On January 9, 2001 the U.S. Supreme Court (Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers), held that the U.S. Corps of Engineers’ claim of jurisdiction over wholly intrastate seasonally ponded abandoned mining ditches, admittedly not wetlands from a technical standpoint and without any connection to waters of the United States was an invalid expansion of Corps’ jurisdiction under the Clean Water Act. Because the Commerce Clause of the United States Constitution grants Congress the authority to regulate wholly intrastate activities only if they "substantially affect" interstate commerce, the Corps relied on the controversial "Migratory Bird Rule," enacted in 1986, to contend that the abandoned mining ditches were "used as habitat by migratory birds which cross state lines," and therefore could "substantially affect" interstate commerce. Affirming that the Clean Water Act was intended to regulate only navigable waters (including the territorial sea) and
