Waters of the United States (WOTUS) defines the federal jurisdiction of the Clean Water Act (CWA) | Learn More >

Currently, Arizona is operating under the "Revised Definition of 'Waters of the United States'” | Learn More >

The "Revised Definition of 'Waters of the United States'” became effective March 20, 2023, and was revised on Aug. 29, 2023, to incorporate the U.S. Supreme Court decision in the case of Sackett v. Environmental Protection Agency | Learn More >

ADEQ recognizes there is continued debate on what is and is not a WOTUS and supports efforts for additional clarity, data, information and processes to fully evaluate waters. During past EPA efforts to redefine WOTUS, ADEQ has conducted stakeholder outreach and submitted comments to the EPA | View Comments >

For future ADEQ communications and outreach regarding WOTUS, sign up for email notifications. When selecting subscription topics, select Water Quality, proceed to the next page(s), and then select Surface Water Quality where listed | Subscribe >

In 2023, ADEQ implemented a state Surface Water Protection Program (SWPP). Arizona recognized a “local control approach” was needed to ensure consistent protection of our state’s important water resources if protection changes at the federal level | Learn More >