On December 30, 2022, the United States Environmental Protection Agency (USEPA) released a new rule to redefine “waters of the United States” (WOTUS), which are federally protected under the Clean Water Act of 1972. At this time, the 2022 WOTUS definition has not been published in the Federal Register. The rule will go into effect 60 days after publication.


Various definitions of WOTUS have in been use since the issuance of the Clean Water Act (CWA). In 2015, the USEPA adopted the Clean Water Rule, which attempted to provide a stable definition for WOTUS and expand the types of waters and wetlands regulated under the CWA. The Clean Water Rule notably adopted the significant nexus standard, which extended CWA protection to wetlands that “significantly affect the chemical, physical, or biological integrity” of a recognized WOTUS. Prior to the 2015 Clean Water Rule, wetlands were typically only protected under the CWA if they were directly adjacent/hydrologically connected to a WOTUS. Various lawsuits prevented the Clean Water Rule from going into effect in half the states.

In 2020, the WOTUS definition was changed under the Navigable Waters Protection Act under the Trump Administration. This rule limited jurisdictional WOTUS to four categories: territorial seas and traditional navigable waters; perennial and intermittent tributaries of such waters; lakes, ponds, and impoundments that share a surface water connection with a jurisdictional WOTUS; and wetlands adjacent to jurisdictional WOTUS. The Navigable Waters Protection Act of 2020 notably did not include ephemeral watercourses and the significant nexus standard. The rule was ultimately overturned by a judge in 2021.

2022 WOTUS Definition    

 The 2022 WOTUS definition is based on the pre-2015 regulations, while also incorporating the significant nexus and relatively permanent standards (defined below). Five categories of waters are now protected and defined by the CWA: 

  1. Traditional navigable waters, which are waters that are, have been, or could be used for interstate or foreign commerce. This definition includes all waters subject to tides, territorial seas, and interstate waters and wetlands (collectively “traditional navigable waters”)
  2. Impoundments of WOTUS (collectively “impoundments”)
  3. Tributaries to traditional navigable waters (1) and impoundments of WOTUS (2). This definition also includes waters that are continuously flowing bodies of water or are relatively permanent, i.e. waters that flow year-round or have continuous flow seasonally (typically at least three months) (collectively “tributaries”)
  4. Wetlands adjacent to traditional navigable waters (1), impoundments (2), and tributaries (3) (collectively “adjacent wetlands”). Unlike the previous WOTUS, the 2022 definition includes the significant nexus standard.
  5. Interstate lakes and ponds, streams, or wetlands that do not fall into the above categories but are relatively permanent or meet the significant nexus standard (collectively “interstate jurisdictional waters”)

Exceptions to the 2022 WOTUS Definition

Similar to previous definitions of WOTUS, various exceptions to the above categories are described in the 2022 WOTUS rule. Significant exclusions include the following:

  • Prior converted cropland, which is defined as “any area that was drained or otherwise manipulated to make production of agriculture possible prior to December 23, 1985.” An area is no longer defined as prior converted cropland once the area is not used for agricultural purposes.
  • Wastewater treatment systems for other CWA requirements
  • Ditches that were excavated in uplands or do not have relatively permanent flow
  • Areas that are artificially irrigated and would revert to an upland without continued irrigation
  • Depressions created in uplands related to construction activities (e.g., borrow pits, excavation areas)
  • Swales and erosional features with a minimal and infrequent (less than three months a year) flow.

What's Next? 

Verdantas staff will continue to monitor developments related the 2022 WOTUS rule, including U.S. Army Corps of Engineers guidance and the national and district level, and clarification on the application of terms such as “relatively permanent”.

To learn how 2022 WOTUS Rule may affect your project, please contact us to speak with one of our Professional Wetland Scientists or permitting specialists. Additional information about the 2022 WOTUS rule can be found at Revising the Definition of "Waters of the United States" | US EPA.