Key Points

• The Supreme Court holds that the Clean Water Act can regulate only those wetlands with a continuous surface connection to relatively permanent, standing or continuously flowing body of water (like streams, oceans, rivers, or lakes) so that they are “indistinguishable” from that water.
• While this new test narrows the scope of federal regulation, California’s existing wetlands regulations remain, leaving few if any wetlands in California unregulated.

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For five decades, the Clean Water Act has been vital to improving the quality of our nation’s waters. But since inception, which waters the Act can regulate has never been clear. On May 25, 2023, the U.S. Supreme Court tried to provide some clarity in Sackett v. Environmental Protection Agency.

The Clean Water Act’s uncertainty emerges from its definition of navigable waters as “waters of the United States,” which are what the U.S. Environmental Protection Agency and Army Corps of Engineers can regulate under the Act. But that phrase has no commonly understood meaning. So which waters these federal regulators regulate often changed with each new presidential administration. As we have reported, these changes resulted in regulatory volleyball that made the uncertainty worse.

This uncertainty reaches a nadir with wetlands. And as we have also explained, difficulties delineating where land ends and water begins make it challenging to know whether filling a wetland needs a federal or state permit, both, or neither. The Sacketts faced this challenge and sought the Supreme Court’s guidance after the Ninth Circuit held them liable for unpermitted filling of wetlands across a street from a lake.

In its majority opinion, the Supreme Court revived language from a 2006 plurality opinion that “waters of the United States” include “only those relatively permanent, standing or continuously flowing bodies of water ‘forming geographical features’ that are described in ordinary parlance as ‘streams, oceans, rivers, and lakes.’” This language, the Court explained, covers only some wetlands. While wetlands are features that depend on water, so too do other features like puddles. But the Act could not regulate puddles; nor could it regulate all wetlands simply because water is present.

To identify which wetlands are regulated under the Act, the Supreme Court fashioned a new test: those wetlands that are “indistinguishably part of a body of water that itself constitutes ‘waters’ under the [Act].” This test means that “[w]etlands that are separate from traditional navigable waters cannot be considered part of those waters, even if they are located nearby.”

This test provides needed clarity, which may slow the regulatory volleyball that has plagued the regulated community and environmentalists alike. But that back-and-forth may not be at its end. We can soon expect Army Corps guidance on implementing Sackett, followed by new regulations. And perhaps Sackett will prompt Congress to rethink and amend this half-century-old statute.

Whatever the outcome of those efforts, its impact in California will be more muted than elsewhere. As California recently expanded its regulation of wetlands through the State Wetland Definition and Procedures for Discharges of Dredged or Fill Material to Waters of the State, few if any waters in California are unregulated. Be sure to stay apprised as these laws change. And should you have any questions or concerns about how these laws affect you, contact our Water Law attorneys.