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Sackett Decision Guidance from Public Policy & Regulation Section

On August 29, 2023, the US Environmental Protection Agency (EPA) and the US Army Corps of Engineers (USACE) released the pre-published Rule: Revised Definition of ‘Waters of the United States’.  The agencies advised they are intending to have the Rule become effective on the yet-to-be-announced date of publication in the Federal Register to eliminate further delay in implementation. While the language of the rule is known, it remains unknown how the criteria will be applied in the field.  Therefore, Approved Jurisdictional Determinations remain on hold.

The Supreme Court’s opinion on Sackett, released May 25, 2023, referred to the most recent Waters of the U.S. Rule published on January 18, 2023 (January 2023 WOTUS Rule).  Consequently, the agencies stated in the introductory portion of their recent rule that they could simply revise the January 18, 2023, rule to make it comply with the findings of the Supreme Court.  As a result, the ACOE and EPA issue this rule as a “good cause rule” this revision of the Rule, meeting court requirements and no public comment was warranted.

Two of the most important things the rule did are that the rule removes the “Significant Nexus Test.” This test was a result of the Rapanos Supreme Court Case and allowed the EPA and USACE to evaluate waters (tributaries, ponds etc.) and wetlands, either separately or collectively, by whether they had a “material influence on the chemical, physical or biological integrity of waters of the United States”.  Without this test, many wetlands will likely be no longer regulated under the Clean Water Act (CWA) unless they qualify as Adjacent Wetlands.

Secondly, the rule revises the “Adjacent Wetlands” definition to be wetlands adjacent to the territorial seas, interstate waters, waters able to carry interstate commerce and their tributaries are regulated under the CWA. The Supreme Court looked back to the original CWA legislation and deliberations over the legislation and decided that this definition was overly broad and that instead only wetlands “having a continuous surface connection” should be regulated as adjacent.

The consequence of these two changes is substantial. Tributaries can no longer simply have a “significant nexus” to the traditional waters regulated by the CWA. The Supreme Court in Sackett unanimously agreed with the plurality of the Supreme Court in Rapanos that tributaries had to be “relatively permanent, standing or continuously flowing bodies of water”.  The plurality in that earlier case explained that “relatively permanent” waters did “not necessarily exclude streams, rivers or lakes that might dry up in extraordinary circumstances, such as drought” or “seasonal rivers which contain continuous flows during some months of the year but no flow during dry months”.  Consequently, it appears the EPA and USACE will no longer regulate “ephemeral water bodies” that flow or contain water only immediately after rain events and are not receiving groundwater input for at least a season or longer.

Additionally, adjacent wetlands must, per the Sackett decision now have a “continuous surface connection to bodies that qualify as ‘waters of the United States’ in their own right, so that there is no clear demarcation between ‘waters’ and ‘wetlands’.” Wetlands now separated from traditionally regulated waters by berms or other obstructions (that are not themselves illegally placed) will likely no longer be regulated. These wetlands can now be considered “isolated” as they are no longer regulated by the Corps.  So, this revised rule greatly expands the number of isolated wetlands not regulated by the Corps under the CWA. Furthermore, wetlands can no longer be regulated simply because they are interstate in nature (cross a state line) and must now meet the adjacency test. Otherwise, they will not be regulated by the Corps under the CWA.

Implications of the new rule for programs administered through states, such as Section 401 water quality certification, NPDES permits will vary based on the policies and interpretations of each state (Creed et all 2017).

Lastly, as we will be monitoring how this guidance is implemented and applied nationally, additional information will be provided to the membership. This summary was prepared by John Lowenthal and the SWS Public Policy and Regulations Section. Please provide any questions or comments to this summary to, or John directly at


Creed IF, Lane CL, Alexander L, Basu NB, Calhoun A, Cohen MJ, Craft C, D’Amico E, DeKeyser E, Fowler L, Golden HE, Jawitz JW, Kalla P, Kirkman LK, Lang M, Leibowitz SG, Lewis DB, Marton J, McLaughlin DL, Raanan-Kiperwas H, Rains MC, Rains KC, Smith L, Serran JN (2017) Enhancing protections for vulnerable waters. Nature Geoscience 10:809-815

EPA/ACOE Guidance located here:



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