The Navigable Waters Protection Rule - Supporting Documents

The final "Revised Definition of 'Waters of the United States'" rule was published in the Federal Register on January 18, 2023, and took effect on March 20, 2023. The Rule is operative in all jurisdictions of the United States except Idaho and Texas. The agencies developed this rule with consideration of the relevant provisions of the Clean Water Act and the statute as a whole, relevant Supreme Court case law, and the agencies’ technical expertise after more than 45 years of implementing the longstanding pre-2015 “waters of the United States” framework. This rule also considers the best available science and extensive public comment to establish a definition of “waters of the United States” that supports public health, environmental protection, agricultural activity, and economic growth. More information about the rule is available here. Please visit the Rule Status page for additional information about the status of the rule and litigation.

On April 21, 2020, the U.S. Environmental Protection Agency (EPA) and the Department of the Army (Army) published the Navigable Waters Protection Rule in the Federal Register to provide a revised definition of “Waters of the United States” under the Clean Water Act. The 2020 NWPR became effective on June 22, 2020. The 2020 NWPR was vacated by two district courts and replaced in the Code of Federal Regulations by the 2023 rule. The 2020 NWPR is not in effect, and the materials below are provided for informational purposes.

The agencies developed both an Economic Analysis and a Resource and Programmatic Assessment as supporting documents to the final rule. The Economic Analysis (EA) assesses the potential impacts of the revised definition of “waters of the United States” based on the potential effects to CWA programs that rely on the definition of “waters of the United States.” The Resource and Programmatic Assessment outlines the agencies’ assessment of the potential effects of the revised definition on CWA programs and certain programs addressing aquatic resource quality under other federal statutes. The Resource and Programmatic Assessment also provides snapshots of the applicable regulatory and legislative frameworks in place by states and tribes. The two documents together present a comprehensive assessment of this rule’s potential impacts.

Additional supporting documents for the rule can be found here in the docket.

• Economic Analysis for the Navigable Waters Protection Rule: Definition of "Waters of the United States" (pdf) (6.75 MB)
• Resource and Programmatic Assessment for the Navigable Waters Protection Rule: Definition of "Waters of the United States" (pdf) (1.72 MB)
• Appendices to the Resource and Programmatic Assessment for the Navigable Waters Protection Rule: Definition of "Waters of the United States" (pdf) (2.85 MB)