Trump administration officials declared last week that their proposed waters of the U.S. rule would end decades of regulatory ping pong and legal whiplash.
But the draft rule redefining which waters and wetlands are covered by the Clean Water Act also introduces a concept that some environmental lawyers are already questioning: wet season.
The phrase is not referenced in Sackett v. EPA, the 2023 Supreme Court ruling that administration officials cited as the basis for rewriting the WOTUS regulation. Yet that’s a key term in the new rule. In order to be federally regulated, EPA and the Army Corps of Engineers proposed requiring that wetlands and waters contain surface water at least for the duration of the “wet season.”
“It’s not something that otherwise has been codified in regulation in prior rulemakings by the agencies,” said Damien Schiff, a senior attorney at the conservative Pacific Legal Foundation who argued the Sackett case. “It’s also not really something that plays a role in wetland delineation itself, which is something the rule preamble gets into.”
Since its enactment, the Clean Water Act has extended to “waters of the U.S.,” a phrase understood to include rivers, oceans and lakes that can be traversed by boat but that is less clear with respect to wetlands, ditches and small streams.
Sackett asserted that only wetlands with a “continuous surface connection” to a “relatively permanent” body of water would be covered by the law. Environmentalists and scientists viewed the ruling as a major threat to clean water, noting that wetlands help hold back floodwaters and filter out pollutants and that ephemeral streams can substantially affect water quality.
In its new draft rule, the Trump administration defined “relatively permanent” as rivers, streams and other waters that flow year-round or at least for the duration of a “wet season.” Wet season itself is not defined. Administration officials stressed that the interpretation was consistent with Sackett.
But Mark Sabath, a senior attorney at the Southern Environmental Law Center, said the proposal did not fully explain how the wet season would be determined.
“It seems like something the agencies sort of made up,” Sabath said. “If the point of the rule is to bring clarity and certainty to this area, the way the agencies proposed to do this does just the opposite.”
The agencies argued that wet season as a concept can be understood “by both ordinary citizens and trained professionals,” per the proposal.
EPA Administrator Lee Zeldin stressed during a news conference last week that the agencies would welcome feedback on the wet season issue.
Members of the public have until Jan. 5 to comment.
Asked about the rule’s durability, Zeldin said this rewrite of WOTUS was inherently different from prior ones because of Sackett.
“That’s one of the big differences from the past. Now you have the Supreme Court weighing in, and we’re following Sackett very closely,” Zeldin said. “The words are being interpreted strictly. We’re sticking to the prescriptive language of the Supreme Court decision.”
Other vulnerabilities
To determine whether waters and wetlands are “wet” enough to count as a WOTUS, the agencies intend to use a model developed by the University of Delaware, the web-based Water-Budget Interactive Modeling Program (WebWIMP). The tool measures the “climatologically averaged monthly water balance” of a given location, said Kenji Matsuura, a researcher currently based in Japan who developed the tool, in an email.
Betsy Southerland, a former career scientist in EPA’s water office, said using that method could be problematic, because it does not account for changing precipitation patterns due to climate change. The wet season standard could also knock out nearly all wetlands and waterways in the arid West, Southerland said.
“It will definitely be litigated because, basically, you’re going to eliminate millions of acres of wetlands and many of the intermittent streams,” Southerland said. “But out West, I don’t know if you’re going to have anything left.”
Not all legal experts agree that “wet season” is an entirely new concept. Neal McAliley, an attorney at Carlton Fields who has represented farmers, landowners and businesses in WOTUS enforcement cases, said it seemed similar to a concept introduced in 2008 guidance.
Specifically, EPA and the Army Corps at that time asserted that tributaries should generally flow at least “seasonally” to be considered a WOTUS, McAliley said.
“This proposed rule does not do a major surgery to the structure of the regulation,” he said.
Others said the concept would be difficult to implement in practice. Landowners and even the agencies themselves might not have sufficient data to determine whether a waterbody is inundated for the full duration of a wet season, said Jim Murphy, director of legal advocacy at the National Wildlife Federation.
Also, in dry states like New Mexico, the wet season generally occurs in January, February and March, Murphy said. But precipitation usually occurs in the form of snow and streams often do not flow until the spring, when the snow melts, he said.
“The proposed rule appears to be written to say that all those streams would be out,” Murphy said. “I think, to be quite honest with you, it’s designed to be that way, because it makes it very easy for someone to impact a water and then claim, ‘Hey, it’s not wet during the wet season.'”
The Sackett ruling left open many questions about the Clean Water Act’s scope, said Pat Parenteau, emeritus professor at Vermont Law and Graduate School. Predicting that the rule will be litigated, Parenteau noted that federal courts — and perhaps even the Supreme Court — will need to determine whether they agree with the Trump administration’s interpretation.
That’s true with respect to the agencies’ proposed definition of “continuous surface connection,” he said. For the first time since the Clean Water Act’s enactment, the agencies asserted in the proposal that a human-made obstruction — including a tunnel, a debris pile or field of boulders — could remove upstream waters from the federal government’s purview.
“Bottom line: We are a long way from knowing whether this proposed rule survives,” Parenteau said.
Parenteau noted that Trump’s proposal is also missing an important legal tool that has helped past administrations defend their WOTUS rules in court — Chevron deference. Last year, the Supreme Court overturned the doctrine, which for 40 years had given agencies like EPA the benefit of the doubt in legal battles when the text of a statute was unclear.
“This is a question of how to interpret the Sackett opinion,” Parenteau said. “EPA gets no deference on that.”
He said that once the Trump rule is finalized, he expects to see a multiyear legal battle like the ones that have followed every WOTUS regulation.
“The only thing that would stabilize anything is congressional action,” Parenteau said, “and that doesn’t look like it’s anywhere close to happening.”
Schiff, the Pacific Legal Foundation attorney, said he expects legal fights to play out over how the agencies apply the rule. But overall, if the rule is finalized, it could provide “dramatic relief” to the landowners his firm is currently representing in about half-a-dozen WOTUS-related cases, he said.
“It requires a wait-and-see attitude with respect to this wet season concept,” he said.
Sabath noted that the draft rule does not contain a full analysis of the costs and benefits of the proposed changes. While the agencies said they were open to suggestions for how to monetize total benefits and costs, the proposal only contemplates how the rule could affect “the cost of permitting,” Sabath said.
“They have no discussion at all about the costs to communities, the environment, increased flooding, threats to drinking water, or threats to businesses and recreation that depend on clean waters and healthy wetlands,” he said. “That is a huge gap in the cost-benefit analysis they do.”
