Impacts of Revised Definition of ‘Waters of the United States’ 

The U.S. Environmental Protection Agency and Department of the Army recently released the Revised Definition of ‘Waters of the United States’ (WOTUS) rule (note: the definition begins on page 139). This rule establishes the grounds for determining if a water body is regulated under the federal Clean Water Act, and will take effect March 20, 2023.   

The final rule generally restores long-standing categories which previously defined WOTUS, and now establishes case-specific limitations on regulating a waterbody based on either the “relatively permanent standard” or the “significant nexus standard” for certain categories of waters.  

Of interest to townships, the agencies deleted the broad set of “other waters” that could be interpreted as WOTUS. In removing this section and establishing requirements to meet the relatively permanent or significant nexus standard, fewer waters will be subject to the Clean Water Act under this rule.   

The rule also excludes several categories of waters from the WOTUS definition, notably: ditches (including roadside ditches) excavated wholly in and draining only dry land that do not carry a relatively permanent flow of water; waste treatment systems designed to meet Clean Water Act requirements; prior converted cropland designated by the Secretary of Agriculture; and certain types of water-filled depressions created for the purpose of obtaining fill, sand, or gravel.   

The National Association of Towns and Townships issued a brief on the new rule, including an overview and potential impacts. NATaT submitted comments on the draft rule in 2022. Legal challenges are expected, and the U.S. Supreme Court will likely issue an opinion in 2023 in Sackett v. EPA, a long-running dispute regarding whether certain wetlands are subject to protection under the Clean Water Act. For more information, technical support documents, and fact sheets, please visit the EPA website.