The U.S. Supreme Court’s decision in Sackett v. EPA on May 25 redefined the approach to determine what is a Water of the United States (WOTUS) under the Clean Water Act (CWA), the critical prerequisite for actions under the CWA. If not, the CWA does not apply. Prior to Sackett, the EPA and the Army Corps of Engineers (Corps) had published a rule, earlier in 2023 (the 2023 Rule), regarding how they would assess the question of what is WOTUS. On Aug. 29, the EPA and the Corps issued a new updated rule to conform to the 2023 Rule in light of Sackett which effectively nullified portions of the 2023 Rule.

The updated rule:

• Eliminates the 2023 Rule’s “Significant Nexus” test;
• Eliminates “interstate wetlands” from CWA’s jurisdiction;
• Changes the 2023 Rule’s conception of “adjacent” which allowed coverage of, for example, wetlands separated from other WOTUS by man-made dikes or barriers, natural river berms, beach dunes, etc. by defining “adjacent” as “having a continuous surface connection.”

However, perhaps the most impactful ruling by the Court is that WOTUS includes tributaries, intrastate lakes, and ponds only if they are “relatively permanent, standing or continuously flowing bodies of water” with a continuous surface connection to jurisdictional waters. Before this change, ephemeral streams, lakes, and ponds could have coverage under the CWA.

The agencies are issuing this updated rule without the need for public comment which is normally required based on their claim that there is sufficient “good cause” because it must be immediately effective and that it merely conforms to the Sackett opinion. They further assert that it does not impose any burdens on any regulated entity. This action will no doubt be challenged administratively and through the courts.

The new rule does not resolve the many uncertainties that exist when an agency applies the new rulein a particular setting. Is a wetland adjacent? Is it relatively permanent? Does it have a continuous connection to a flowing body of water? It is inevitable that there will be a difference of opinion as to any particular water body when viewing that body and its possible connections to other water bodies.

However, the Sackett decision does leave a vacuum that can be filled by the state’s role in regulating non-WOTUS water. A state can define and widen its jurisdiction based on each state’s laws and rules, which could significantly impact an owner dealing with non-WOTUS water. For example, California is taking steps to implement its own dredge and fill permitting programs, the implementation of which is not yet fully known. Also, the impact of such rules on tribal lands remains to be seen.

In the final analysis, while Sackett altered and clarified some questions often arising in a CWA determination, logically it is certain that the issue of what is and what is not WOTUS will of necessity, be determined on a case-by-case basis. As such, it should be expected that there will be differences in decisional outcomes of similarly situated WOTUS in various locations because of the subjective nature of various determinations that have to be made. There will be further differences from state to state. It is likely that we will see agency enforcement and litigation in relation to whether a particular water body is a WOTUS. Instead of viewing Sackett as an answer to key CWA questions, it must be regarded as only supplying a new set of definitions that may change the WOTUS landscape to a degree, subject to a regulator’s view of a particular situation.