President Trump’s executive order Restoring the Rule of Law, Federalism, and Economic Growth by Reviewing the "Waters of the United States" Rule calls for the “rescinding or revising” of the Waters of the United States (WOTUS) definitional rule published in the summer of 2015. Many state and local governments objected to the broad nature of these regulations, in particular to the expansive definition of ditches and the ambiguous definition of tributaries.  

The executive order acknowledges that rewriting the WOTUS definitional regulations will require going through the lengthy and complicated process under the Administrative Procedures Act which the 2015 final regulations went through. This process involves proposing a new rule, receiving and responding to (likely thousands) of comments, and issuing a final rule.

The current WOTUS regulations are subject to complicated litigation. In October 2015 the Sixth Circuit issued a temporary stay of the regulations preventing them from going into effect nationally. In February 2016 the Sixth Circuit ruled that it, rather than a federal district court, has jurisdiction to rule on whether the WOTUS rule exceeded the Clean Water Act.

In January 2017 the Supreme Court agreed to review the Sixth Circuit ruling that an appellate court not a district court has jurisdiction to rule on WOTUS. This case, National Association of Manufacturers v. Department of Defense, will not be heard until next fall 2017—meaning the Supreme Court may not issue an opinion in this case until as late as June 2018.    

What will be the fate of all this WOTUS litigation over the current rule in light of the executive order? We don’t know, but the executive order directs the Attorney General to “inform any court of such review and take such measures as he deems appropriate concerning any such litigation pending the completion of further administrative proceedings related to the rule.”

The Attorney General may ask the Sixth Circuit to voluntarily vacate its decision temporarily staying the regulations given that the new administration intends to change them. The Sixth Circuit is more likely to agree to this if none of the parties object. A number of states and environmental groups have intervened in support of the current WOTUS regulations and may object.

If the Sixth Circuit vacates the stay the practical effect is the current regulations would no longer be valid. Vacatur of the Sixth Circuit stay also would likely moot the Supreme Court challenge on jurisdiction. If the Sixth Circuit refuses (or isn’t asked) to vacate the Sixth Circuit decision regarding the stay, the Supreme Court jurisdiction litigation is likely to proceed indefinitely.

Given that defining WOTUS has been so difficult and contentious, almost no matter what new definition is proposed it too will be subject to litigation.

The executive order instructs that Justice Scalia’s decision in Rapanos v. United States be “considered” in defining the term “navigable waters.” Rapanos is a 4-1-4 decision. Justice Scalia wrote the plurality opinion defining this term more narrowly than Justice Kennedy’s solo concurring opinion. The Sixth Circuit considered Justice Kennedy’s opinion controlling. If the new definition of WOTUS relies on Justice Scalia’s opinion—it will almost certainly be challenged on this ground, along with many others.