For years, farmers and ranchers have worked their land with a close eye on the weather, volatile markets, farm policy and the many regulations that shape everyday business decisions. Among the most influential, and often most confusing of these rules, is the definition of “waters of the United States” (WOTUS). Over the past decade, frequent regulatory changes and court decisions have left many farmers questioning what WOTUS really means for their operations. From the start of this debate, the American Farm Bureau Federation has been the leading voice across industry sectors, consistently advocating for clear, practical regulations that protect farmers while ensuring environmental stewardship.
The Evolving Definition of WOTUS
Under the Clean Water Act (CWA), the term WOTUS serves as the threshold that determines which water bodies fall under federal jurisdiction. Unfortunately, the statute offers little clarity on where that jurisdictional line should be drawn. Over the years, the Environmental Protection Agency and the U.S. Army Corps of Engineers (the agencies) have exploited this ambiguity, expanding their authority far beyond what Congress intended when drafting the law.
From the mid-1980s onward, the agencies operated under a regulatory definition that broadly interpreted WOTUS to include many waters. This expansive interpretation repeatedly ran up against judicial scrutiny. The Supreme Court’s decisions on the limits of the federal government’s regulatory reach, in cases such as Riverside Bayview Homes, Solid Waste Agency of Northern Cook County, and Rapanos, often created more questions than answers.
For example, the Supreme Court’s 4-1-4 split in Rapanos created conflicting standards for federal jurisdiction. Justice Scalia’s plurality introduced the “relatively permanent waters” test, while Justice Kennedy’s concurrence advanced the “significant nexus” test. With no majority opinion, this fractured guidance left regulators and courts without a clear rule, fueling years of litigation and inconsistent interpretations as successive administrations struggled to define WOTUS.
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