30 December 2022- 2022 Definition of Waters of the U.S. Rule  

On Friday 30 December 2022 the U.S. Environmental Protection Agency and Department of the Army (“the agencies”) announced a final rule to define “waters of the United States” that is founded on the familiar framework of the pre-2015 regulations and provides additional clarity. This rule has been carefully drafted to establish a durable definition that prioritizes implementation, protects vital water resources, and will withstand the test of time.

This action follows through on a regulatory process announced in the summer of 2021 and would not have been possible without the sustained effort from the agencies’ HQ staff and significant regional support.


The agencies developed this rule with considerations for the relevant provisions of the Clean Water Act and the statute as a whole, relevant Supreme Court case law, and the agencies’ technical expertise after more than 45 years of implementing the longstanding pre-2015 “waters of the United States” framework. The final rule also considers the best available science and extensive public comment to establish a durable definition of “waters of the United States” that supports public health, environmental protection, agricultural activity, and economic growth.

A pre-publication version of the final rule, as well as supporting documents such as the economic analysis, technical support document, and fact sheets, are available on EPA’s website at

The agencies carefully reviewed their implementation process and prepared additional implementation materials to support this final rule. These documents are also available on the EPA website and will be discussed with Regional staff on the recurring jurisdiction workgroup calls.  Documents include: