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September/October 2023

Supreme Court review

John R Jacus


  • A summary of selected environmental, energy, and natural resources cases decided by the Supreme Court during its October 2022 term.
  • Sackett v. Environmental Protection Agency has broad implications for the scope of the federal government’s jurisdiction under the Clean Water Act.
  • Arizona v. Navajo Nation held that the 1868 peace treaty between the United States and the Navajo Nation establishing the Navajo Reservation does not obligate the United States to take affirmative steps to secure water needed by tribal members on the reservation.
Supreme Court review

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This edition of Trends’ Supreme Court review provides a summary of selected environmental, energy, and natural resources cases decided by the United States Supreme Court (Court) during its October 2022 Term. The impact of the two decisions summarized here is quite significant, with broad implications for the scope of the federal government’s jurisdiction under the Clean Water Act and its trust obligations under historic tribal treaties concerning water resources available to tribal members living on the reservation.

Clean Water Act, Waters of the United States (WOTUS)

Sackett v. Environmental Protection Agency, 143 S. Ct. 1322 (2023)

The Court held that the Clean Water Act’s (CWA) use of “waters” in section 1362(7) refers only to streams, oceans, rivers, and lakes, and extends only to wetlands that are indistinguishable from those bodies of water due to a continuous surface connection. In so doing, the Court reversed the decision of the U.S. Court of Appeals for the Ninth Circuit that upheld EPA’s compliance order concluding that Petitioners Michael and Chantell Sackett had illegally dumped soil and gravel into “waters of the United States” to construct a home on their lot some 300 feet from the banks of Priest Lake, Idaho (an intrastate navigable lake), after 15 years of litigation. The Court observed that the uncertain meaning of “the waters of the United States” (WOTUS) has sparked decades of agency action and litigation, and that resolving the Act’s applicability to wetlands required reviewing the history surrounding judicial interpretation of that phrase. That review resulted in the Court rejecting on multiple grounds EPA’s guidance in place at the time providing that “adjacent wetlands are covered by the [CWA] if they ‘possess a significant nexus to’ traditional navigable waters” and that wetlands are “adjacent” when they are “neighboring” to covered waters. The Ninth Circuit’s decision upholding EPA’s application of its “significant nexus” guidance to determine that the wetlands on the Sacketts’ property were federally jurisdictional was reversed and remanded.

Writing for the majority, Justice Alito began the contentious and difficult task of defining WOTUS by reviewing the decades of agency action and litigation the phrase has sparked. In revisiting the Court’s decision in United States v. Riverside Bayview Homes, Inc., 474 U.S. 121 (1985), which first construed the meaning of WOTUS, the Court noted that it had expressed concern at that time that wetlands seemed to fall outside “traditional notions of ‘waters.” The Court also took note of its rejection of the “migratory bird rule” developed by EPA and the Army Corps of Engineers (Corps) in Solid Waste Agency of Northern Cook Cty. v. Army Corps of Engineers, 531 U. S. 159 (2001) (SWANCC), concerning CWA jurisdiction asserted over isolated ponds in former quarries, holding that the CWA does not “exten[d] to ponds that are not adjacent to open water.” Finally, the Court took note of EPA’s and the Corps’ decision to exercise CWA jurisdiction by employing open-ended factors to make wetland and WOTUS determinations on a case-by-case basis, resulting in expansive body of interpretations covering hundreds of millions of acres of wetlands and “virtually any parcel of land containing a channel or conduit . . . through which rainwater or drainage may occasionally or intermittently flow.” Rapanos v. United States, 547 U. S. 715, 722 (2006) (plurality opinion).

The Court then took stock of where things stood concerning the jurisdictional scope of WOTUS, observing that EPA and the Corps maintain that the significant-nexus test articulated in the concurring opinion of Justice Kennedy in Rapanos has been and remains sufficient to establish jurisdiction over “adjacent” wetlands, but that by EPA’s own admission, “almost all waters and wetlands” are potentially susceptible to regulation under that test. 143 S. Ct. at 1335 (citing 80 Fed. Reg. 37056). The Court was clearly troubled by this state of affairs given that “the CWA can sweep broadly enough to criminalize mundane activities like moving dirt, [so] this unchecked definition of ‘the waters of the United States’ means that a staggering array of landowners are at risk of criminal prosecution or onerous civil penalties.” Id.

In turning to the CWA’s text, the Court concluded that the plurality opinion of four justices in Rapanos was correct: the CWA’s use of “waters” encompasses “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.’” 547 U. S. at 739. This conclusion was based on a textual and ordinary meaning analysis of the term “waters” and the fact that waters of the United States defines “navigable waters.” Thus, the use of “navigable” signals that the definition principally refers to bodies of navigable water like rivers, lakes, and oceans. 143 S. Ct. at 1337 (citing Rapanos, 547 U. S. at 734 (plurality opinion)).

Finally, in addressing what wetlands the CWA regulates, the Court sought to “harmonize the reference to adjacent wetlands in §1344(g)(1) with ‘the waters of the United States,’ §1362(7), which is the actual term we are tasked with interpreting.” 143 S. Ct. at 1339. It did so by observing that certain wetlands must qualify as WOTUS in their own right because they are indistinguishably part of a body of water that itself constitutes “waters” under the CWA, and further reasoning that this understanding is consistent with §1344(g)(1)’s use of “adjacent,” meaning either “contiguous” or “near.” The Court then concluded that the plurality opinion in Rapanos correctly determined that that “waters” may fairly be read to include only those wetlands that are “as a practical matter indistinguishable from waters of the United States,” such that it is “difficult to determine where the ‘water’ ends and the ‘wetland’ begins,” but also acknowledging that temporary interruptions in surface connection may sometimes occur because of phenomena like low tides or dry spells. Id. at 1340.

The Court rejected EPA’s assertions that the term “waters” is “naturally read to encompass wetlands” because the “presence of water is ‘universally regarded as the most basic feature of wetlands,’” noting that this argument is “tough to square with SWANCC, which held that the Act does not cover isolated ponds, see 531 U. S., at 171, or Riverside Bayview, which would have had no need to focus so extensively on the adjacency of wetlands to covered waters if the EPA’s reading were correct, see 474 U.S. at 131–35 &n.8. The Court also rejected EPA’s textual analysis and ratification theory that Congress implicitly ratified its interpretation of “adjacent” wetlands when it adopted CWA section 1344(g)(1) resulting in WOTUS covering any wetlands that are “bordering, contiguous, or neighboring” to covered waters, effectively transplanting the term “adjacent” as used in the Corps’ earliest regulations into that provision. 143 S. Ct. at 1341–44. The Court thus rejected the EPA’s guidance establishing the “significant nexus” test that stemmed from Justice Kennedy’s concurring opinion. 143 S. Ct. at 1341.

In an opinion written by Justice Kavanaugh, four justices joined only in the result of the majority’s decision but criticized the majority for narrowing the Act’s coverage of wetlands to omit many wetlands that EPA and the Corps have long regulated. The four justices also argued that the Court’s decision will lead to the kind of uncertainty that the majority itself had criticized. 143 S. Ct. at 1362–69.

Justice Thomas joined the Court’s opinion in full but wrote separately to opine that two additional waters claimed by EPA and the Corps as WOTUS were not in fact jurisdictional: the “nonnavigable roadside ditch across the street from the Sacketts’ property” and Priest Lake, which “is purely intrastate” and thus not navigable under the expanded Daniel Ball test. 143 S. Ct. at 1357. The majority did not question the agencies’ designation of Priest Lake as a “traditional interstate navigable water” or the roadside ditch as a “tributary.”

The Court did not directly repeal or remand the most recent rule defining “waters of the United States” (88 Fed. Reg. 3004 (Jan. 18, 2023)), but it did criticize that portion of the rule that relies on the so-called “significant nexus” test as a basis for jurisdiction and ultimately rejected that test. 143 S. Ct. at 1334–35, 1341 (“For reasons already explained, [the significant nexus test] is inconsistent with the text and structure of the CWA.”). Following the Court’s decision in Sackett, the agencies ceased relying on the “significant nexus” test and began promulgating a replacement rule. See Envtl. Prot. Agency, Waters of the United States (

The Court in Sackett thus substantially narrowed the scope of waters and wetlands subject to federal jurisdiction of the Clean Water Act. 

Water Resources, Tribal Treaty Rights

Arizona v. Navajo Nation, 143 S. Ct. 1804 (2023)

A 5–4 majority of the Court held that the 1868 peace treaty between the United States and the Navajo Nation establishing the Navajo Reservation does not obligate the United States to take affirmative steps to secure water needed by tribal members on the reservation. The decision reversed an opinion of the U.S. Circuit Court of Appeals for the Ninth Circuit that held the United States does have such a duty under the treaty.

The Court began by reviewing the history and text of the two treaties between the Navajo Nation and the United States and its jurisprudence on federal reserved water rights under the Winters doctrine, whereby the federal government reserves water only “to the extent needed to accomplish the purpose of the reservation.” Winters v. United States, 207 U. S. 564, 576–77 (1908); see also Cappaert v. United States, 426 U. S. 128, 138–39, 143 (1976). The Court also took note of the scarcity of water in the western United States and prior actions of the federal government to secure hundreds of thousands of acre-feet of water for the Navajo Nation and billions of dollars for water infrastructure on the Navajo Reservation. Those efforts notwithstanding, the Navajo Nation asserted the United States had not fully satisfied its obligations under the 1868 treaty, and the Navajo Nation sued the U.S. Department of Interior, the Bureau of Indian Affairs, and other federal parties on a breach of trust claim arising out of the 1868 treaty asserting that the United States must take affirmative steps to secure water for the Tribe. The U.S. District Court for the District of Arizona dismissed the Tribe’s complaint, holding that the 1868 treaty did not impose a duty on the United States to take affirmative steps to secure water for the Tribe, but on appeal the Ninth Circuit reversed, holding that the treaty does impose such an affirmative duty.

The Court began its analysis by noting that when the United States establishes a tribal reservation, the reservation generally includes the land, the minerals below and the timber on it, and the right to use needed water on that land. The Court observed that the Navajo Nation has been able to access that reserved water on the reservation, but now the Tribe asserts the United States must do more to assess the Tribe’s water needs and develop a plan to secure water for the Tribe. Because the Tribe asserts a breach-of-trust claim, the Court noted the Tribe must establish that the text of the 1868 treaty imposed such duties upon the United States. This necessary requirement flows from the principle that the federal government owes judicially enforceable duties to a tribe “only to the extent it expressly accepts those responsibilities.” United States v. Jicarilla Apache Nation, 564 U.S. 162, 177 (2011).

The Court found the Tribe’s view of the treaty imposing an affirmative duty on the United States to be incorrect, noting that while the treaty imposed several specific duties on the United States, including constructing specific buildings, providing teachers for Navajo schools, and providing articles of clothing and other goods, the treaty said nothing about an affirmative duty to secure water. And as the Court has previously stated, “Indian treaties cannot be rewritten or expanded beyond their clear terms.” Choctaw Nation v. United States, 318 U. S. 423, 432 (1943). The Court also noted that it would be anomalous to have such an affirmative duty with respect to water, but not for land, on the reservation. The Court then observed that while the United States has a general trust relationship with tribes, it is a sovereign and not a private trustee, so Congress may style its relations with the tribes as a trust without assuming all the fiduciary duties of a private trustee. Jicarilla, 564 U. S., at 176. Finally, the Court acknowledged that Congress and the president could and did enact legislation to address the water needs of the Navajo Nation, but that it is not the judiciary’s role to update a 155-year-old treaty. Other arguments by the Tribe regarding the treaty’s establishment of a “permanent home” and provision of “seeds and agricultural implements,” and the United States’ control over federal reserved water rights evidenced in other litigation, among others, were all rejected.

Justice Gorsuch authored a dissenting opinion that asserted that the Tribe was simply asking the United States to account for the federal reserved water rights it holds on the Navajo Nation’s behalf and, if they have been misappropriated, to formulate a plan to stop misappropriating them. He and three other justices would have affirmed the Ninth Circuit’s decision.