IFAI Analyzes Changes to WOTUS

FAYETTEVILLE, ARK. – On Sept. 9, the Environmental Protection Agency (EPA) and the Army Corps of Engineers proposed changes to the definition of “waters of the United States” (WOTUS). These changes could narrow federal protections for certain waters under the Clean Water Act (CWA). This September 2026 supplementary proposal follows an earlier proposal issued in November 2025 and presents additional options for determining which waters qualify for federal protection. 

The proposed changes could significantly affect Tribal Nations, particularly those that rely on federal implementation of the CWA or are in areas with seasonal waters. One proposed change would limit federal protection to “perennial waters,” or waters that contain or continuously carry water throughout the year under normal conditions. This change could exclude seasonal streams, wetlands, and other water bodies from federal CWA jurisdiction, even when those waters are important to Tribal communities, ecosystems, agriculture, and cultural practices.  

Although EPA and the Army Corps have said these changes would provide greater clarity and predictability for agricultural producers, how these changes affect farming and ranching on Tribal lands will depend largely on how each Tribe chooses to regulate water quality in the absence of federal regulation. Some Tribes administer CWA programs under Treatment in a Similar Manner as a State (TAS) status or through their own regulatory agencies, while others rely on federal protections.  

Narrowing federal jurisdiction over waters could clarify requirements and reduce regulatory burdens for producers, but it could also leave some waters without water-quality standards, routine testing, or federal limits on direct discharges. Tribes with their own water quality programs might still be affected by upstream pollution.  

Changing the WOTUS definition could also affect Tribal producers downstream. Pollution entering an upstream waterway could reach Tribal agricultural operations, increase food-safety risks, and potentially increase regulatory burdens under other federal laws, such as the water quality testing required for certain produce growers under relevant Food Safety Modernization Act (FSMA) regulations.  

The supplementary proposal is open for public comment until October 9, 2026.