Waters of the United States (WOTUS)

Federal jurisdiction under the Clean Water Act (CWA) is limited to “Waters of the United States,” or WOTUS for short. The WOTUS definition indicates where the federal government can require permits to protect rivers, wetlands, lakes, estuaries, and other waterbodies from pollution.

The process for determining which waters meet the definition of  WOTUS was relatively stable until 2001. A U.S. Supreme Court decision that year (known as SWANCC) and a subsequent decision in 2006 (known as Rapanos) resulted in inconsistent application of CWA requirements and confusion among federal and state agencies about which waters were covered by the Act. Efforts to clarify the rulings through legislation and rulemakings resulted in a dramatic politicization and polarization of the concept, with clean water interests advocating for the broadest application and some development, industrial, and agricultural interests wanting a very narrow definition.

As the WOTUS definition continues to shift, use this page in tandem with the Clean Water Act Owner’s Manual for the latest updates.

What’s the Current WOTUS Definition?

Last updated 10/12/2022

Currently, the 1986/88 definition is in place:

The term waters of the United States means:

  1. All waters which are currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide;
  2. All interstate waters including interstate wetlands;
  3. All other waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds, the use, degradation or destruction of which could affect interstate or foreign commerce including any such waters: 
    1. Which are or could be used by interstate or foreign travelers for recreational or other purposes; or
    2. (From which fish or shellfish are or could be taken and sold in interstate or foreign commerce; or
    3. Which are used or could be used for industrial purposes by industries in interstate commerce;
  4. All impoundments of waters otherwise defined as waters of the United States under this definition;
  5. Tributaries of waters identified in paragraphs (s)(1) through (4) of this section;
  6. The territorial sea;
  7. Wetlands adjacent to waters (other than waters that are themselves wetlands) identified in paragraphs (s)(1) through (6) of this section; waste treatment systems, including treatment ponds or lagoons designed to meet the requirements of CWA (other than cooling ponds as defined in 40 CFR 423.11(m) which also meet the criteria of this definition) are not waters of the United States.

(40 CFR 230.3(s) at the time)

Check EPA’s “Current Implementation of Waters of the United States” page for the latest and additional context.

State Policy Perspective

For examples of how states are stepping up and clarifying what streams are protected from unpermitted pollution under their own laws or expanding their state jurisdiction to make sure critical headwater streams are protected, visit River Network’s State Policy Hub! It includes a section on Bolstering CWA Protections and features interviews with on-the-ground advocates from North Carolina, as well as state-level policy examples from across the country.