New Supplemental Notice of Proposed Rulemaking on Waters of the U.S. Definition
by Amy L Noel, PWS
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On September 4, 2026, the U.S. EPA released a new supplemental notice of proposed rulemaking on the updated “Waters of the U.S.” definition. This definition was initially published on November 20, 2025, with the intent to further define the waters that can be federally regulated under the Clean Water Act in accordance with the 2023 U.S. Supreme Court decision in Sackett v. Environmental Protection Agency. After an initial round of public comments, this recent supplemental notice provides further information on the proposed rule and is once again open to a public comment period.
The latest proposed rule change seeks to further clarify and define what streams qualify as a “relatively permanent water” and what constitutes a “continuous surface connection” regarding wetland jurisdiction. This new supplemental was released in response to comments received during the first public comment period.
In the latest supplemental notice, perennial or continuously flowing streams would be considered a jurisdictional “relatively permanent water,” as long as they do not dry up for greater than 30 days in a single period, once per year. This would eliminate intermittent streams from federal jurisdiction and the wetlands that directly share a border with them, which are currently considered to be jurisdictional and under federal Clean Water Act protection.
Wetlands would be considered federally jurisdictional only if they share a “continuous surface connection” defined as visible surface water flow to a perennial stream which does not dry up for greater than 30 days in a single period, only once per year. If a wetland does not have surface water visible for a continuous period as defined above, it would not be considered jurisdictional and under federal Clean Water Act protection. If implemented as stated in the supplemental, portions of the same wetland may not be protected under the Clean Water Act.
This has far-reaching implications for future protections of wetlands and would leave most wetland protections under the control of individual state regulations. Not all states have isolated wetland laws, and all states vary greatly in the levels of protection for waterways not federally protected. Indiana regulates impacts on some isolated wetlands. In Indiana, this would mean more wetlands would fall under the protections outlined in the Indiana State Regulated Wetlands Law.
As it turns out, there have been two recent rollbacks of isolated wetland protections in Indiana. In 2021, under Senate Enrolled Act 389, changes to the 2003 State Regulated Wetlands Law included exempting all Class I wetlands from protections, reducing Class II wetland protections by allowing more wetland acreage to be impacted without a permit or mitigation, adding additional agricultural exemptions for wetland impacts for farm tile maintenance and cropland development (within five years), and eliminating ephemeral streams from state protection. In 2024, under House Enrolled Act 1383, additional rollbacks to isolated wetland protections were implemented including the elimination of some special wetland types being considered as Class III wetlands and creating size-based exemptions for Class II wetlands depending on their location within or outside of municipal boundaries.
The final rule will have lasting effects on the future of wetland protections both nationwide and within Indiana. With a reduction in both Indiana state and federal regulatory protections over the last five years, further wetland loss is expected should the proposed rule be implemented as written. Comments on the new proposed rulemaking are due by October 9, 2026.
Amy L. Noel is the Practice Lead for Metric’s Natural Resources division. Learn more about all our Natural Resources services HERE.
Archaeology Month
A total of 44 U.S states have a dedicated month each year to celebrate and raise public awareness about archaeological resources. September is Indiana’s Archaeology Month. Metric Environmental, along with universities, museums, organizations, and individuals throughout the state, host a variety of programs. These programs can include social media posts, archaeological lab open houses, artifact identifications, lectures on archaeological topics, archaeological excavations, and more. Archaeology Month helps to teach more about archaeology, archaeological sites, and the laws that protect those sites. The goal of every archaeology month is to increase public awareness and to help minimize myths and misconceptions associated with archaeology. Indiana Archaeology Month is a statewide celebration that helps Hoosiers continue to discover what archaeology can reveal about our state’s heritage and history.
Welcome New Metric Team Members!
Recent Webinar: Phase I and Phase II Environmental Site Assessments Webinar
Assessment + Remediation Practice Lead, Joe Brodowski did a great job covering Phase I and Phase II Environmental Site Assessments and answered questions like, why are they necessary, how they help, and what are the steps?
Metric has helped numerous clients manage and mitigate various environmental issues in order to help identify and provide understanding of Recognized Environmental Conditions (RECs), controlled recognized environmental conditions (CREC), historical recognized environmental conditions (HRECs), and potential vapor encroachment conditions (VEC) associated with properties.
Click Here to learn more and watch the RECAP VIDEO!
Upcoming Webinar: Trekking Through Wetland and Stream Delineations
On December 3, Natural Resources Senior Project Manager, Alex Gray will be addressing topics such as:
Why do we care about wetlands? What defines a wetland? When do you need a waters delineation? Wetland delineations identify areas that need protection, and the results help our clients avoid or minimize impacts to these waterways. We’ll discuss why providing baseline data of what’s onsite contributes to wetland and stream preservation and mitigation efforts. Wetland delineations aren’t for the faint of heart, it’s hard work, and you must like getting muddy! However, accessing environments that most people would steer clear of is educational and exciting! Please jump in with us as we trek through these topics together!
Keep an eye out for registration details to come!
