June 20, 2024

Protecting Navigable Waters One Year After the Supreme Court’s Sackett Decision


  • Federal wetlands protections under the Clean Water Act were weakened after the Supreme Court’s Sackett v. Environmental Protection Agency case.
  • At least 290 million acres of wetlands are at risk of being lost to development and pollution.
  • State and local jurisdiction to protect wetlands will be necessary post-Sackett.
  • Visit our resource list to read more about how states and other organizations are responding to the change.
View of the land and the river in the Ashley River Historic District near Drayton Hall

photo by: Drayton Hall

View of the wetlands along the Ashley River near Drayton Hall, a National Trust Historic Site.

One year after the Supreme Court’s decision in Sackett v. Environmental Protection Agency, 143 S. Ct. 1322, 1344 (2023), stripped away federal protections for wetlands under the Clean Water Act, conservationists—and preservationists—still have more questions than answers on how to protect America’s wetlands, and the impact of the decision on other federal protections for historic resources.

On May 25, 2023, the Court decided that only waters with a “continuous surface connection” to “waters of the United States” are protected under the Clean Water Act. The use of the term “waters,” the Court further held, refers to “navigable water like rivers, lakes, and oceans”—not wetlands. At stake are countless wetlands at risk of being lost to development and pollution. According to Earthjustice, “[t]he United States has at least 290 million acres of wetlands—about twice the area of Texas—and at least 200 million miles of life-giving streams which do not flow year-round.”

Prior to the decision, the National Trust, Southern Environmental Law Center, and Natural Resources Defense Council, as part of a coalition of 114 environmental and community nonprofit organizations, filed an amicus curiae brief in June 2022 to “ensur[e] that the [Clean Water] Act is interpreted consistently with Congress’s stated objective to ‘restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.’ 33 U.S.C. § 1251(a).” The organizations advocated for a broader definition of “waters of the United States” to meet this objective. Now that the definition has been narrowed, advocates are coming together again—this time to protect wetlands on a state and local level.

The Impact and Response

While coastal wetlands and those surrounding large bodies of water have more obvious connections to “navigable water,” inland and isolated wetlands are at risk of falling outside this newly interpreted “waters of the United States” definition. For example, in New Mexico and Nevada, over 90 percent of the streams are classified as ephemeral or intermittent, and thus have now lost their prior federal regulatory jurisdiction.

In addition to the devastating impacts of the Sackett ruling on the environmental protection of clean water and streams, this decision has a potentially devastating impact on historic and cultural resources. The reason is that many private development projects that would harm or destroy historic resources have traditionally required an Army Corps of Engineers permit because of their impacts on wetlands. And that federal hook requires the Army Corps to comply with Section 106 of the National Historic Preservation Act and to “take into account” the impacts of the private development project on historic properties, prior to making a decision about whether or not to issue the permit.

Now that the Sackett decision has dramatically reduced the Army Corps’ jurisdiction over wetlands, many of those potentially harmful development projects will no longer require a Corps permit, and thus will have no federal environmental or historic preservation review at all. In some states, efforts are underway to enact state legislation establishing state jurisdiction over wetlands at pre-Sackett levels, and this can be especially helpful if the state has a good historic preservation review law, analogous to Section 106. For example, California, Maryland, New Mexico, Washington, and Wisconsin have adopted legislation to protect wetlands, and North Carolina has taken executive action to increase protection for wetlands.

These efforts mirror actions taken by states in response to other Supreme Court landmark decisions in other contexts, such as in Kelo v. City of New London, 545 U.S. 469 (2005). In response to Kelo, which confirmed the authority of the government to take private property for economic redevelopment, 47 states have enacted laws explicitly limiting the authority of state and local governments to do so. Although the context of the Kelo decision is very different, It is possible, and potentially desirable, for states to respond similarly to Sackett through state law to limit its damage.

View of the land and the river in the Ashley River Historic District near Drayton Hall

photo by: Drayton Hall

The Ashley River Historic District encompasses of wetlands near Drayton Hall, A National Trust Historic Site.

Interpreting Waters of the United States

On August 29, 2023, the Environmental Protection Agency (EPA) and the Army Corps amended their definition of “waters of the United States” to conform with the Sackett decision. The new rule, "Revised Definition of 'Waters of the United States'; Conforming," became effective on September 8, 2023. The agency has since conducted several listening sessions in February 2024 for stakeholder feedback on the new definition.

The public can monitor jurisdictional determinations on the EPA’s “Clean Water Act Approved Jurisdictional Determinations” database. According to the Database, the Army Corps has made 9,078 jurisdictional determinations based on post-Sackett regulations as of the publication of this article. Only 1,835 projects were categorized as waters of the United States under the new regulations.

Shortly before Sackett was decided, the EPA published a new definition of navigable waters (Revised Definition of `Waters of the United States'). The revisions went into effect on March 20, 2023. As of September 2023, 27 states had challenged the new regulations. However, once Sackett was decided, the agencies revised the standard to conform with the Court’s interpretation of the definitions in Sackett.

Next Steps

While the Court’s new interpretation of the definitions appears to leave many wetlands without federal protections, one thing remains clear—advocates must continue their work to protect them. Advocates should shift their efforts to enacting state legislation to prevent further loss of these integral landscapes. The National Trust will continue to monitor the aftermath of the Sackett decision and its effects on wetland conservation.

Elizabeth Merritt, deputy general counsel, Christopher Cody, associate general counsel, and Murphey Chen, 2023 Law Division intern, contributed to this article. News articles compiled Morgan Breene, 2024 Law Division intern.

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Jade McClary is an associate general counsel in the Law Division at the National Trust for Historic Preservation.

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