In April 2020, the EPA and the Department of the Army (the agencies) published the Navigable Waters Protection Rule that revised the previously-codified definition of "Waters of the United States” (WOTUS). The agencies initiated a new rulemaking process, "Revised Definition of Waters of the United States,” to restore the regulations in place prior to the 2015 Clean Water Rule, updated to be consistent with relevant Supreme Court decisions in SWANCC (2001) and Rapanos (2006). The agencies also intend to consider further refinements in a second rule that would take into account additional stakeholder engagement and implementation considerations, scientific developments, and environmental justice values. This effort will also be informed by the experience of implementing the pre-2015 rule, the 2015 Clean Water Rule, and the 2020 Navigable Waters Protection Rule.