Current State of Wetland Regulations
On March 12, 2025, the U.S. Environmental Protection Agency (USEPA) issued a memorandum on guidance for implementation of the definition of “Waters of the United States” to respond to feedback for clarification on what constitutes a “continuous surface connection” with a Traditional Navigable Water which requires a water resource be subject to Federal regulation under Section 404 of the Clean Water Act (CWA). The intent is to give the U.S. Army Corps of Engineers (USACE) guidance on how to implement the most recent definition of jurisdictional “Waters of the United States” based on the Supreme Court’s decision in Sackett v. Environmental Protection Agency (2023) and Rapanos v. United States (2006).
In Rapanos, Justice Kennedy provided that a “significant nexus” which included evaluation of the existence of a chemical, physical, or biological connection of wetlands to downstream Traditional Navigable Waters, as an appropriate demonstration of jurisdictional connection. However, in Sackett, it was ruled that only wetlands with a “continuous surface connection” to bodies of water that are “Waters of the U.S.” can be considered jurisdictional under the Clean Water Act.
Under Sackett, only wetlands that directly abut, or touch, a “Waters of the U.S.” and maintain a “continuous surface connection” where it is “difficult to determine where the water ends and the wetland begins” can be considered jurisdictional and subject to Section 404 CWA regulations.
So, what does this mean for wetland regulations in the United States? Only intermittent and perennial streams and the wetlands that share a boundary with them are currently subject to protection under the Clean Water Act. Any wetlands outside of this definition are not regulated under federal law and are considered to be isolated wetlands. Some states have laws that provide some protection for wetlands. Indiana is one of the 19 states that has isolated wetland protections (according to the Environmental Law Institute); however, the landscape of those protections has been changing over the last 4 years.
In Indiana, some wetlands that are not regulated under the Federal CWA are subject to regulation under the State Regulated Wetlands Law (also known as the Indiana Isolated Wetlands Law). This law has been in effect since 2004 but has recently undergone changes due to Senate Enrolled Act 389 (SEA 389) which was passed in2021. Isolated wetlands are assigned a classification of Class I, II, or III, with III being the highest quality. Wetland quality is assigned by wetland scientists in the field in conjunction with coordination with IDEM, and considers factors such as amount of human disturbance, plant species diversity, hydrological function, location in the landscape, and significance of the wetland to provide habitat for wildlife.
SEA389 significantly reduced protection for Indiana isolated wetlands in multiple ways. The State Regulated Wetlands Law was changed to provide several increases in exemptions for the number of isolated wetlands that could be impacted by fill without requiring a permit and potential mitigation for loss of wetlands. Those exemptions now include all Class I wetlands regardless of size(previously protected up to certain sizes with mitigation required for higher amounts of impacts); Class II wetlands in rural areas up to 3/8 acre in size; Class II wetlands located within the boundaries of a municipality up to ¾ acre in size; and all voluntarily created wetlands other than mitigation wetlands. Exemptions become more complicated when sites contain more than one Class II wetland and require additional calculations to determine which portion of these wetlands are exempt. Impacts to isolated wetlands outside of the exemptions listed above and all impacts to Class III wetlands still require a State Regulated Wetlands permit.
Indiana has lost 85% of its wetlands since settlement (according to the Indiana Department of Environmental Management). The majority of remaining wetlands in the state, up to 80-90%, are isolated wetlands (Hoosier Environmental Council).These regulation changes will increase the rate of wetland loss at a time when climate change and increases in severe weather are producing increased flooding which these important ecosystems help to regulate. Wetlands have many essential functions in the landscape in addition to flood control, including water quality management and providing critical habitat for many wildlife species including endangered, threatened, and rare species. Changes in federal and state level regulations affect the future existence of this important natural resource and contribute to the loss of critical wetland functions including public health. It will be left up to the public to deal with the consequences of wetland loss that will continue to occur because of these regulation changes. Improvements to infrastructure and the built environment must consider wetlands as an important natural resource to be protected and maintained through conscientious management versus a nuisance and impediment to development.
Our Metric Natural Resources teams have expertise in wetland and stream assessment and mitigation. We assist our clients with understanding and complying with State and Federal Clean Water Act regulations concerning impacts to Waters of the U.S./Waters of the State and in the protection of other precious natural resources.
