Riverside Bayview Homes, Inc. owned approximately 80 acres of low-lying, marshy land in Macomb County, Michigan, near the mouth of Black Creek, a tributary that flows into Lake St. Clair, an interstate navigable water. In the mid-1970s, the company began placing fill material on portions of the property to prepare it for residential development, without first obtaining a Clean Water Act § 404 permit from the U.S. Army Corps of Engineers. The Corps asserted jurisdiction on the ground that the property constituted wetlands "adjacent" to navigable waters and therefore qualified as "waters of the United States" under the Corps' regulations. After Riverside Bayview declined to apply for a permit and continued filling activities, the United States sought injunctive relief and civil penalties. The district court found that the property was wetlands hydrologically connected to and bordering on navigable waters and enjoined further filling without a permit. The Sixth Circuit reversed, holding that the Corps lacked authority to regulate wetlands unless they were actually navigable or covered by open water. The Supreme Court granted certiorari.
Does the Clean Water Act permit the Army Corps of Engineers to require a § 404 permit for the discharge of fill material into wetlands that are adjacent to navigable waters, by interpreting "waters of the United States" to include such adjacent wetlands?
Under the Clean Water Act, "navigable waters" are defined as "the waters of the United States" (33 U.S.C. § 1362(7)). Where statutory language is ambiguous and the agency charged with implementation adopts a reasonable interpretation consistent with the statute's text, purposes, and legislative history, courts defer to that interpretation. The Corps' regulations defining "waters of the United States" to include wetlands adjacent to navigable waters—characterized by saturation or inundation supporting hydrophytic vegetation—are a permissible construction of the statute, and activities discharging dredged or fill material into such wetlands require a § 404 permit (33 U.S.C. § 1344; then-33 C.F.R. § 323.2).
Yes. The Clean Water Act authorizes the Corps to regulate discharges of fill into wetlands adjacent to navigable waters by requiring § 404 permits; the Corps' interpretation of "waters of the United States" to include adjacent wetlands is reasonable and entitled to deference.
The Court began by recognizing that the CWA's definition of "navigable waters" as "the waters of the United States" is broader than traditional notions of navigability. Congress chose expansive language to effectuate the Act's objective to restore and maintain the chemical, physical, and biological integrity of the Nation's waters. Because the term "waters" is ambiguous as to the inclusion of adjacent wetlands, the Court examined whether the Corps' interpretation was reasonable. First, the ecological relationship between adjacent wetlands and open waters supports the Corps' approach. Adjacent wetlands are "inseparably bound up" with the waters they border: they filter pollutants, reduce flooding, and provide habitat, thereby directly affecting the quality and integrity of navigable waters. Given this functional interdependence, the Corps reasonably concluded that regulating discharges into adjacent wetlands furthers the Act's core purposes. Second, the Court found that the Corps' scientific judgments and technical expertise warranted deference. Drawing lines in hydrologically complex systems is difficult; adjacency provides a workable, administrable criterion that aligns with the statute's goals. Requiring permits for fill in adjacent wetlands is thus a rational means to prevent degradation of downstream navigable waters. Third, the Court rejected arguments that the Corps' jurisdiction must be confined to areas of open water or constantly inundated lands. The statutory term "waters" need not be limited to surface water bodies, especially in light of Congress's broad definition and the Act's protective aims. Nor did the Court accept due process or takings concerns as a basis to narrow the statute: the permitting scheme is flexible, case-by-case, and includes opportunities for variances and mitigation; any takings claim would be better addressed if and when a permit is denied and the regulatory effect is clear. Finally, legislative history and the structure of the CWA—including § 404's focus on dredged and fill material—support the Corps' comprehensive approach to wetlands closely associated with navigable waters. The Court therefore reversed the Sixth Circuit and upheld the Corps' jurisdiction over adjacent wetlands.
Riverside Bayview is a cornerstone of wetlands regulation and administrative deference. Substantively, it validated the federal government's authority to require permits for filling wetlands adjacent to navigable waters, anchoring decades of wetlands protection under the CWA. Doctrinally, it reflects Chevron-style deference to an agency's reasonable interpretation of ambiguous statutory terms, particularly on technical environmental questions. The decision provided the baseline for later Supreme Court cases that refined the scope of "waters of the United States." In Solid Waste Agency of Northern Cook County (SWANCC) (2001), the Court curtailed federal jurisdiction over isolated, non-adjacent waters. In Rapanos v. United States (2006), a fractured Court further narrowed coverage, debating the significance of hydrological connections; and in more recent cases, including Sackett v. EPA (2023), the Court imposed additional constraints on what counts as jurisdictional wetlands. For law students, Riverside Bayview offers enduring lessons on statutory purpose, ecological reasoning, and agency deference, even as the precise boundaries of federal wetlands jurisdiction continue to evolve.
United States v. Riverside Bayview Homes established that wetlands adjacent to navigable waters fall within the ambit of the Clean Water Act's permitting regime. By affirming the Corps' scientific and regulatory judgment, the Court tied statutory interpretation to ecological reality, ensuring that the Act's remedial purpose—preserving the integrity of the Nation's waters—cannot be defeated by artificial distinctions between open water and intimately connected wetlands.