Opinion of the Court
away”).
More recently, the agencies have engaged in a flurry of rulemaking defining “the waters of the United States.” In a 2015 rule, they offered a muscular approach that would subject “the vast majority of the nation’s water features” to a case-by-case jurisdictional analysis.[1] Although the rule listed a few examples of “waters” that were excluded from regulation like “[p]uddles” and “swimming pools,” it categorically covered other waters and wetlands, including any within 1,500 feet of interstate or traditional navigable waters. 80 Fed. Reg. 37116–37117. And it subjected a wider range of other waters, including any within 4,000 feet of indirect tributaries of interstate or traditional navigable waters, to a case-specific determination for significant nexus. Ibid.
The agencies repealed this sweeping rule in 2019. 84 Fed. Reg. 56626. Shortly afterwards, they replaced it with a narrower definition that limited jurisdiction to traditional navigable waters and their tributaries, lakes, and “adjacent” wetlands. 85 Fed. Reg. 22340 (2020). They also narrowed the definition of “[a]djacent,” limiting it to wetlands that “[a]but” covered waters, are flooded by those waters, or are separated from those waters by features like berms or barriers. Ibid. This rule too did not last. After granting the EPA’s voluntary motion to remand, a District Court vacated the rule. See Pascua Yaqui Tribe v. EPA, 557 F. Supp. 3d 949, 957 (D Ariz. 2021).
The agencies recently promulgated yet another rule attempting to define waters of the United States. 88 Fed. Reg. 3004 (2023) (to be codified in 40 CFR §120.2). Under that broader rule, traditional navigable waters, interstate waters, and the territorial seas, as well as their tributaries and adjacent wetlands, are waters of the United States. 88
- ↑ EPA & Dept. of the Army, Economic Analysis of the EPA-Army Clean Water Rule 11 (2015).
