The Trump administration’s strategy regarding the scope of the “waters of the United States,” which defines the geographic jurisdiction of the Clean Water Act, is coming into focus, but true clarity appears a long way off.
The US Environmental Protection Agency and US Army Corps of Engineers issued new guidance in March regarding which wetlands are included in the “waters of the United States” and announced a public input process under the Administrative Procedure Act for potential rulemaking.
These actions don’t create major changes in the short term, other than excluding some wetlands from regulation by the CWA. For the longer term, the administration hasn’t articulated how it might change its regulations, but a new rulemaking process likely will be lengthy and will be affected by ongoing judicial rulings regarding the scope of the “waters of the United States.”
Current WOTUS Scope
The CWA regulates discharges into the “waters of the United States.” Precisely what constitutes those waters has been defined in a series of regulations issued by the EPA and the Corps over decades.
These regulations have been issued by one presidential administration, enjoined by courts and rescinded by succeeding presidential administrations. The US Supreme Court has also intervened with several decisions interpreting the definition. The lack of long-term clarity has affected many property owners and project sponsors because the need for a CWA permit often triggers the need for other lengthy federal environmental reviews.
In May 2023, the Supreme Court issued Sackett v. EPA, addressing which wetlands are regulated under the CWA. Sackett adopted and expanded upon the plurality decision in Rapanos v. United States, and provided the following test:
- The CWA extends only to wetlands that are “as a practical matter indistinguishable from waters of the United States.”
- The party asserting jurisdiction over adjacent wetlands must establish that the adjacent body of water constitutes “waters of the United States,” (i.e., a relatively permanent body of water connected to traditional interstate navigable waters).
- The wetland must have a continuous surface connection with that water, making it difficult to determine where the “water” ends and the “wetland” begins.
In January 2023, the Biden administration issued regulations that tracked language from the two operative opinions in Rapanos (Justice Antonin Scalia’s plurality opinion and Justice Anthony Kennedy’s concurring opinion). The regulations don’t define key terms such as “continuous surface connection” (although the agencies provided guidance in the Federal Register preamble) and also don’t include language about the distinguishability of waters and wetlands.
After Sackett was issued, the agencies issued a “conforming rule” in September 2023 that struck language from Kennedy’s opinion that was rejected in Sackett, but otherwise made no changes.
Several lawsuits were filed that challenge the Biden administration regulation. As a result, the regulation was enjoined in 26 states while the courts decide the cases. In those states, the agencies apply the pre-2015 regulatory regime. For the remaining states, the Biden administration regulation is in effect.
There also have been several cases that apply Sackett to the facts of specific properties. Some of these cases have generally adopted the agencies’ longstanding interpretation of the Rapanos plurality to regulate most waters and wetlands. Other cases have held that Sackett has reduced the scope of the “waters of the United States” and have interpreted key terms differently than the agencies.
Trump Administration’s Announcements
On March 12, the EPA and the Corps announced the Trump administration’s initial strategy to address the scope of the “waters of the United States.”
First, the agencies issued a guidance memorandum concerning the meaning of the term “continuous surface connection” as used in Sackett. The memorandum mostly quotes language from Sackett, Rapanos and previous agency guidance, and emphasizes that wetlands are only regulated if they abut or touch another regulated waterbody.
The memorandum makes one substantive change: It rescinds language in the preamble to the January 2023 regulation that wetlands have a continuous surface connection “if the wetlands are connected to these [other regulated] waters by a discrete feature like a non-jurisdictional ditch, swale, pipe or culvert.” The memorandum doesn’t explain whether a ”continuous surface connection” requires the presence of surface water, whether waters and wetlands must be indistinguishable, and also doesn’t address what waterbodies constitute “relatively permanent waters.”
Second, the agencies issued a Federal Register notice and invited the public to offer recommendations on how to define key terms related to the “waters of the United States.” The notice doesn’t propose any specific change to the regulations. Instead, it announced the agencies will hold listening sessions and invited the public to submit written recommendations regarding the scope of the vaguely defined terms.
The deadline to submit written recommendations was April 23, and more than 3,000 individuals and organizations submitted written comments. Listening sessions are scheduled to continue through May.
Immediate Practical Effects
In the short term, the primary effect of the Trump administration’s actions is to reduce the regulation of wetlands that don’t directly abut regulated waterbodies but are connected by culverts, pipes and non-jurisdictional ditches. This may not seem like much, but in practice, it could result in many wetlands being excluded from CWA regulatory jurisdiction.
The EPA and Corps’ position has been that the “waters of the United States” include wetlands that directly touch the edge of regulated waterbodies such as perennial streams. This means that if a wetland delineation shows some wetland soils coming down to the edge of a regulated waterbody, the agency would assert jurisdiction over the entire wetland, including areas at a distance from the waterbody.
The agencies’ strategy in litigation has been to try to connect a wetland on a defendant’s property to other wetlands that touch a regulated waterbody at some location, to gain jurisdiction.
In certain situations, however, a wetland may be located near a waterbody but on the other side of a berm, road, or some other kind of barrier. For years, the agencies asserted jurisdiction over such a wetland on the theory that it is “adjacent” to the waterbody.
In the first Trump administration, the agencies promulgated a regulation stating that such a wetland wouldn’t be regulated unless water somehow crossed the barrier, such as through a culvert, pipe or pump, in which case the wetland would be regulated.
The Biden administration continued the concept of asserting jurisdiction where there is such a connection, stating in its January 2023 regulation preamble that a wetland has a sufficient connection to a regulated waterbody if water can move through “a discrete feature like a non-jurisdictional ditch, swale, pipe or culvert.” However, the Supreme Court in Sackett stated that “a barrier separating a wetland from a water of the United States would ordinarily remove that wetland from federal jurisdiction.”
Based on that language in Sackett, the new Trump administration guidance states a wetland that doesn’t directly abut a regulated waterbody isn’t regulated, even if it is connected by a culvert, pipe, or non-jurisdictional ditch. This position is even more restrictive than the regulation adopted in the first Trump administration.
In practice, this change likely will cause the agencies to assert jurisdiction over fewer wetlands.
It’s common for there to be wetlands in the general vicinity of streams where there also are berms, roads, ditches, pumps and culverts. Corps personnel typically look to see if a wetland comes down to the edge of a stream or ditch, and if there is a berm or an area of upland between them, they try to find a connection.
Sometimes the agencies will claim jurisdiction over a wetland based on a circuitous path of ditches that lead through culverts and eventually reach a regulated water. The new guidance indicates that the agencies should no longer find CWA jurisdiction based on that logic.
Future Policy Directions
The Trump administration hasn’t indicated what other changes it may make to the regulations defining the “waters of the United States,” but a few things seem likely.
First, any change to the regulations won’t happen quickly. The first Trump administration needed years to issue a final rule that redefined the “waters of the United States,” because notice-and-comment rulemaking procedures are time consuming and the agencies must prepare for the inevitable court challenges. The administration hasn’t even proposed specific changes to the regulations, so it likely will be months (at least) before the agencies identify proposed revisions to the regulations.
All of this means that the regulated community will have to live with the current regulations for the foreseeable future.
Second, the agencies appear to want a revised rule that’s durable. The pattern for the past decade has been that one administration issues a regulation defining the “waters of the United States,” only to have it repealed and replaced by the next administration.
When EPA Administrator Lee Zeldin announced the agencies’ actions, he repeatedly stated the administration wants to break that pattern and come up with a revised regulation that will stand the test of time. (Officials in the Biden administration said the same thing.)
The new administration appears to want to do that by staying as close as possible to the language in the Supreme Court decisions, which means that new proposals may primarily interpret words and concepts in those cases.
There may be more continuity with past practice than many people expect. One curious aspect of the new announcements is that they appear to maintain the agencies’ longstanding approach to wetland jurisdiction that focuses on the concept of abutment.
The language about the regulation of “abutting” wetlands comes from the Supreme Court’s decision in United States v. Riverside Bayview Homes, Inc. The agencies have used that language to claim a wetland is regulated in circumstances where wetland soils touch a regulated waterbody, even if no surface water is present.
The Rapanos plurality and Sackett didn’t use this formulation for determining whether a wetland is regulated, but instead stated there must be a “continuous surface connection” and suggested that means the presence of surface water. This latter formulation is more restrictive regarding which wetlands are regulated, but the new administration appears to be staying with the previous formulation.
When Zeldin said the agencies would regulate “wetlands that abut or are adjacent to relatively permanent waters,” he could have been quoting his immediate predecessor.
Third, whatever the agencies do, it will be against the backdrop of ongoing litigation. Since the Supreme Court issued Sackett, there have been several decisions applying the case to the facts of specific properties. These judicial decisions arise from government enforcement actions, citizen suits and property owner challenges to jurisdictional determinations.
Even if the agencies bring fewer enforcement actions, there still will be cases that address the “waters of the United States” brought by other parties. Courts in those cases have interpreted the words used by the Supreme Court, which is the same thing that the agencies presumably will do in rulemaking.
For instance, in United States v. Sharfi, the court ruled that a continuous surface water connection is required for there to be jurisdiction, which undercuts the agencies’ historical reliance on the concept of abutment as sufficient for jurisdiction. That and other cases also indicate that the “indistinguishability” language in Sackett needs to be given effect in any formulation of what wetlands are regulated.
As this body of case law grows, it may shape or limit the agencies’ options in how they keep or modify the regulations. This will be especially true if the rulemaking process is lengthy and if the resulting regulations are enjoined because of legal challenges.
The Trump administration has pledged to reduce the scope of CWA regulation, but its changes likely won’t come as quickly or be as sweeping as some people expect. The administration’s initial announcement is a cautious first step in what likely will be a lengthy rulemaking process.
Reproduced with permission. Published May 20, 2025. Copyright 2025 Bloomberg Industry Group 800-372-1033.
