The long-standing struggle to define the scope of the federal Clean Water Act (CWA) has entered a critical new phase. On September 4, the U.S. Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (the Corps) issued a supplemental proposal aimed at clarifying the jurisdictional status of the nation’s wetlands and streams. This move follows a tumultuous period of regulatory flux triggered by the Supreme Court’s landmark 2023 decision in Sackett v. EPA, which fundamentally reshaped the legal landscape for construction, agriculture, and infrastructure development.
For over four decades, the definition of "waters of the United States" (WOTUS) has served as one of the most contentious issues in American environmental law. The latest proposal represents a high-stakes effort to bridge the gap between the rigid mandates of the high court and the practical realities of managing complex, interconnected hydrological systems.
A Four-Decade Regulatory Tug-of-War: The Chronology of Conflict
To understand the current proposal, one must view it as the latest chapter in a protracted legal saga. The ambiguity surrounding CWA jurisdiction stems from the statute’s failure to provide a precise, geographic definition for what constitutes a "navigable water."
The Rapanos Legacy
The path to the current uncertainty began in earnest with the 2006 Supreme Court case Rapanos v. United States. The court was deeply divided, producing no single majority opinion. Instead, Justice Anthony Kennedy proposed the "significant nexus" test, which allowed for federal protection of wetlands if they significantly affected the chemical, physical, and biological integrity of traditional navigable waters. Conversely, Justice Antonin Scalia advocated for a more restrictive approach, requiring a "continuous surface connection" to a relatively permanent body of water.
The Sackett Paradigm Shift
For years, the "significant nexus" test became the standard for agency enforcement. However, the 2023 Sackett v. EPA ruling effectively dismantled that framework. The Supreme Court adopted a standard aligning closely with Justice Scalia’s 2006 concurrence, ruling that wetlands must have a "continuous surface connection" to a relatively permanent body of water to fall under federal oversight.
The November 2025 Proposal and Resulting Confusion
In November 2025, the EPA and the Corps issued an initial rule attempting to codify the Sackett standard. However, the implementation proved problematic. The rule’s reliance on defining "wet seasons" to determine connectivity created massive operational uncertainty. Developers and landowners were left asking: What exactly defines a "wet season," and how do these climatic windows vary across diverse geographic regions, from the arid West to the humid Southeast? Larry Liebesman, a former Department of Justice attorney and senior advisor at Dawson & Associates, noted that this initial attempt failed to provide the "bright-line" clarity the industry desperately needed.
The September 2026 Supplemental Proposal: A Simplified Path?
The supplemental proposal released on September 4 is a strategic recalibration. Recognizing the administrative quagmire created by the November 2025 rule, the agencies are now proposing a more streamlined, simplified approach to identifying jurisdictional waters.
The core of this new proposal focuses on identifying "relatively permanent waters"—streams and rivers that flow year-round or consistently during specific, predictable seasons. Under the new guidelines, wetlands are only subject to federal permitting if they possess a continuous surface connection to these permanent waters.
"I think what they’ve tried to do is to come down with a more simplified approach that would make it easier for landowners to identify what are relatively permanent waters, what wetlands are contiguous and connected to those waters, and therefore federally regulated, and those that are not," Liebesman explained. By moving away from vague, climatically dependent definitions toward more objective, observable criteria, the agencies hope to reduce the time and expense associated with the jurisdictional determination process.
Industry Perspectives: The Quest for Regulatory Certainty
For the construction and infrastructure sectors, the primary concern has always been the delay and legal risk associated with ambiguous permitting requirements. Consequently, the latest proposal has garnered cautious optimism from trade groups.
Transportation and Infrastructure
Prianka Sharma, vice president and counsel of regulatory affairs at the American Road and Transportation Builders Association (ARTBA), believes the proposal offers a much-needed improvement. "Based on an initial review, the latest proposal will provide greater clarity on which transportation construction water features, including certain roadside ditches and drainage features, are subject to federal jurisdiction," she stated.
Sharma noted that by drawing a clearer line around seasonal and intermittent features, the proposal could significantly reduce the uncertainty that has long plagued transportation projects, where the inability to determine if a permit is required often leads to multi-year delays.
General Contracting and Development
The Associated Builders and Contractors (ABC) echoed these sentiments. Kristen Swearingen, vice president of government affairs, praised the EPA’s commitment to "regulatory certainty." For contractors, the goal is not necessarily to avoid environmental protection, but to ensure that the rules of the game are consistent, predictable, and aligned with the highest law of the land—the Supreme Court’s Sackett decision.
Environmental Alarm: The Risk of Eroding Protections
While industry groups welcome the streamlining, environmental advocates view the proposal as a regressive step that threatens the ecological health of the nation’s watersheds. The Natural Resources Defense Council (NRDC) and other conservation organizations argue that the new guidelines effectively create a loophole that could leave vast swaths of the country’s water supply vulnerable to pollution and destruction.
The "30-Day" Threshold
The primary point of contention is the agencies’ definition of "perennial" waters. Under the current proposal, a stream is considered protected if it flows every day of the year, but the rules allow for a single, intermittent interruption of up to 30 consecutive days. Critics argue this is a purely arbitrary threshold that fails to account for the ecological function of ephemeral streams.
The Impact on the American West
Jon Devine, group director of freshwater ecosystems at the NRDC, offered a scathing assessment of the proposal. According to internal analyses conducted by environmental groups, the proposed criteria would result in the loss of federal protections for the vast majority of streams in the western United States, where water flow is naturally intermittent but vital to the overall ecosystem.
"This proposal declares open season on the nation’s waterways," Devine stated. He argues that by limiting protection only to wetlands that are "indistinguishable" from a permanently flowing water body, the agencies are essentially abandoning the precautionary principle that has historically protected the chemical and biological integrity of downstream waters.
Implications: Looking Toward a Final Rule
The immediate future of the Clean Water Act rests on the upcoming public comment period. Once the proposal is officially published in the Federal Register, the public will have 30 days to weigh in. Given the history of this issue, the agencies are likely to be inundated with thousands of comments from stakeholders ranging from municipal water authorities and agricultural giants to environmental NGOs.
The Regulatory Clock
Larry Liebesman suggests that the EPA is operating under a compressed timeline, with the objective of finalizing the rule before the close of the current calendar year. This urgency is driven by the need to stabilize the federal permitting process and provide a definitive answer to the jurisdictional questions that have persisted since the Sackett ruling.
What Lies Ahead for Stakeholders
For developers and environmental planners, the next few months will be a period of intense scrutiny. The final rule will dictate:
- Permitting Requirements: Which projects will require a Section 404 permit under the Clean Water Act.
- Mitigation Costs: The financial burden of environmental mitigation for projects affecting non-jurisdictional versus jurisdictional waters.
- Litigation Risk: Whether the final rule will withstand the inevitable legal challenges from both industry groups seeking further deregulation and environmental groups seeking to restore broader protections.
The shift toward a "simplified" definition of WOTUS is, at its heart, an attempt to translate a complex legal doctrine into a functional administrative tool. Whether it succeeds in balancing the dual imperatives of economic development and environmental stewardship remains to be seen. What is certain, however, is that as long as the nation remains divided on the extent of federal authority over its waters, the legal battle will continue to flow through the courts, the regulatory agencies, and the construction sites of America.
