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. This final rule defines the scope of waters federally regulated under the Clean Water Act. The rule became effective on June 22, 2020. 

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)(252 pp, 7 MB)
• Resource and Programmatic Assessment for the Navigable Waters Protection Rule: Definition of "Waters of the United States" (PDF)(103 pp, 2 MB)
• Appendices to the Resource and Programmatic Assessment for the Navigable Waters Protection Rule: Definition of "Waters of the United States" (PDF)(284 pp, 3 MB)