Sackett v. Environmental Protection Agency, 598 U.S. 651 (May 25, 2023), is the Supreme Court decision that narrowed which wetlands are regulated as “waters of the United States” under the Clean Water Act. It is the reason a mapped wetland on a Gulf Coast site may no longer be a federal wetland under Section 404 of the Clean Water Act.
It is not a permit. It is not a delineation. It affects both of those processes in that it is the current test the Corps and EPA have to use when they decide jurisdiction.
How the court defined Waters of the US
The Court rejected the “significant nexus” test. A wetland is not federal just because it has some hydrologic or ecological connection to a navigable water.
The Court held that wetlands are waters of the United States when two things are true:
- The adjacent body of water is itself a water of the United States (a relatively permanent water, or a traditional navigable water).
- The wetland has a continuous surface connection to that water, so that as a practical matter it is difficult to tell where the water ends and the wetland begins.
In short: relatively permanent water, plus a surface connection that makes the wetland indistinguishable from that water.
How the agencies are applying this ruling
In September 2023 the agencies issued a conforming rule that removed significant nexus from the 2023 WOTUS definition.
On March 12, 2025, EPA and the Army issued a joint field memo on “continuous surface connection.” They are reading it as abutting or touching. Wetlands separated by uplands, a berm, a dike, or a similar feature do not qualify on that connection alone. Guidance that treated a discrete feature — a pipe, a culvert — as enough to create the connection was rescinded.
That memo applies to the regulatory regimes now in effect. It does not automatically reopen older approved JDs. A new AJD requested now will be written under the current reading.
The agencies have also been writing a longer WOTUS replacement rule (a 2025 proposal, with a 2026 supplemental notice). That is not the field test today. Until a final rule is in force, Sackett plus the 2025 abutment memo is what the USACE districts are using.
What it changes on a Gulf Coast site
More isolated and bermed-off wetlands fall out of 404. Pine-flatwoods depressions, interdunal swales, and wet flats that do not touch a relatively permanent water are the usual examples. Tidal creeks, bayous, and wetlands that actually abut those waters are still in.
It does not erase state 401 water quality certification, coastal consistency, or Florida ERP. It does not erase floodplain rules. It does not tell you that you can fill.
It also does not replace the delineation. You still have to map the wetland before anyone can honestly argue isolation or abutment.
What it does not change
- Section 404 still applies to discharges of dredged or fill material into waters that are jurisdictional.
- Section 10 still applies to work in navigable waters.
- Nationwide vs individual is still a permit question, not a Sackett question.
- An approved JD is still how you get the Corps to say a feature is out.
How we use it
We do not write “Sackett says you can fill” on a proposal. We delineate, look at the actual connection, and tell you whether an approved JD is worth asking for. Sometimes it is. Sometimes the wetland is obviously abutting a tidal creek and you are wasting a year.
Cypress Environment & Infrastructure works from Biloxi, Mobile, and Pensacola, in the Mobile, Vicksburg, Jacksonville and New Orleans Districts. Office hours are Monday–Friday, 9 a.m.–5 p.m.
See What is a jurisdictional determination? and What are isolated wetlands?.