Sometimes the most monumental Supreme Court decisions spring from the most modest facts.

In 2004 Michael and Chantell Sackett bought property near Priest Lake, Idaho and backfilled the lot with dirt in preparation for building a house. A few months later, the Environmental Protection Agency (EPA) notified the Sacketts that their property contained wetlands and ordered the couple to restore the site or face penalties of up to $40,000 a day.

The wetlands at issue are separated by a 30-foot road from an unnamed tributary that feeds into a non-navigable creek that feeds into Priest Lake, a navigable but wholly intrastate water body. The Sacketts challenged the order, claiming that the wetlands are not jurisdictional “waters of the United States” within the meaning of the federal Clean Water Act, 33 U.S.C. §§ 1251-1389 (CWA). Thus began nearly two decades of litigation, culminating in the Supreme Court’s May 25, 2023 decision in Sackett v. EPA, 598 U.S. ___ (2023).

All nine justices agree with the Sacketts that the wetlands on their property are beyond the scope of government’s CWA jurisdiction. But at least four justices sharply disagree with the majority’s opinion limiting the scope of the federal government’s CWA authority over wetlands “to only those wetlands with a continuous surface connection to bodies that are ‘waters of the United States’ in their own right, so that they are indistinguishable from those waters.” Id., 598 U.S. ___, ___ (2023) (slip. op. at 27) (internal punctuation and citations omitted).

In so holding, the majority expressly rejects the “significant nexus” test espoused by Justice Kennedy in his concurring opinion in Rapanos v. United States, 547 U. S. 715 (2006), and embraced ever since in a series of rulemakings and jurisdictional determinations by the EPA and the U.S. Army Corps of Engineers (ACE), the two federal agencies conferred by Congress with authority to oversee federal CWA implementation.

In delivering the opinion of the Court, Justice Alito couches his textual analysis in the long history of water regulation in the United States, tellingly noting that, “For most of this Nation’s history, the regulation of water pollution was left almost entirely to the States and their subdivisions.” Id. at __ (slip op. at 2). The majority’s textual analysis thus places great emphasis on the pre-CWA historical understanding of the plural “waters,” given the statute’s somewhat tautological use of the plural in defining “navigable waters” as “waters of the United States.” This historic understanding, the Court concludes, means that such waters encompass “only those relatively permanent, standing or continuously flowing bodies of water ‘forming geographic[al] features’ that are described in ordinary parlance as ‘streams, oceans, rivers, and lakes.’” Id. at ___ (slip op. at 14) (citations omitted).

The Court next examines state dredge and fill permitting authority under Section 404(g) of the CWA, 33 U.S.C. § 1344(g). That section provides that states may apply to the federal government for permission to issue permits covering “(1) any waters of the United States, (2) except for traditional navigable waters, (3) “including wetlands adjacent thereto.” Id. at ___ (slip op. at 18). Then, in a passage more akin to algebra than jurisprudence, the Court opines:

The provision provides that States may permit discharges into these waters, but it then qualifies that States cannot permit discharges into a subcategory of A: traditional navigable waters (category B). Finally, it states that a third category (category C), consisting of wetlands “adjacent” to traditional navigable waters, is “includ[ed]” within B. Thus, States may permit discharges into A minus B, which includes C. If C (adjacent wetlands) were not part of A (“the waters of the United States”) and therefore subject to regulation under the CWA, there would be no point in excluding them from that category.

Id. at ___ (slip op. at 19). While noting that the word “adjacent” can mean “contiguous” or “near,” the majority nevertheless concludes that “[w]etlands that are separate from traditional navigable waters cannot be considered part of those waters, even if they are located nearby.” Id. at ___-___ (slip op. at 19-20).

From this rather complex calculus, the Court ultimately concludes:

In sum, we hold that the CWA extends to only those wetlands that are as a practical matter indistinguishable from waters of the United States. This requires the party asserting jurisdiction over adjacent wetlands to establish first, that the adjacent body of water constitutes waters of the United States (i.e., a relatively permanent body of water connected to traditional interstate navigable waters); and second, that the wetland has a continuous surface connection with that water, making it difficult to determine where the ‘water’ ends and the ‘wetland’ begins.

Id. at __ (slip op. at 22).

In a concurring opinion (in which Justices Kagan, Sotomayor, and Jackson join), Justice Kavanaugh sharply criticizes the majority opinion, noting that it effectively reads out the plain meaning of “adjacent,” effectively rendering it a synonym for “adjoining,” a term narrower than Congress intended. He goes on to observe that for 45 years, under eight presidential administrations with radically different political views, EPA and ACE have regulated wetlands when separated from “waters of the United States” by “man-made dikes or barriers, natural river berms, beach dunes, or the like,” reflecting a “consistency in interpretation [that] is strong confirmation of the ordinary meaning of adjacent wetlands. Id. at ___, (slip op. at 8) (Kavanaugh, J., concurring).

The distinction between “adjacent” and “adjoining,” Justice Kavanaugh posits, is likely to have significant real world consequences. Id. at ___, (slip op. at 13) (Kavanaugh, J., concurring). Pollutants from wetlands can flow across or under small sections of dry ground (like levees, berms and dunes) to waters of the United States, and the majority’s “continuous surface connection” test may wind up adversely affecting water quality and flood control. Id.

The regulatory community is hailing the Court’s Sackett decision as a victory for industry, certainty, and commonsense. After decades of shifting regulatory definitions and jurisdictional determinations, the Sackett decision is likely to make life easier for property developers who will now be able to determine whether a wetland is jurisdictional simply by looking. It remains to be seen whether water quality and flood control will suffer as a result or whether state or local authorities will fill any purported regulatory void.