In Rapanos v. United States, SCOTUS considered whether four Michigan wetlands, which lie near ditches or man-made drains that eventually empty into traditional navigable waters, constitute "waters of the United States" within the meaning of the Clean Water Act, making the "wetlands" fall under the jurisdiction of the Army Corps of Engineers. The Act makes it unlawful to discharge dredged or fill material into "navigable waters" without a permit, and defines "navigable waters" as "the waters of the United States, including the territorial seas." The Corps, which issues permits for the discharge of dredged or fill material into navigable waters, interprets "the waters of the United States" expansively to include not only traditional navigable waters, but also wetlands "adjacent" to such waters and tributaries.
According to the plurality opinion, the Corps has also "asserted jurisdiction over virtually any parcel of land containing a channel or conduit--whether man-made or natural, broad or narrow, permanent or ephemeral--through which rainwater or drainage may occasionally or intermittently flow. On this view, the federally regulated 'waters of the United States' include storm drains, road-side ditches, ripples of sand in the desert that may contain water once a year, and lands that are covered by floodwaters once every 100 years."
This case concerned Rapanos' cornfield, which included 54 acres of land with sometimes-saturated soil conditions. The nearest body of navigable water was 11 to 20 miles away. Regulators informed Mr. Rapanos that his fields were "waters of the United States," that could not be filled without a permit. Twelve years of criminal and civil litigation ensued.
Justice Scalia, writing for a the plurality, rejected the government's broad interpretation of "waters of the United States." Using the canons of statutory construction and giving Chevron difference to the Corps' broad interpretation, the Scalia held that the Act's use of the traditional phrase "navigable waters" confirms that it confers jurisdiction only over relatively permanent bodies of water--not ditches and cornfields. The government expansive interpretation also implicated federalism concerns, and Scalia noted that the result would be a "significant impingement of the States' traditional and primary power over land and water use."
The result was that SCOTUS remanded the case "to determine if these wetlands are covered 'waters of the United States,' and because of the paucity of the record in both of these cases, the lower courts should determine, in the first instance, whether the ditches or drains near each wetland are 'waters' in the ordinary sense of containing a relatively permanent flow."
Because there was only a plurality opinion, uncertainty has been injected into the law. This one could be a mess for the lower courts to sort out.