On May 31, 2016, in a unanimous ruling, the United States Supreme Court held that the Army Corps’ determination as to whether “protected waters,” subject to Clean Water Act regulations, are present on a property is subject to judicial review. See United States Army Corps of Engineers v. Hawkes Co., Inc. No. 15-290 (U.S. May 31, 2016). The ruling enables landowners to challenge approved jurisdictional determinations in federal court, rather than require them to complete the often “arduous, expensive, and long” permitting process required by the Clean Water Act and Army Corps regulations. Chief Justice John Roberts, writing for the Court, reasoned that an approved jurisdictional determination, regarding whether federally-regulated “waters of the United States” or “navigable waters” are present on site, qualifies as a “final agency action” that is subject to judicial review under the Administrative Procedure Act. The dispute in Hawkes Co. was sparked when the Army Corps issued a final, approved jurisdictional determination stating that property owned by the company contained wetlands that were regulated by the Army Corps under Section 404 of the Clean Water Act. The Court rejected the federal government’s argument, finding that the permittee need not wait until after the Army Corps brings an enforcement action to contest the Corps’ determination. The decision enables individuals and companies to more easily challenge the federal government’s ability to regulate development of their property. It is but the latest challenge to the jurisdictional scope of the Clean Water Act.