Looking back at 2025 Developments in Wisconsin Water Law and Policy

2025 was a momentous year for water law and policy issues, both in Wisconsin and nationally. In this post, I focus mainly on some Wisconsin-specific developments and then summarize a few national-level issues.

Water use at data centers. The past year saw the emergence of widespread public concern over the environmental impacts of data centers—facilities that store and share vast amounts of data for the internet, artificial intelligence, cloud storage, and related applications and services, resulting in community opposition in some places. By most counts, Wisconsin is already home to more than 40 data centers, with several more in development. Data centers have become controversial because of their effects on the environment; perhaps most prominently, some use significant amounts of water for cooling their sensitive equipment (reportedly millions of gallons per day, in extreme cases). Other data centers have “closed loop” recycled water systems that use much less water but require increased electricity to operate. Of course, water and energy are closely connected – water is required to produce energy, and energy is required to treat and deliver clean water. This means that even those data centers that use recycled water systems have a sizable water footprint, considering the water used at the energy generating facility. Complicating the matter further, some data center developers have required host municipalities to sign nondisclosure agreements that purport to treat water use as a trade secret. Several proposed sites are facing backlash from surrounding communities.

PFAS rulemakings. The Wisconsin Department of Natural Resources (WDNR) is engaged in several rulemaking efforts related to per- and polyfluoroalkyl substances (PFAS). The term “PFAS” encompasses a broad range of chemical compounds, not a single substance.  Since the 1950s, PFAS have been manufactured around the world and widely used in a broad array of products including food packaging, cosmetics, non-stick cookware, and firefighting foam.  Prized for their durability and propensity to repel both oil and water, PFAS do not break down easily in the environment and have been tied to serious risks to human health. PFAS are commonly called “forever chemicals” because of the lack of degradation pathways. 

WDNR’s ongoing regulatory efforts include setting limits for PFAS in groundwater (updates to Wisconsin Administrative Code Chapter NR 140), management of firefighting foam containing PFAS (updates to Chapter NR 159), and bringing Wisconsin drinking water rules for PFAS in line with federal standards (updates to Chapter NR 809). More information about these efforts can be found here on WDNR’s website.

Spills Law. The Wisconsin Supreme Court sided with the WDNR in a dispute over the extent of the agency’s authority to require responsible parties to clean up releases of PFAS and other emerging contaminants under the state’s “Spills Law,” Wis. Stat. s. 292.11. At its core, the Spills Law requires a person who causes the discharge of a “hazardous substance” (or who possesses or controls a hazardous substance that has been discharged) to notify WDNR of the spill and then to “take the actions necessary to restore the environment”—a potentially time-consuming and expensive process.

The central question in the case decided in June, Wisconsin Manufacturers and Commerce, Inc. et al. v. Wisconsin Natural Resources Board, et al., arose over whether WDNR could continue its historical practice of identifying “hazardous substances” on a case-by-case basis, or whether it had to engage in administrative rulemaking to create a list identifying which substances it considered hazardous, and at what quantities or concentrations in the environment. The rulemaking process is lengthy and often controversial, so a decision against DNR would have posed substantial challenges for it, potentially eliminating its ability to respond in real time to spills of emerging contaminants. On the other hand, a list of hazardous substances would provide predictability and certainty to parties responsible for cleanups under the Spills Law.

The supreme court held in DNR’s favor that the agency could continue its practice of determining whether a release involved a “hazardous substance” based on the individual circumstances of each case. The court held that the statute’s “broad and open-ended” definition of “hazardous substance” is cabined by the requirement that the substance significantly increase mortality or contribute to serious illness in humans, or that it may pose a substantial hazard to human health or the environment.

In considering how the Spills Law works, context is important, the court observed: “a gallon of milk spilled into Lake Michigan may not ‘pose a substantial present or potential hazard to human health or the environment,’ but a 500-gallon tank of beer or milk discharged into a trout stream might well pose [such a hazard] to the stream’s fish and environment.” Thus, the court thought it was critical for DNR to retain some flexibility in interpreting the statute.

Climate litigation and Wisconsin water resources. From constitutional claims that seek to reform the implementation of energy law in the state, to litigation over the federal government’s efforts to claw back funding for the development of renewable energy resources, Wisconsin has become increasingly involved with legal battles over the climate. Interestingly, one of the cases prominently invokes a constitutional doctrine connected to the state’s water resources – the public trust doctrine. Read more about these developments in one of my previous blog posts.

Aftermath of Evers v. Marklein II. This summer the Wisconsin Supreme Court issued its opinion in Evers v. Marklein II, striking down the authority to pause, object to, or suspend administrative rules held by the powerful legislative Joint Committee for Review of Administrative Rules (JCRAR). The basis for the ruling was a rather technical matter: the court held that JCRAR’s authority to block, suspend, and object to administrative rules was tantamount to legislative action, and therefore failed the constitutional requirements of bicameralism (a bill must pass both houses) and presentment (the bill must be provided to the governor for signature). Technical grounds notwithstanding, Evers v. Marklein II appeared to significantly reduce the legislature’s power to check agency action, although it also touched off a new round of political squabbling ultimately leading to Governor Evers suing the legislature all over again.

Ten years of Wisconsin water use data. The WDNR released its annual Report on Water Withdrawals, which gives an overview of the past decade of water withdrawals throughout Wisconsin. In an era of uncertainty over the reliability of information, the report provides very valuable data about water use in Wisconsin.

The DNR summarized the main takeaways from its report as follows:

  • “The largest water withdrawals were for power production, municipal water supply and crop irrigation.
  • In 2024, Wisconsin cities, agricultural operations, businesses, industry and power generation facilities withdrew almost 1.7 trillion gallons from groundwater and surface water sources – the equivalent of just over 1% of the volume of Lake Michigan.
  • Power production was the largest water use category at 73% of the total water in 2024, with municipal supply following at 11%.”

Developments at the federal level have been largely driven by the second Trump administration. Some of these were expected, such as the administration’s proposed rule to narrow the regulatory definition of “waters of the United States” (WOTUS) to better conform with the Supreme Court’s 2023 decision in Sackett v. EPA. The issue is important because it dictates whether a federal permit is required to fill wetlands. Obtaining the permit can be a time consuming and expensive process – but also one that protects a critical environmental resource. Sackett narrowed the class of qualifying waters to traditional waters that are navigable in fact, such as rivers and lakes, and all other waters that have a continuous surface connection to waters in the first category, such that the boundary between them is indistinguishable.

Other developments were mildly surprising, such as the administration’s apparent decision to defend the Biden administration’s lead and copper rule, which had been challenged by water utilities as unreasonable given its establishment of a ten-year deadline for public water systems to replace all lead pipes within their jurisdiction.

Still other developments occurred in the judicial branch, perhaps the most important being the Supreme Court’s opinion in San Francisco v. Environmental Protection Agency. The Clean Water Act generally prohibits the discharge of a pollutant to surface waters, unless the discharger holds a permit issued under the Act. In San Francisco, the U.S. Supreme Court held that EPA lacked the authority to issue what the Court termed “end-result” conditions in those wastewater discharge permits. Those conditions are sometimes known as “narrative” limitations that take the form of a water quality goal when numeric standards are too difficult to quantify. For example, such a condition may prohibit a permittee from “creating pollution, contamination, or nuisance,” or from “causing or contributing to the violation of water quality standards.” The City argued that these standards were too vague to enable compliance. The Court held that “end result” provisions exceeded EPA’s authority because they condition a single discharger’s compliance on whether the receiving waters meet applicable standards. The holding is likely to change permit drafting processes and enforcement actions nationally.  Permits will have to be more detailed and provide more clarity on specific (numeric) effluent standards necessary to avoid impacts to receiving water quality.

Continue ReadingLooking back at 2025 Developments in Wisconsin Water Law and Policy

Climate litigation comes to Wisconsin

Wisconsin’s climate is warming. Despite its characterization in some quarters as a “climate haven” and destination for people migrating away from the worst impacts of climate change, the state is not immune to some of those same consequences. Even setting aside the significantly warming temperature here, the effects already include more frequent, intense precipitation events, increased flood risk, and decreased opportunities for winter recreation. Wisconsinites living in the southeastern part of the state will long remember the August 9-10, 2025 rainfall event that hammered some areas with over 14 inches of rain in under 24 hours, leading to widespread flooding. No doubt that was a “1,000-year storm” by reference to past experience. But when it comes to climate, the past is no longer a good guide to the future; indeed, some parts of the state have recently experienced multiple “500-year storms” or “500-year floods” within only a few years of time.

Perhaps it is no coincidence, then, that as the state increasingly feels the effects of climate change, climate law cases are similarly piling up here. From constitutional claims that seek to reform the implementation of energy law in the state, to litigation over the federal government’s efforts to claw back funding for the development of renewable energy resources, Wisconsin has become increasingly involved with legal battles over the climate. Interestingly, one of the cases prominently invokes a constitutional doctrine connected to the state’s water resources.

Dunn v. Public Service Commission. In August 2025, fifteen Wisconsin youth filed suit in the Circuit Court for Dane County alleging that certain Wisconsin statutes “create and perpetuate a fossil fuel-dominated electricity sector,” resulting in climate change-driven injuries to plaintiffs caused by air pollution, extreme weather events, and degradation of Wisconsin’s public trust (water) resources. Plaintiffs assert this amounts to a violation of the Wisconsin Constitution’s guarantees of life, liberty, and “a stable climate system.” That last phrase doesn’t appear in the constitution, but plaintiffs argue that it is inherent in the enumerated rights of life, liberty, and the pursuit of happiness. The case is a cousin of similar youth-led suits filed across the country, including a recent notable success in the Supreme Court of Montana.

The claims involve the work of the Wisconsin Public Service Commission (PSC), which is charged with approving the construction of new facilities that will generate electricity in the state. The Dunn plaintiffs allege that one Wisconsin statute unlawfully prohibits the PSC from considering the air pollution these proposed facilities will emit, leading to an artificial bias in favor of electricity generation from fossil fuels rather than renewable resources. A second set of challenged laws, plaintiffs allege, creates an artificial and unlawful ceiling on the amount of renewable energy generation the PSC may require energy providers to supply.

Alternatively – and particularly thought-provoking for those interested in Wisconsin water law – the plaintiffs allege that the same statutes also violate the Wisconsin public trust doctrine by depriving the plaintiffs of “the [constitutionally guaranteed] right to access, enjoy, and use public trust waters.” Over the years I have written several times in this space about the Wisconsin public trust doctrine, including its recent re-solidification after a period of erosion. In short, Wisconsin courts have interpreted Article IX, Section 1 of the state’s constitution to mean that Wisconsin holds its navigable waters in trust for its people, but the courts have had some difficulty operationalizing exactly what that duty requires in terms of day-to-day management of Wisconsin waters. The plaintiffs in Dunn argue that climate-driven damage to Wisconsin water resources enabled by the PSC’s (statutorily mandated) decisions related to electricity generation equates to a breach of the state’s constitutional public trust obligations. If a Wisconsin court accepts that framing, Dunn could become a nationally significant point of climate law evolution.

While Dunn targets the legal architecture of the state’s energy system, another pending case is focused on funding for the development of renewable energy generation in Wisconsin.

Maryland Clean Energy Center, et al. v. United States. Wisconsin (through the Wisconsin Economic Development Corporation, a public-private entity created in 2011 to replace the former Department of Commerce) has joined other states and organizations suing over EPA’s decision to terminate the “Solar for All” program, which is aimed at improving access to solar energy infrastructure in lower-income and disadvantaged communities. The program was slated to fund about $7 billion in solar projects; Wisconsin would have received over $60 million of that amount. The controversy involves the recent reconciliation law passed in July, which Wisconsin and the other plaintiffs argue only rescinds unobligated balances of the funding, and is not a retroactive repeal of funding already issued under the program. In a related case, EPA has called such claims “hopeless,” arguing that Congress provided reasonable grounds for getting rid of the entire program and its associated funding.

Enbridge Line 5. The Wisconsin-based dispute over the rerouting of Enbridge Line 5, an oil and gas pipeline that crosses northern Wisconsin on its way from Canada to Michigan, is another fossil fuel-related case with national relevance. Litigation over the pipeline, and the fossil fuel resources it transports, is ongoing in several different jurisdictions. In our state, the Bad River Band of Lake Superior Chippewa has challenged the Wisconsin Department of Natural Resources’ issuance of permits approving a 41-mile new section of the pipeline, arguing that the DNR’s approval fails to comply with Wisconsin’s environmental laws and will damage wetlands and water resources, thereby threatening the Band’s way of life. The case is currently pending before a Wisconsin administrative law judge.

Though Wisconsin isn’t the first state that comes to mind in a conversation about climate risk, the outcome of these cases will be very significant to the development of climate law both within and outside the state.

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New Controversies in Wisconsin Administrative Law

Administrative law is enjoying a moment in the sun. Take, for example, the attention recently paid to the subject by the United States Supreme Court, which in a series of opinions (Loper Bright, Corner Post, andJarkesy) marked out a new path forward with respect to important aspects of federal administrative law. This post concerns noteworthy developments in the same field in Wisconsin. At both the federal and state levels, it has become clear that modern administrative law cases often involve disputes over very significant and substantive regulatory power, even when cloaked in what may seem to be procedural minutiae.

in recent years. I explored the topic in a series of writings, beginning in September 2017 with a post titled “The Quiet Revolution in Wisconsin Administrative Law.” My purpose was to point out what I perceived as a significant makeover in longstanding principles of administrative law in the state, shifting power away from agencies and toward courts and the legislature. Eight years have passed since then, and while the ground has certainly shifted, the fundamental questions remain the same, relating to the uneasy balance of power between Wisconsin agencies, the Wisconsin state legislature, and Wisconsin courts.

The Wisconsin Supreme Court has twice acted to counter the trends I noted in the original post, restoring some of the discretion Wisconsin agencies historically enjoyed. First, as I described in a 2021 post, the court decided two cases (both captioned Clean Wisconsin v. Wisconsin Department of Natural Resources (2021 WI 71 and 2021 WI 72wi)) to address the scope of Wis. Stat. § 227.10(2m). That statute provides that no agency may implement any “standard,” “requirement,” or permit condition unless the condition has been “explicitly required or explicitly permitted’ by statute or by rule. The Clean Wisconsin cases turned on a question of statutory interpretation: whether “explicit” means “specific,” in other words, whether under § 227.10(2m) the agency’s contested authority must be spelled out via “literal enumeration or verbatim mention” of the conditions in a statute or rule, or whether the authority must simply be “expressly conferred and clear.”

The court concluded that even when no statute or rule spells out verbatim the agency’s authority to impose certain disputed permit conditions, an agency “may rely upon a grant of authority that is explicit but broad when undertaking agency action.” Such broad grants of authority, the court found, comply with the requirements of § 227.10(2m). For example, statutes conferring on the Wisconsin Department of Natural Resources (WDNR) “general supervision and control over the waters of the state” and all “necessary powers” to protect the waters of the state, provided sufficiently “explicit” authority for WDNR to impose specific conditions related to groundwater monitoring on a permitted well.

Most recently, this summer the Wisconsin Supreme Court issued its opinion in Evers v. Marklein II, striking down the authority to pause, object to, or suspend administrative rules held by the powerful legislative Joint Committee for Review of Administrative Rules (JCRAR). This was another power shift that I discussed in my 2017 post. The basis for the court’s new ruling was a rather technical matter: JCRAR’s authority to block, suspend, and object to administrative rules was tantamount to legislative action, and therefore failed the constitutional requirements of bicameralism (a bill must pass both houses) and presentment (the bill must be provided to the governor for signature). Technical grounds notwithstanding, Evers v. Marklein II appeared to significantly reduce the legislature’s power to check agency action.

But rather than putting things to rest, the ruling touched off a new round of political maneuvering. First, Democratic Governor Tony Evers sought to finalize a set of new administrative rules without first submitting them to the JCRAR, citing the court’s opinion. Republican leaders responded with a plan to order the Legislative Reference Bureau not to publish any rules prior to review by legislative standing committees, arguing that the court’s opinion removing some authority from the JCRAR did not eliminate review of administrative rules by standing committees. The LRB director agreed, telling a media outlet that “If [the Joint Committee on Legislative Organization] so directs, the LRB will not finalize or publish any proposed administrative rules that have not completed standing committee review.” Many of the rules – which concern various aspects of important state policies – remain in limbo for now.

While the debate over the authority of Wisconsin administrative agencies currently pits the Republican legislature against the Democratic executive, there is always the possibility that those positions could be reversed in the future – just as has happened at the federal level, with a Republican-led EPA now seeking to impose the most ambitious deregulatory agenda in history. For that reason alone, this delicate balance of authority should be examined on more than partisan political terms.

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