A consortium of Chicago-area municipalities known as the Solid Waste Agency of Northern Cook County (SWANCC) sought to develop a balefill (landfill for baled nonhazardous solid waste) on a 533-acre site in northern Illinois once used for sand and gravel mining. When mining ceased, excavation trenches and pits filled with water, creating a series of isolated, permanent and seasonal ponds. These waters were not navigable in fact and had no surface connection to traditional navigable waters. During the permit process under § 404 of the Clean Water Act (which regulates the discharge of dredged or fill material into "navigable waters"), the U.S. Army Corps of Engineers initially indicated it lacked jurisdiction. The Corps later asserted jurisdiction under its regulation defining "waters of the United States" to include certain "other waters" (33 C.F.R. § 328.3(a)(3)) and, specifically, under the so-called Migratory Bird Rule, an interpretation announced in a 1986 Federal Register notice that extended jurisdiction to intrastate waters used as habitat by migratory birds that cross state lines. Noting that over 100 species of migratory birds had been observed on the site, the Corps asserted jurisdiction and ultimately denied the § 404 permit on environmental and alternatives grounds. SWANCC sued, arguing that the CWA did not authorize regulation of isolated, nonnavigable, intrastate waters on the basis of migratory bird use and that such an interpretation raised serious constitutional concerns. The district court granted summary judgment to the Corps, and the Seventh Circuit affirmed. The Supreme Court granted certiorari and reversed.
Does the Clean Water Act authorize the Army Corps of Engineers to assert § 404 jurisdiction over isolated, nonnavigable, intrastate waters based solely on their use by migratory birds pursuant to the Migratory Bird Rule?
The Clean Water Act extends § 404 permitting jurisdiction to "navigable waters," defined as "the waters of the United States." While that phrase can reach beyond waters navigable in fact, it does not, absent a clear statement of congressional intent, encompass isolated, nonnavigable, intrastate ponds based solely on ecological connections such as use by migratory birds. Agency interpretations that would significantly alter the federal-state balance in the absence of a clear congressional directive are disfavored, and courts will construe statutes to avoid serious constitutional questions (including those under the Commerce Clause and principles of federalism). See 33 U.S.C. § 1362(7); United States v. Riverside Bayview Homes, Inc., 474 U.S. 121 (1985); Gregory v. Ashcroft, 501 U.S. 452 (1991).
No. The Clean Water Act does not authorize the Corps to regulate isolated, nonnavigable, intrastate waters based solely on their use by migratory birds. The Migratory Bird Rule exceeds the Corps' statutory authority.
The Court, in an opinion by Chief Justice Rehnquist, began with the statutory text: the CWA authorizes regulation of discharges into "navigable waters," defined as "the waters of the United States." Although in Riverside Bayview the Court upheld regulation of wetlands adjacent to navigable waters, that decision turned on the ecological relationship between adjacent wetlands and waters that are or could become navigable. The adjacent-wetlands context provided a plausible nexus to navigable waters consistent with the statute's use of the term "navigable." By contrast, the ponds at issue here were isolated, wholly intrastate waters with no surface connection to navigable waters. The Corps' assertion of jurisdiction rested on the Migratory Bird Rule, an interpretive gloss providing that intrastate waters used as habitat by migratory birds are "waters of the United States" because of their relationship to interstate commerce. The Court rejected this interpretation for two principal reasons. First, as a matter of statutory construction, reading "navigable waters" to include isolated ponds based solely on migratory bird use stretched the term beyond its textual and historical limits, especially given Congress's retention of the word "navigable" and the Act's structure indicating that some limits remain. The Court emphasized that Congress's policy statement in § 101(b) recognizes and preserves the "primary responsibilities and rights" of States in land and water use, counseling against a sweeping construction that would confer federal jurisdiction over any isolated pond. Second, the Court invoked the federalism clear-statement principle and the canon of constitutional avoidance. Extending CWA jurisdiction to all isolated waters based on their use by migratory birds would raise serious constitutional questions under the Commerce Clause and would significantly alter the federal-state balance in traditional areas of state authority, such as land-use regulation. In such circumstances, the Court requires a "clear indication" from Congress that it intended that result. The statute contained no such clear statement. Given these constitutional concerns, the Court declined to defer to the Corps' interpretation under Chevron, noting that deference is inappropriate when an agency interpretation would encroach upon areas of traditional state authority in the absence of a clear congressional directive. The Court therefore construed the CWA not to reach the isolated ponds at issue and invalidated the Migratory Bird Rule as beyond the Corps' statutory authority. Justice Stevens, joined by three Justices, dissented, arguing that the Corps' interpretation was a reasonable construction of an ambiguous statute entitled to Chevron deference and that Congress's Commerce Clause power supported regulation of intrastate waters whose aggregate effects implicate interstate commerce (including via migratory bird habitat). The majority, however, resolved the case on statutory grounds without deciding the constitutional question.
SWANCC is a cornerstone case limiting federal jurisdiction under the Clean Water Act. It rejects the proposition that isolated, nonnavigable, intrastate waters may be regulated solely because of their ecological or economic connections to interstate commerce (here, migratory bird habitat). For environmental and administrative law, it underscores that courts will not extend agency authority into areas of traditional state control absent a clear congressional statement and that constitutional avoidance can constrain otherwise expansive agency interpretations. For constitutional law, SWANCC highlights the Court's sensitivity to federalism in environmental regulation. Doctrinally, SWANCC set the stage for later disputes over the scope of "waters of the United States" in Rapanos v. United States (2006) and, more recently, Sackett v. EPA (2023). It remains essential for understanding the interplay among statutory text, agency deference, and federalism canons in environmental regulation.
SWANCC marks a critical retrenchment in the federal governments authority under the Clean Water Act. By holding that isolated, nonnavigable, intrastate ponds do not fall within the statute based solely on their use by migratory birds, the Court reaffirmed limits implied by the term "navigable" and insisted on a clear congressional statement before federal regulation encroaches on traditional state domains of land and water use.