Comment
Re: Supplemental Notice of Proposed Rulemaking, Updated Definition of “Waters of the United States,” Docket ID No. EPA-HQ-OW-2025-032
The National Association of State Departments of Agriculture (NASDA) appreciates the opportunity to provide comments on the U.S. Environmental Protection Agency’s (EPA) and U.S. Army Corps of Engineers’ (Corps) (collectively, the “Agencies”) supplemental notice of proposed rulemaking regarding the definition of “waters of the United States” (WOTUS) under the Clean Water Act (CWA).
NASDA represents the commissioners, secretaries, and directors of the state departments of agriculture in all fifty states and four U.S. territories. State departments of agriculture are responsible for a wide range of programs, including conservation, environmental protection, food safety, plant and animal disease prevention, and fostering the economic vitality of rural communities. Several state departments of agriculture also administer or partner in administering Section 402 National Pollutant Discharge Elimination System (NPDES) permitting programs for Concentrated Animal Feeding Operations (CAFOs).
NASDA and our members support regulatory approaches that provide predictability to regulated entities and property owners while rejecting overly broad interpretations of federal authority. The CWA establishes a cooperative framework between federal and state governments to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. Central to this framework is the recognition that states retain primary responsibility for planning the development and use of their water resources. Federal policies must respect state laws governing water rights and allocations and afford states maximum flexibility in managing their water resources and water quality programs.
NASDA appreciates the Agencies’ continued efforts to establish a clear, durable definition of WOTUS consistent with the Supreme Court’s decision in Sackett v. EPA. In particular, NASDA recognizes the supplemental proposal’s progress towards providing greater regulatory certainty through revised definitions of “relatively permanent” waters and “continuous surface connection.” While these revisions move in a constructive direction, additional clarification and refinement remain necessary to ensure the definitions are durable, workable, and consistent with the statutory limits of federal jurisdiction. NASDA also endorses the detailed technical comments of the Waters Advocacy Coalition (WAC), of which NASDA is a member. The following comments emphasize considerations particularly relevant to state departments of agriculture and the agricultural producers they serve.
I. Relatively Permanent Waters and Continuous Surface Connection
NASDA supports the Agencies’ efforts to establish clear and consistent definitions of “relatively permanent” waters and “continuous surface connection” that reflect the statutory limits of federal jurisdiction. The supplemental proposal’s emphasis on perennial waters represents an improvement over the previously proposed wet-season approach and helps address longstanding concerns regarding the treatment of intermittent and ephemeral water features. However, additional clarity is needed to ensure these standards can be implemented predictably across diverse landscapes and hydrologic conditions. NASDA has consistently advocated for definitions that provide regulatory certainty to agricultural producers and landowners while respecting the limitations on federal authority. A clearly defined standard for relatively permanent waters can reduce ambiguity for agricultural activities, including irrigation, drainage, conservation, and other routine land management practices.
NASDA likewise appreciates the Agencies’ efforts to clarify that wetlands must maintain a continuous surface water connection with an otherwise jurisdictional water to qualify as WOTUS. This approach moves closer to aligning with the Supreme Court’s emphasis in Sackett that jurisdictional wetlands must be practically indistinguishable from covered waters, rather than merely adjacent or geographically proximate. Such distinctions are particularly important for agricultural operations involving wetlands, drainage features, and other water resources subject to varying hydrologic conditions. NASDA encourages the Agencies to finalize definitions that establish clear jurisdictional boundaries, distinguish federally regulated waters from those under state authority, and provide a consistent foundation for implementation.
II. State Water Management and Regional Hydrology
Clear federal jurisdictional boundaries must also account for states’ longstanding authority over water rights, allocation, and agricultural water management. Agricultural operations across the country depend on state-authorized irrigation withdrawals, water diversions, storage systems, and other practices that may influence the timing, duration, and availability of surface water flows. Section 101(b) of the CWA expressly recognizes states’ primary responsibilities for planning the development and use of their land and water resources. Accordingly, NASDA encourages the Agencies to clarify how authorized water management activities, including irrigation diversions and other lawful interruptions of surface flow, will be considered when determining whether a waterbody is “relatively permanent” or maintains a “continuous surface connection.” These determinations must respect existing state water rights and allocation systems and avoid creating unnecessary uncertainty for agricultural producers conducting lawful water management activities.
The importance of clear implementation standards is further underscored by the considerable variation in hydrologic conditions across the United States. Differences in seasonal precipitation, drought frequency, irrigation practices, and streamflow patterns, particularly between arid western states and regions with more consistent surface water availability, can complicate the application of uniform federal standards. While NASDA supports nationally consistent jurisdictional definitions, their implementation must recognize regional hydrologic variability and rely on sound science and reliable data.
NASDA is particularly concerned about the Agencies’ proposed use of the U.S. Drought Monitor to evaluate anomalous hydrologic conditions. While the Drought Monitor provides valuable information about regional drought severity, it was not designed to determine the hydrologic characteristics or
jurisdictional status of individual waterbodies under the CWA. Its convergence-of-evidence methodology may be appropriate for assessing regional drought conditions but does not necessarily provide the precision required for site-specific jurisdictional determinations. Accordingly, NASDA urges the Agencies not to rely solely on Drought Monitor classifications when evaluating whether interruptions in surface flow constitute anomalous conditions. Instead, such determinations should incorporate site-specific hydrologic data, regional climatic conditions, and input from applicable state agencies to ensure decisions are scientifically sound, transparent, and consistently applied.
State departments of agriculture and other state natural resource, conservation, and environmental agencies possess valuable regional expertise that should inform the development of guidance that is both consistent nationwide and practical under differing climatic conditions.
III. Regulatory Certainty and Implementation
For agricultural producers and landowners, regulatory certainty depends not only on clearly written definitions but also on their consistent application. NASDA has long emphasized that determining whether a water feature is subject to federal jurisdiction should not require costly technical assessments or legal consultation. The supplemental proposal takes steps toward greater predictability by establishing objective criteria for temporary interruptions in surface flow, including the proposed allowance for a single interruption of up to 30 consecutive days under non-anomalous conditions and the treatment of prolonged drought. To ensure these provisions achieve their intended purpose, NASDA encourages the Agencies to clarify how ordinary conditions, recurring interruptions, and the proposed five-year timeframe for anomalous events will be evaluated. Important jurisdictional criteria should be clearly articulated in the final regulatory text, where appropriate, to minimize uncertainty and inconsistent interpretation.
Consistent implementation will also require transparent and scientifically sound procedures for making jurisdictional determinations across Corps districts. Hydrologic models, mapping databases, and other assessment tools can provide useful information, but their application must account for their limitations, particularly when evaluating agricultural lands with variable hydrologic conditions. Such tools should not serve as the sole basis for asserting federal jurisdiction without sufficient supporting evidence. NASDA encourages the Agencies to establish clear guidance governing the use of these resources, provide adequate documentation of jurisdictional determinations, and promote timely and consistent decision-making. These measures are essential to reducing unnecessary compliance costs and delays while ensuring that federal jurisdiction remains within the boundaries established by the CWA and Sackett.
IV. Cooperative Federalism
The distinction between federal and state jurisdiction is fundamental to the cooperative federalism framework established under section 101(b) of the CWA. NASDA has consistently emphasized that waters falling outside federal jurisdiction are not unregulated or unprotected. States maintain statutory
authorities, regulatory programs, and voluntary conservation initiatives designed to address water quality concerns and protect natural resources. State departments of agriculture contribute to these efforts through conservation programs, technical assistance, and partnerships with agricultural producers. Accordingly, NASDA urges the Agencies to recognize and defend the effectiveness of existing state-led programs and retract all prior statements equating a reduction in federal jurisdiction with a corresponding reduction in water quality protections.
Meaningful engagement with state partners will be essential as the Agencies finalize and implement the revised WOTUS definition. States possess institutional knowledge and practical experience in managing water resources and administering environmental programs across diverse geographic, climatic, and regulatory conditions. NASDA encourages the Agencies to consult with state departments of agriculture when developing implementation guidance, respect existing state authorities, and avoid unnecessarily duplicating state regulatory programs. Preserving flexibility for states to address water quality concerns through approaches suited to their individual needs will help maintain an appropriate balance between federal oversight and state responsibility.
V. Conclusion
NASDA appreciates the Agencies’ efforts to establish a clear, durable, and legally defensible definition of WOTUS consistent with the CWA and the Supreme Court’s decision in Sackett v. EPA. NASDA supports the direction of the supplemental proposal and encourages the Agencies to incorporate the technical clarifications outlined in WAC’s comments. Establishing clear jurisdictional boundaries, ensuring consistent implementation, and respecting state authority will provide greater regulatory certainty for agricultural producers and landowners while preserving the cooperative federalism principles underlying the CWA.
NASDA remains committed to working with the Agencies, and other state and federal partners to support effective water quality protection while respecting states’ primary responsibilities for managing land and water resources. We appreciate the opportunity to comment and look forward to continued engagement as the Agencies finalize and implement this rulemaking.
If you have any questions, please contact Logan Moss, Associate Director of Public Policy(logan.moss@nasda.org).
Sincerely,
Ted McKinney
CEO
NASDA
