ICV Public Comment on Updated Definition of “Waters of the United States”

Indiana Conservation Voters submitted the following public comment to the U.S. Environmental Protection Agency in October 2026.

U.S. Environmental Protection Agency
EPA Docket Center
Office of Water Docket, Mail Code 28221T
1200 Pennsylvania Avenue NW
Washington, DC 20460

RE: Updated Definition of “Waters of the United States”
Docket ID No. EPA–HQ–OW– 2025–0322

To whom it may concern:

Indiana Conservation Voters strongly opposes the supplemental options in EPA and the Army’s September 9, 2026 supplemental notice (91 FR 57284) and the November 2025 proposed rule (90 FR 52498) revising the definition of “Waters of the United States.”  We urge EPA and the Army Corps of Engineers to withdraw both. These rules would remove Clean Water Act protections from a large share of our waterways; nationwide they would put at least 90% of wetlands and 60% of streams at risk of losing federal protection. The result would be greater danger to public health, greater danger to public safety, and higher costs for Hoosier communities.

Public Health

The Clean Water Act is a public health law. Its permits, pollution limits, monitoring, reviews, grants, and restoration plans keep harmful pollution out of the water Hoosiers drink, swim in, and fish from. But these tools only work for waters the Act covers. The Supreme Court’s 2023 Sackett decision already narrowed that coverage, and the proposed rule would narrow it further: as little as 12% of Indiana’s streams would remain federally protected. With the rest unprotected, more pollution from both pipes and runoff would go unchecked and unmonitored, putting the health of Hoosier families at risk; the 2025 proposal itself states that waters not included in the WOTUS definition are not required to be assessed or listed as impaired.

EPA’s own analysis found that more than 1.7 million Hoosiers are served by public drinking water systems that rely at least in part on intermittent, ephemeral, or headwater streams (based on 2006 data). EPA expects most intermittent streams would not qualify as “relatively permanent” under the supplemental option, leaving those communities vulnerable to increased pollution and poorer water quality.

Affordability

Hoosiers depend on strong federal clean water protections like NPDES permitting and Section 303 water quality standards and TMDL programs. Hoosier communities are already in need of additional funding to maintain and improve their water infrastructure. By shifting the costs of lost wetland and stream protections onto local governments and ratepayers, the proposed rule would increase demand for Clean Water State Revolving Fund loans and other federal funding that is already limited. Communities would face higher water-quality costs while competing for the same limited funds.

Indiana has already lost approximately 85% of its historic wetlands. Using the DNR’s estimations of the value of wetland services, Indiana’s remaining wetlands (as of 2022) provide an estimated $2.8 billion annually in flood mitigation, water treatment, and stormwater management services.* Every additional wetland and stream that loses protection pushes costs onto local governments and ratepayers, who must build and maintain replacement infrastructure.  The proposed rule and supplemental notice would put up to $2.4 billion at risk in lost annual services statewide.†

Public Safety

Wetlands absorb and slow stormwater before it reaches homes, roads, and businesses. Indiana is seeing more short, intense storms, like those in August 2026 that caused record-breaking floods and millions of dollars in damage in central Indiana. Areas with restored wetlands, or downstream from them, saw less severe flooding than they otherwise would have. Yet the proposed rule would protect as little as 0.04% of Indiana’s remaining wetlands, far below the national figure of 5.7%. With so little protection left, future storms would increase the risk of property damage, injuries, and loss of life.

Reliance Interest

The supplemental notice asks about reliance interests and acknowledges that some states have laws restricting them from being more stringent than federal rules. Indiana is one of those states. Under Indiana’s “no more stringent than” policy, the Indiana Department of Environmental Management (IDEM) relies heavily on EPA’s regulatory guidance to ensure consistent water quality and environmental health. Streams and wetlands that lose federal coverage cannot readily be picked up by the state, leaving limited protections for waters Indiana relies on for drinking water, recreation, habitat, and community. The supplemental options also go beyond what the courts require: EPA’s own notice acknowledges that lower courts have held Sackett does not require a surface water connection. This proposal would leave Indiana’s waters and residents exposed to unchecked pollution and habitat loss, and the EPA should not adopt them.

Conclusion

The Clean Water Act was passed in response to pollution and neglect of our waterways. This rule would undo decades of progress and public investment, and Hoosier communities would be left to pay for the cleanup. The EPA’s own Regulatory Impact Analysis of the underlying rule recognizes the risks and costs to communities, but prioritizes unquantified cost benefits to industries for largely irreversible damage to our natural resources and infrastructure. For these reasons, nearly 100 Hoosiers in our network have submitted a public comment or signed a petition opposed to these changes, and Indiana Conservation Voters urges EPA and the Army Corps of Engineers not to further reduce Clean Water Act protections.

Respectfully submitted,

Indiana Conservation Voters
October 9, 2026