On March 20, 2013, the U.S. Supreme Court held in a 7-1 decision that Clean Water Act permits are not required for stormwater runoff from logging roads. The decision in Decker v. Northwest Environmental Defense Center defers to the Environmental Protection Agency’s long-standing interpretation of its Industrial Stormwater Rule and reverses a Ninth Circuit decision that would have resulted in NPDES permit requirements for countless new sources.

The Court reached its holding without reviewing EPA’s newly amended Industrial Stormwater Rule and without considering one of the principal issues on which the Ninth Circuit based its decision: whether stormwater runoff is a “point source” under the Clean Water Act. The regulatory status quo is thus preserved in this case, with a majority of the Court supporting Auer agency deference. However, one critical aspect of the decision is the prospect, signaled in the concurring and dissenting opinions, that support for Auer deference is waning and agencies' interpretations of their own regulations will be scrutinized more heavily in future cases.