The U.S. Supreme Court recently issued a decision that limits what constitutes “waters of the United States” under the Clean Water Act, but the regulatory whirlpool of uncertainty is expected to swirl until a replacement regulation, now under construction, is finalized.

The court’s opinion in Sackett v. EPA comes five months after the Biden administration finalized the 2023 WOTUS rule extending federal authority over wetlands and other waterbodies, which would complicate and slow down electric infrastructure projects.

“The bottom line is that with fewer jurisdictional waters, fewer federal CWA permits should be required, particularly those for dredging and filling wetlands and other WOTUS under CWA Section 404, which regulates those activities,” said Viktoria Seale, NRECA regulatory affairs director.

“Overall, it’s good news, but there will be continued uncertainty as the regulatory agencies grapple with how to respond to the court decision and ongoing legal action in 27 states, where the 2023 WOTUS rule was sidelined, and the Environmental Protection Agency is interpreting WOTUS consistent with the pre-2015 regulatory regime.”

In the Sackett v. EPA case, a couple sued the federal agency for threatening to levy penalties of over $40,000 a day for construction of a house on their property near Priest Lake, Idaho. EPA contended the Sacketts violated WOTUS provisions protecting the wetlands “because they were near a ditch that fed into a creek, which fed into Priest Lake, a navigable, intrastate lake.”

The court ruled for the property owners and held that the CWA only extends to adjacent wetlands that are “indistinguishable” from a “relatively permanent” jurisdictional water body and have a “continuous surface connection” to that jurisdictional water.

The court rejected the EPA and the U.S. Army Corps of Engineers’ expansive test that had stretched the CWA’s reach to nearly all water features in the United States, permanent or not, and is used throughout the 2023 WOTUS rule.

The rule’s “dual test” approach authorized EPA and the Corps to determine, case-by-case, if certain waters are subject to CWA mandates. It also allowed EPA to regulate tributaries, adjacent wetlands and “additional waters”—intrastate lakes and ponds, streams or wetlands that the agency believed met the test.

“The Supreme Court knocked out the foundation of the 2023 rule by rendering the so-called ‘significant nexus’ test unlawful,” Seale said. “While the agencies have indicated they will interpret WOTUS consistent with the Sackett decision, the rule is technically on the books until there is a new one.”

The Corps and EPA have begun work on regulation to amend the 2023 WOTUS rule and intend to fast-track it rather than proceed through the usual rulemaking process. Michael Connor, assistant secretary of the Army for Civil Works, announced that plan Thursday during a House Transportation and Infrastructure Committee hearing.

In the meantime, Corps districts have paused issuing approved jurisdictional determinations. These determinations were often sought by co-ops when it was unclear if a project required a CWA permit.

“NRECA will continue engaging with the agencies and Congress on the WOTUS rule and keep members informed of any developments,” said Seale.