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Navigable Waters Protection Rule

About Waters of the United States

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What are "Waters of the United States"?

The 1972 amendments to the Clean Water Act established federal jurisdiction over “navigable waters,” defined in the Act as the “waters of the United States” (CWA Section 502(7)). Many Clean Water Act programs apply only to “waters of the United States.” The Clean Water Act provides discretion for EPA and the U.S. Department of the Army (Army) to define “waters of the United States” in regulations. To learn more about the regulatory history of “waters of the United States,” see History of “Waters of the United States.”

Current Implementation of “Waters of the United States”

On April 21, 2020, EPA and the Department of the Army (Army) published the Navigable Waters Protection Rule in the Federal Register to finalize a revised definition of “waters of the United States” under the Clean Water Act. The rule became effective on June 22, 2020. The agencies have streamlined 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.

The final rule fulfills Executive Order 13788 and reflects legal precedent set by key Supreme Court cases regarding the limits of federal jurisdiction as well as robust public outreach and engagement, including pre-proposal input and comments received on the proposed rule. Read the final rule.

On June 19, 2020, the District Court for the District of Colorado stayed the effective date of the Rule only in the State of Colorado, and the 2019 Rule remains in effect in Colorado. The NWPR is being implemented by EPA and the Army in all other states and jurisdictions. 

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 EPA. 

“Waters of the United States” is a threshold term in the Clean Water Act and establishes the scope of federal jurisdiction under the Act. Clean Water Act regulatory programs, including Water Quality Standards, TMDLs, and sections 311, 402, and 404 address “navigable waters,” defined in the statute as “the waters of the United States, including the territorial seas.”

The Clean Water Act does not define “waters of the United States”; rather, it provides discretion for EPA and the U.S. Department of the Army to define “waters of the United States” in regulations.

Since the 1970s, EPA and the Department of the Army have defined “waters of the United States” by regulation. In the mid-1980s, both agencies promulgated a definition of “waters of the United States.” Under the 1980s regulations, jurisdictional waters included:

  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 purpose by industries in interstate commerce;
  1. All impoundments of waters otherwise defined as waters of the United States;
  2. Tributaries of waters identified in paragraphs (1)— (4):
  3. The territorial seas; and
  4. Wetlands adjacent to waters (other than waters that are themselves wetlands) identified in paragraphs (1)— (6).

The 1980s regulatory definition of “waters of the United States” provided exclusions for waste treatment systems and prior converted cropland.

Three Supreme Court decisions have addressed the definition of “waters of the United States.” In 1985, in United States v. Riverside Bayview Homes, Inc., the U.S. Supreme Court deferred to the Corps’ assertion of jurisdiction over wetlands actually abutting a traditional navigable water, stating that adjacent wetlands may be regulated as waters of the United States because they are ‘‘inseparably bound up’’ with navigable waters and ‘‘in the majority of cases’’ have ‘‘significant effects on water quality and the aquatic ecosystem’’ in those waters.

In Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (SWANCC) in 2001, the Court rejected a claim of federal jurisdiction over nonnavigable, isolated, intrastate ponds that lack a sufficient connection to traditional navigable waters, noting that the term ‘‘navigable’’ must be given meaning within the context and application of the statute. The Court held that interpreting the statute to extend to nonnavigable, isolated, intrastate ponds that lack a sufficient connection to traditional navigable waters would invoke the outer limits of Congress’ power under the Commerce Clause. In 2001 and again in 2003, the agencies developed guidance to address the definition of “waters of the United States” under the Clean Water Act following the SWANCC  decision.

The Court most recently interpreted the term ‘‘waters of the United States’’ in Rapanos v. United States in 2006. A four-Justice plurality stated that ‘‘waters of the United States’’ ‘‘include[ ] only those relatively permanent, standing or continuously flowing bodies of water ‘forming geographic features’ that are described in ordinary parlance as ‘streams[,] . . . oceans, rivers, [and] lakes,’” and ‘‘wetlands with a continuous surface connection’’ to a ‘‘relatively permanent body of water connected to traditional interstate navigable waters.’’ In a concurring opinion, Justice Kennedy took a different approach, concluding that ‘‘to constitute ‘navigable waters’ under the Act, a water or wetland must possess a ‘significant nexus’ to waters that are or were navigable in fact or that could reasonably be so made.’’ He stated that adjacent wetlands possess the requisite significant nexus if the wetlands ‘‘either alone or in combination with similarly situated lands in the region, significantly affect the chemical, physical, and biological integrity of other covered waters more readily understood as ‘navigable.’’’ Following Rapanos, in 2007 and again in 2008, the agencies developed additional guidance for implementing the “waters of the United States” definition.

The agencies amended their regulations defining “waters of the United States” in 2015. The two federal district courts that reviewed the merits of the 2015 Rule found that the rule suffered from certain errors and issued orders remanding the 2015 Rule back to the agencies. Multiple other federal district courts preliminarily enjoined the 2015 Rule, such that more than half of the states continued to implement the 1980s regulations and not the 2015 Rule. The 2015 Rule was repealed by the 2019 Rule, which reinstated the 1980s regulations, implemented consistent with the U.S. Supreme Court cases and applicable guidance. The following document related to the 2015 Rule is provided for informational purposes only.

The agencies replaced the 2019 Rule with the Navigable Waters Protection Rule in 2020.

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

In the jurisdictions where the Navigable Waters Protection Rule is effective, the materials listed below are inoperative because they are no longer necessary or material.

  • January 2003 Legal Memorandum discussing the scope of the Clean Water Act jurisdiction in light of the SWANCC ruling and related court decisions.

On June 19, 2020, the District Court for the District of Colorado stayed the effective date of the Rule only in the State of Colorado. . As a result of the stay, the 1980s regulations, which the 2019 Rule recodified, remain effective in Colorado. The agencies will use the documents listed above in Colorado to inform implementation of the 2019 Rule for the duration of the stay.

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After finalizing the Navigable Waters Protection Rule, the agencies are developing several memoranda applicable to the definition of “waters of the United States.” Those memoranda can be found here, as they become available.

The memoranda listed below are also related to the definition of “waters of the United States” regardless of the regulations defining “waters of the United States.”

1989 Memorandum of Agreement - Allocates responsibilities between EPA and the Corps for determining the geographic scope of the CWA 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 CWA 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 March 2014 "U.S. Environmental Protection Agency and U.S. Department of the Army Interpretive Rule Regarding the Applicability of Clean Water Act Section 404(f)(l)(A)."

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

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