitat and threaten wild coldwater fisheries.

DNR fish biologists say that beavers warm water temperatures and plug coldwater streams with silt. When unobstructed, the water bodies, which tend to contain few fish species, flow fast and hard.

“Past studies have identified some positive but mostly negative effects of beavers on trout, and my research builds upon this,” DNR fisheries scientist Matthew Mitro told the beaver management committee. “The option for lethal removal (of) beavers is an important tool that should remain available for resource managers.”

Yet critics charge DNR biologists with managing streams for the primary benefit of one species by trapping out another, justifying the practice using research that hasn’t undergone scientific peer review.

A 2011 academic review of beaver-related research conducted in the Great Lakes region, which predated Mitro’s recent research, found that 72% of claims concerning beavers’ negative impacts are speculative and not backed by data, while the same held true for 49% of positive claims. The negative claims included the idea that beaver dams warm stream temperatures and block trout passage.

DNR biologists often note that academic literature largely has been conducted in the western United States and can’t be directly transplanted to Wisconsin’s comparatively flat landscape.  

That is all the more reason to get off our haunches and wade into beaver ponds, Fairfax said.

“We have to follow that up by collecting our own data sets,” she said. “We have to publish them in peer-reviewed journals and get that scientific stamp of approval.”

Beaver trapping and natural predation are distinct from targeted eradication, Fairfax noted. The former can be sustainable, while stream-wide depopulation and dam removal can damage entire ecosystems. 

It’s also possible that stream clearing prevents beavers from moving to parts of Wisconsin where they are wanted or where they could thrive with fewer conflicts.

Federal government assesses Wisconsin’s beaver dealings 

The DNR beaver management plan’s update coincides with a new USDA environmental assessment of the potential impacts of its beaver and dam removal in Wisconsin.

A conservation organization founded by beaver management committee member Bob Boucher announced its intent to sue the federal agency to compel it to update its previous assessment, published more than a decade ago. Then Boucher threatened to sue the DNR after it wouldn’t release a draft of the new one, currently under review.

The 2013 assessment determined that USDA’s involvement in clearing streams and conflict areas did not significantly impact the beaver population. It estimated wildlife managers would only trap about 2,000 beavers annually, but the agency exceeded that figure within a few years.

The USDA recommends staying the course, using lethal and nonlethal methods. When analyzing alternatives, the agency concluded that other wildlife managers would continue trapping with or without federal involvement.

The USDA allocates some funding for the installation of flow control devices that can reduce the footprint of beaver ponds by lowering water levels. But nearly all beaver conflict sites the USDA handles in Wisconsin are managed through trapping. Levelers do have limited effectiveness in settings like high-flow streams or infrastructure-heavy floodplains. 

Wildlife managers say that they need flexibility because no two beaver sites are identical. 

“We’re not against beaver complexes,” DNR fisheries biologist Bradd Sims told committee members. “We’re not against ecosystem diversity, and I don’t know why people try to paint us that way. We’re an open-minded bureau that’s open to different management styles.”

Trout and beaver proponents do agree that climate change poses an existential threat to biodiversity. While the former group might view beavers as harmful to coldwater streams, the latter see their potential as a partner in creating resilient landscapes that accommodate not only fish, but also frogs, turtles, bugs, bats, birds and humans.

The committee’s next meeting is March 18 in Rothschild, Wisconsin. Ultimately, DNR staff will rewrite the current plan, release a draft for public comment and discussion at open houses, and present a revised document to the state’s natural resources board for ratification.

This story was produced in partnership with the Mississippi River Basin Ag & Water Desk, an editorially independent reporting network, of which Wisconsin Watch is a member. Sign up for Wisconsin Watch’s newsletters to get our news straight to your inbox.

Pest or climate ally? DNR weighs new beaver management plan under mounting scrutiny is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.