It has been three years since the U.S. Supreme Court decided the case of Sackett v. Environmental Protection Agency, 598 U.S. 651 (2023). Subsequent to the issuance of that opinion, the definition of "waters of the United States" (WOTUS) under the Clean Water Act (CWA) has undergone significant change, which remains ongoing. Developers, landowners, farmers, and businesses should understand how the legal landscape has shifted and what new regulatory proposals may mean for their operations. This E-Brief summarizes the Sackett decision, the agency regulatory response, ongoing legal challenges, and the November 2025 proposed rule that may further reshape federal jurisdiction over the nation's waters.
- Sackett v. EPA: The Supreme Court Narrows WOTUS
In Sackett v. EPA, the Supreme Court was faced with a question that has been at the heart of many legal and regulatory quandaries for decades: what does "the waters of the United States" mean under the CWA? The case arose when Michael and Chantell Sackett purchased property near Priest Lake, Idaho, and began backfilling their lot with dirt in preparation for building a home. The EPA informed them that their property contained jurisdictional wetlands classified as WOTUS and that their backfilling violated the CWA by discharging pollutants into the WOTUS, threatening penalties of over $40,000 per day.
The EPA classified the Sacketts' wetlands as WOTUS because they were located near a ditch that fed into a creek, which fed into Priest Lake, which is a navigable, intrastate lake. The Agency relied on the "significant nexus" test previously established in Rapanos vs. United States, 547 U.S. 715 (2006), which broadly assessed whether wetlands, alone or in combination with similarly situated lands, "significantly affect the chemical, physical, and biological integrity" of navigable waters.
The Court rejected the significant nexus and instead adopted a two-part test for wetlands jurisdiction: first, the adjacent body of water must constitute a "water of the United States," which is a relatively permanent body of water connected to traditional interstate navigable waters; and second, the wetland must have a "continuous surface connection" with that water, making it difficult to determine where the water ends and the wetland begins.
This new test would drastically reduce the number of wetlands that receive federal protection under the CWA.
- The September 2023 Conforming Rule
Sackett was decided following years of regulatory back-and-forth between different presidential administrations to the definition of WOTUS. Most recent to the decision, in November 2021, the EPA and U.S. Army Corps of Engineers (“USACE”) announced a proposed rule to revise the definition of WOTUS. Over a year later, in January 2023 a final rule revising the definition was published in the Federal Register, which then went into effect on March 20, 2023 (the “January 2023 Rule”), mere months before the Sackett decision.
Even before Sackett was decided, the January 2023 Rule, which utilized the significant nexus test, faced legal challenges from a coalition of states. Federal courts in Texas and North Dakota issued preliminary injunctions blocking the rule in a combined 26 states, finding the states were likely to succeed on the merits of their claims. See Texas v. U.S. Env’t Prot. Agency, 662 F. Supp. 3d 739 (S.D. Tex. 2023); West Virginia v. U.S. Env’t Prot. Agency, 669 F. Supp. 3d 781 (D.N.D. 2023).
Simultaneous with the ongoing legal challenges, and in response to the decision in Sackett, the EPA and USACE issued a final rule to amend the January 2023 Rule definition of WOTUS, effective September 8, 2023 (the “September 2023 Conforming Rule”) (88 Fed. Reg. 61,964), at 40 C.F.R. § 120.2 and 33 C.F.R. § 328.3. The rule aligned the agencies' regulations with the Court's holding.
The agencies removed the significant nexus test from the WOTUS definition, leaving the continuous surface connection test as the qualifying criterion for wetlands. They redefined the term "adjacent" to mean "having a continuous surface connection," directly tracking the Sackett standard. Finally, the agencies removed "interstate wetlands" from the WOTUS definition, consistent with the Court's conclusion that "waters" refers to open waters and not wetlands simply because they are interstate. Eight explicit exclusions were maintained, including ditches without permanent flow, swales and erosional features, water treatment systems, prior converted cropland, and artificially irrigated acres.
The injunctions issued in Texas and North Dakota remained in place when the September 2023 Conforming Rule was issued, creating a patchwork: the agencies implement the January 2023 Rule in 24 states and D.C., while applying the pre-2015 regulatory regime in the remaining 26 states.
Suffice it to say, keeping up with the fluctuations in CWA regulatory changes and legal ramifications amounted to a full-time job immediately before and after the Sackett decision.
- The March 2025 Guidance
On March 12, 2025, the EPA and USACE issued a joint guidance document to clarify the proper implementation of "continuous surface connection" under the WOTUS definition. This memo's primary objective was to provide "…national consistency and eliminate confusion about the scope of ‘adjacent wetlands’…"
Significantly, the guidance rescinded prior agency interpretations that had allowed "discrete features" (such as non-jurisdictional ditches, swales, pipes, or culverts) to establish a continuous surface connection between a wetland and a jurisdictional water. The agencies concluded that unless a wetland directly abuts a requisite jurisdictional water, it cannot be considered a jurisdictional adjacent wetland under Sackett.
As a guidance document, however, the memo is not legally binding in the same way as a duly promulgated regulation. The agencies acknowledged this distinction and signaled that additional rulemaking would follow.
- The 2025 Proposed Rule
On November 20, 2025, the EPA and the USACE published a proposed rule (90 Fed. Reg. 52,498) intended to "fully implement" Sackett and provide greater regulatory certainty for landowners and developers. For the first time, the proposed rule would codify definitions of three key terms from Sackett. "Relatively permanent" would mean waters that are standing or continuously flowing year-round or at least during the "wet season," thereby excluding ephemeral waters that flow only in direct response to precipitation. "Tributary" would mean a body of water with relatively permanent flow, a bed and banks, that connects to a downstream traditional navigable water either directly or through features conveying relatively permanent flow; features lacking such flow would sever upstream jurisdiction. "Continuous surface connection" would require both surface water present at least during the wet season and physical abutment (i.e., touching) of a jurisdictional water.
The proposed rule would also add a new exclusion for groundwater, and modify existing exclusions for waste treatment systems, prior converted cropland, and certain ditches. The public comment period closed on January 5, 2026.
- Post-Sackett Decisions
Amidst the regulatory revolving door, Federal courts applying the Sackett standard in the years since the decision have consistently required a continuous surface water connection between wetlands and jurisdictional waters. For example, in Lewis v. United States, 88 F.4th 1073 (5th Cir. 2023), the Fifth Circuit held that dry fields miles from the nearest relatively permanent water, connected only by ditches and non-relatively permanent tributaries, did not satisfy the continuous surface connection test. The Eleventh Circuit in Glynn Environmental Coalition v. Sea Island Acquisition, 146 F.4th 1080 (11th Cir. 2025), held that a wetland separated from a creek by sections of upland and roads was insufficient to establish a continuous surface connection.
- What Does This Mean for You?
The definition of WOTUS directly affects whether a project may require a federal permit under Section 404 of the CWA for the discharge of dredged or fill material. With the regulatory landscape still in flux, landowners, developers, and businesses should:
- Monitor developments as the proposed 2025 rule proceeds through the rulemaking process.
- Determine which regulatory regime currently applies to their state, as the patchwork of injunctions means different standards may govern in different jurisdictions.
- Consult with legal counsel before undertaking development activities near wetlands or other water features to assess current jurisdictional exposure.
We will continue to closely monitor these developments and provide updates as they become available. If you have any specific questions, please do not hesitate to reach out to your contact at Woods Aitken or a member of our Water/Natural Resources Practice Group. We encourage you to subscribe to our Water Law E-Briefs for the latest news, tips, and updates.