EPA and Army Corps Publish Supplemental WOTUS Rulemaking Notice
On September 9, 2026, the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers published a Supplemental Notice of Proposed Rulemaking on the updated definition of “Waters of the United States” (WOTUS). The notice reopens comment on a handful of specific definitions from the agencies’ November 2025 proposal, while leaving the rest of that proposal unchanged. The comment period closes October 9, 2026.
What’s Being Reconsidered
The Supplemental Notice seeks input on four specific pieces of the WOTUS definition:
- Perennial — proposed to mean water that stands or flows continuously every day of the year under ordinary conditions, with an alternative definition of surface water flowing continuously year-round
- Relatively permanent — proposed to cover only perennial waters, with an exception for anomalous events like drought where a water body could go dry for up to thirty consecutive days without losing that status
- Continuous surface connection — proposed to mean perennial surface water in a wetland connected to a jurisdictional water so closely that it’s difficult to tell where one ends and the other begins, with the same thirty-day drought exception
- Adjacent — the supplemental notice takes comment on deleting this definition entirely, and on limiting jurisdictional wetlands to only those indistinguishable from a traditional navigable water
EPA and the Army acknowledge that these alternatives could significantly reduce the extent of streams and wetlands considered WOTUS compared to the current baseline, with the largest effects expected in the arid West.
What This Means for Florida Project Planning
Florida’s wetlands are generally not the arid-West type most affected by these particular definitional shifts, but the direction is worth tracking closely. A narrower “adjacent” definition, or a stricter perennial and relatively-permanent standard, changes which wetlands trigger federal Section 404 jurisdiction and which fall to the state alone. That has direct implications for permitting timelines, credit demand, and where federal versus state-only mitigation credits are required.
Agencies have asked commenters not to resubmit input on the original November 2025 proposal. Both the November comments and anything submitted on the Supplemental Notice will be considered together as the agencies work toward a final rule. Comments on the supplemental proposal are due October 9, 2026, and can be submitted through Regulations.gov under Docket ID EPA-HQ-OW-2025-0322.
Have questions about how a shifting WOTUS definition could affect your project’s permitting path or mitigation credit needs? Contact The Mitigation Banking Group for guidance.
