WOTUS Whack-a-Mole: What Definition Applies This Week?


You can be forgiven if you aren’t sure how jurisdictional waters are currently defined in the United States. Since 2015, the definition of Waters of the United States, or WOTUS, has changed more often than a college freshman changes his sheets. The latest shift comes courtesy of the United States District Court for the District of Arizona, which issued an Order on August 30, 2021 vacating the Trump-era Navigable Waters Protection Rule (NWPR).  The 2020 Trump Rule was already doomed to a relatively slow death by the Biden administrations stated intention to repeal and reissue a new definition, but the federal order—if it survives appeal—puts an immediate end to the NWPR and speeds the long process the EPA and the Corps face in putting out a new WOTUS definition. 

A brief recap of how we got here is in order. The Clean Water Act (CWA), passed in 1972, does not define WOTUS, so from passage of the statute until 2001, agency interpretation of what WOTUS meant was set out by regulation and remained largely unchanged. In 2001, the U.S. Supreme Court interpreted the phrase in Solid Waste Agency of Northern Cook County v. United States Army Corps of Engineers and narrowed the definition to exclude intrastate waters used as habitat for migratory birds. 531 U.S. 159 (2001). The term was further explored (not to say clarified) in Rapanos v. United States, where the Supreme Court issued a 4-1-4 plurality opinion attempting to capture what water bodies are properly regulated under the CWA. 547 U.S. 715 (2006). Notably, it was Justice Kennedy’s standalone concurrence in Rapanos that defined WOTUS practice for the next decade. Kennedy opined that those waters with a “significant nexus” to traditionally navigable waters must necessarily fall within the jurisdiction of the CWA, regardless of whether they are relatively permanent or bear a surface connection with adjacent jurisdictional waters. 

The “significant nexus” test predominated jurisdictional determinations until 2015, when President Obama’s administration adopted the “Clean Water Rule,” significantly expanding the regulatory definition of WOTUS. The Clean Water Rule was immediately challenged by a multitude of litigants, resulting in a number of federal court decisions that stayed the application of the rule in a number of jurisdictions, effectively creating a patchwork of applicable WOTUS definitions that varied based on geography. The Trump administration issued a repeal rule in 2019, which took the WOTUS definition back to pre-2015 regulations (and the Rapanos “significant nexus” standard), and then followed the repeal with the issuance of the NWPR in 2020. The NWPR attempted to codify not the Kennedy opinion from Rapanos, but the narrower plurality opinion with which Kennedy joined in the judgment. Among other changes in the law, the NWPR purported to categorically exclude from CWA jurisdiction ephemeral streams and features, regardless of whether they had a “significant nexus” with traditionally navigable waters. The NWPR was challenged in courts as well. 

Shortly after his election, President Biden issued an Executive Order requiring federal agencies (including EPA and the Corps) to “immediately review and, as appropriate and consistent with applicable law, take action to address the promulgation of Federal regulations” consistent with the new administration’s policy objectives. These objectives expressly included “to listen to the science; to improve public health and protect our environment; [and] to ensure access to clean air and water[.]” Ex. Order 13,990 (January 20, 2021). EPA and the Corps provided public notice of their intent to repeal the NWPR in keeping with this Executive Order, and sought a voluntary remand in the court battles challenging the 2020 rule. Notably, the agencies did not seek to have the NWPR vacated while working to promulgate new regulations. In the Arizona District Court case Pasqua Yaqui Tribe, et al., v. U.S. EPA however, the judge granted the plaintiffs’ request to toss the rule while granting the remand, finding that remanding the rule without vacatur would create serious environmental harm. The judge noted specifically that in New Mexico and Arizona, “nearly every one of over 1,500 streams assessed under the NWPR were found to be non-jurisdictional—a significant shift from the status of streams under both the Clean Water Rule and the pre-2015 regulatory regime.” 

While the Pasqui Yaqui Tribe Order is likely to be appealed to the 9th Circuit, on its face it has the immediate effect of doing what EPA and the Corps would likely need a year or more to accomplish–effectively repealing the NWPR and putting the U.S. back under the pre-2015 definition of WOTUS. While the regulatory uncertainty resulting from the vacatur will be unpopular in many circles, there is at least some familiarity with the pre-2015 definition to which we keep returning. Moreover, the net effect of the Arizona Order is more one of timing rather than substance. A repeal of the NWPR would almost certainly have put WOTUS back into the pre-2015 regime for at least some period of time until the Biden administration could promulgate a new definition. And it’s a foregone conclusion that whatever that new definition looks like, it will face legal challenges of its own, so we may again be experiencing a “significant nexus” with the old WOTUS definition for some time to come.

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