By STAFF REPORTS
The federal definition of “waters of the United States” has spent most of the last 20 years in motion. Administrations have written and rewritten it. Courts have stayed it, vacated it, narrowed it, revived older versions and sent the agencies back to the drawing board. Regulated parties have been left to work through a patchwork in which the operative federal definition can depend on the state where a project is located.
EPA and the U.S. Army Corps of Engineers are now trying again.
The agencies’ latest proposal, published in the Federal Register on Nov. 20, 2025, would revise the definition of WOTUS to conform to the U.S. Supreme Court’s 2023 decision in Sackett v. EPA. The public comment period closed Jan. 5. A final rule is expected later in 2026.
That raises the practical question: What will survive into the final rule?
The Florida Specifier asked a small group of Florida-based practitioners with WOTUS experience to react to a set of predictions about the proposed rule. The responses received were consistent — the core Sackett framework appears well-established. The proposed “wet season” methodology is the most likely piece to change.
THE CORE SACKETT FRAMEWORK IS LIKELY TO STAY
The most stable part of the proposal, experts believe, is the basic legal architecture drawn from Sackett. That means federal jurisdiction will continue to focus on traditionally navigable waters, relatively permanent waters and wetlands, which abut the WOTUS, and are indistinguishable from those waters.
The Supreme Court rejected the “significant nexus” test and directed the agencies back toward a more limited definition tied to relatively permanent waters and wetlands that are, as a practical matter, indistinguishable from those waters.
It appears that the final rule will retain:
• The focus on relatively permanent waters;
• The continuous surface connection standard;
• The proposed tributary definition requiring relatively permanent flow and a downstream connection to a traditional navigable water;
• The exclusion of groundwater as a jurisdictional connector;
• The exclusion of ditches constructed entirely in dry land; and
• Continued recognition of the prior converted cropland exclusion.
The Florida experts we asked generally agreed with that premise and while that does not mean every word of the proposed rule will remain untouched, the foundation appears durable.
TRIBUTARIES: A NARROWER AND MORE STRUCTURED TEST
One of the most important changes in the proposal is the definition of “tributary.”
Under the proposed rule, a tributary must have relatively permanent flow and must connect to a downstream traditional navigable water. A tributary may pass through natural features, such as beaver dams or debris piles, or artificial features, such as culverts, ditches, pipes, tunnels, pumps or tide gates. This is true even if those features are not jurisdictional on their own, though those features must convey relatively permanent flow.
That last point is significant because if flow becomes non-relatively permanent downstream, federal jurisdiction would be severed upstream. In other words, jurisdiction cannot simply leap across a dry or ephemeral segment to reach an upstream feature.
Experts believe this approach is likely to survive because it directly implements the high court’s direction. It also gives regulators and applicants a clearer way to analyze tributaries than the older case-by-case significant nexus framework. Whether it is always easy to apply is another question. But it is a more structured test than the agencies have used in some prior rules.
GROUNDWATER SHOULD REMAIN EXCLUDED AS A JURISDICTIONAL CONNECTOR
The proposed rule excludes groundwater as a basis for connecting otherwise non-jurisdictional features to WOTUS. That provision is also likely to remain.
Some commentators have suggested potential confusion between this exclusion and the Supreme Court’s earlier decision in County of Maui v. Hawaii Wildlife Fund. That concern is understandable, but the two cases address different parts of the Clean Water Act. Maui involved the NPDES program and whether a point source discharge through groundwater could require a permit when the groundwater pathway was the functional equivalent of a direct discharge to navigable waters. Sackett and the WOTUS rule address the geographic scope of federal jurisdiction. Groundwater may matter as a discharge pathway in a Section 402 case. It does not follow that groundwater can be used to extend WOTUS jurisdiction over wetlands or other waters that lack the surface connection required by Sackett.
Those two principles can operate at the same time.
STORMWATER FEATURES AND WASTE TREATMENT SYSTEMS DESERVE ATTENTION
Two other areas that may get close attention: stormwater control features and waste treatment systems.
The 2020 Navigable Waters Protection Rule expressly excluded stormwater control features constructed or excavated in upland or non-jurisdictional waters to convey, treat, infiltrate or store stormwater runoff. Engineers, local governments and developers have strong practical reasons to support restoring that exclusion.
Stormwater systems are not natural waters. They are engineered infrastructure built to meet regulatory requirements, manage runoff, reduce flooding and improve water quality. Treating them as potential WOTUS can discourage maintenance and retrofits — the very activities needed to keep them functioning.
A similar argument applies to waste treatment systems. Some believe that if a feature is designed and operated as part of a treatment system, the law should not create uncertainty by treating the treatment feature itself as a jurisdictional water. That is especially applicable in Florida, where stormwater infrastructure is deeply integrated into environmental permitting, land development, roadway design, flood protection and water quality compliance.
DITCHES CONSTRUCTED IN DRY LAND ARE LIKELY TO REMAIN EXCLUDED
The proposed exclusion for ditches, including roadside ditches, constructed entirely in dry land is likely to survive. It is simple, observable and administrable.
Ditches have been one of the most persistent sources of WOTUS confusion. A ditch may be a channelized natural tributary in one setting, a roadside drainage feature in another and an agricultural or stormwater conveyance somewhere else. The proposed rule draws a line: if the ditch was constructed entirely in dry land, it should not be treated as WOTUS.
The final rule may also clarify that temporary flow in response to precipitation does not defeat the exclusion. Many upland ditches are designed to carry stormwater. That does not transform them into federal waters. Maintenance, repair, reconstruction and modification of excluded ditches should also remain excluded.
STATE WETLAND PROGRAMS POST-SACKETT
The narrowing of federal jurisdiction does not mean wetlands are unprotected. It means state programs matter more.
Florida has regulated wetlands for decades through state law and the Environmental Resource Permitting program. The state does not depend on WOTUS to protect wetlands and the narrowing of the federal definition does not eliminate state wetland regulation.
That distinction is often missed in national news coverage. Some states may need to expand their own wetland laws if they want to backfill federal jurisdiction after Sackett. Other states, including Florida, already have robust programs in place.
That is not an argument against wetland protection. It is an argument for locating authority where the Constitution and the Clean Water Act place it. Congress’s authority is limited to navigable waters. States have broader police powers to regulate land and water resources within their borders.
CONTINUOUS SURFACE CONNECTION MAY BE REFINED, NOT REBUILT
Experts were split on whether the continuous surface connection standard may be revised before finalization.
The continuous surface connection standard is central to Sackett. The agencies have already moved away from earlier interpretations that allowed discrete features, such as ditches or pipes, to establish jurisdictional connections to wetlands that did not physically abut jurisdictional waters. The proposed rule is much closer to the Supreme Court’s formulation than a 2023 rule.
Still, the final rule may need additional clarification. The risk is not that the agencies abandon continuous surface connection, but that field implementation again becomes elastic enough to generate uncertainty and litigation. Sackett requires a wetland to be practically indistinguishable from a jurisdictional water. This test actually comes from a written Supreme Court decision, United States v. Riverside Bayview.
It’s possible the wet-season concept may survive in some form. The agencies may add clearer guardrails, adopt a more objective duration threshold, define a hierarchy of acceptable evidence or clarify that field-observed surface flow carries more weight than broad climatological modeling.
Our prediction was that the wet-season methodology is least likely to survive unchanged. The expert responses confirmed that view.
WHAT’S NEXT
The final WOTUS rule will probably not end the litigation. But the proposal does represent a serious effort to respond to Sackett and provide clearer jurisdictional lines.
Based on the proposal, prior litigation and the responses from Florida experts, the likely outcome is a final rule that keeps the core Sackett framework intact while revising the wet-season methodology and possibly clarifying implementation details around tributaries, ditches, stormwater features and waste treatment systems.
The most important question is not whether the final rule uses the right legal vocabulary. The question is whether the final rule can be applied predictably by regulators, engineers, landowners and consultants without recreating the expert-driven uncertainty that got WOTUS into trouble in the first place.
