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Navigable Waters Protection Rule

About Waters of the United States

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Current Implementation of “Waters of the United States”

On October 22, 2019, the Environmental Protection Agency and Department of the Army (the agencies) published a final rule (Step One) to repeal the 2015 Rule defining “waters of the United States” and re-codify the regulatory text that existed prior to the 2015 Rule. The final Step One rule became effective on December 23, 2019. Read the final Step One rule.

The Step One rule will be replaced by the Navigable Waters Protection Rule upon its effective date of June 22, 2020. On April 21, 2020, the EPA and the Department of the Army (Army) published the Navigable Waters Protection Rule to define “waters of the United States” (WOTUS) in the Federal Register. For the first time, the agencies are streamlining the definition so that it:
  • includes four simple categories of jurisdictional waters,
  • provides clear exclusions for many water features that traditionally have not been regulated, and
  • defines terms in the regulatory text that have never been defined before.

Congress, in the Clean Water Act, explicitly directed the Agencies to protect “navigable waters.” The Navigable Waters Protection Rule regulates traditional navigable waters and the core tributary systems that provide perennial or intermittent flow into them. The final rule fulfills Executive Order 13788 and reflects legal precedent set by key Supreme Court cases as well as robust public outreach and engagement, including pre-proposal input and comments received on the proposed rule.  Read the final rule.

If a state, tribe, or an entity has specific questions about a pending jurisdictional determination or permit, please contact a local U.S. Army Corps of Engineers District office or the EPA. 

Current Regulatory Definition of “Waters of the United States” Recodified in the Step One Rule

Until the Navigable Waters Protection Rule takes effect, the Step One rule is in effect. 40 CFR 230.3(s) indicates that 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.

Waters of the United States do not include prior converted cropland. Notwithstanding the determination of an area’s status as prior converted cropland by any other federal agency, for the purposes of the Clean Water Act, the final authority regarding Clean Water Act jurisdiction remains with EPA.

Guidance Documents on the Definition of “Waters of the United States”

Rapanos v. United States and Carabell v. United States

In 2007 and again in 2008, the agencies developed guidance for implementing the above definition of “waters of the United States” under the Clean Water Act following the Rapanos v. United States, and Carabell v. United States Supreme Court decision.

Solid Waste Agency of Northern Cook County (SWANCC) v. United States

In 2001 and again in 2003, the agencies developed guidance to address the above definition of “waters of the United States” under the Clean Water Act following the SWANCC Supreme Court decision.

  • January 2003 Legal Memorandum discussing the scope of the Clean Water Act jurisdiction in light of the SWANCC ruling and related court decisions.
  • January 2001 Legal Memorandum describing which aspects of the regulatory definition of “waters of the United States” are and are not affected by SWANCC. This guidance is superseded by the 2003 guidance.


1989 Memorandum of Agreement - Allocates responsibilities between EPA and the Corps for determining the geographic scope of the Section 404 program and the applicability of exemptions from regulation under Section 404(f).

1979 “Civiletti” Memorandum - U.S. Attorney General opinion on ultimate administrative authority under Section 404 to determine the reach of navigable waters and the meaning of Section 404(f).

Clean Water Act Section 404 and Agriculture - Includes the 1990 Memorandum to the Field and the Memorandum withdrawing the Interpretive Rule.

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Supreme Court Rulings Related to “Waters of the United States”

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2015 Clean Water Rule

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Related Information

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