The National Sea Grant Law Center


  • EPA and Army Propose New WOTUS Definition

  • December 14th, 2018 — by Terra Bowling — Category: Clean Water Act

  • On Tuesday, the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers issued a proposed rule defining “waters of the United States” (WOTUS). The phrase determines the scope of federal jurisdiction under the Clean Water Act (CWA). Congress enacted the CWA without defining WOTUS, and its meaning has been debated and litigated extensively.

    The proposed rule provides a fairly narrow definition of WOTUS. It outlines six categories of waters that would be federally regulated: traditional navigable waters, tributaries, certain ditches, certain lakes and ponds, and impoundments and adjacent wetlands. The new rule also specifies what would not qualify as WOTUS: features that only contain water during or in response to rainfall; groundwater; many ditches; prior converted cropland; stormwater control features; and waste treatment systems.

    Many developers, farmers, and ranchers herald the proposed rule. They claim the narrower definition will simplify the CWA permitting process by clarifying which waters fall under federal jurisdiction. Environmental groups, on the other hand, say that the new rule will leave smaller tributaries and streams unprotected, ultimately harming the larger waterbodies they feed into.

    The proposed rule would replace a heavily litigated 2015 WOTUS Rule issued by the Obama administration. The 2015 WOTUS Rule has been enjoined in 28 states by several federal court decisions. In February 2017, President Trump issued an executive order asking the EPA and Corps to revise or withdraw the 2015 WOTUS Rule. The agencies issued a stay of that rule. The stay was later overturned by federal district courts in South Carolina and Washington. This means that the 2015 Rule is in effect in the 22 states where injunctions have not been issued. (See Morgan Stringer, How an Obama Administration Regulation Just Became Law in Half the Country, 14:4 SandBar (2018) for more information on those court decisions).

    Public comment on the proposed rule will be open for 60 days after its publication in the Federal Register. The EPA and the Corps will also hold an informational webinar on January 10, 2019. More information is available at:

  • Terra Bowling
    Senior Research Counsel

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