How the 'Continuous Surface Connection' Test is Reshaping US Wetland Protections

Most Americans assume the Clean Water Act serves as a blanket shield for all water within the country's borders. In reality, the law's reach has always been tethered to a complex legal definition known as the "Waters of the United States," or WOTUS. For decades, the exact boundaries of that definition have been the subject of intense debate among landowners, conservationists, and federal regulators.[2]

That debate reached a critical turning point in 2023 with the Supreme Court's landmark decision in Sackett v. EPA. The ruling fundamentally altered how the federal government evaluates wetlands and streams, shifting the standard from ecological impact to physical geography.[3]

Prior to the Sackett decision, the Environmental Protection Agency (EPA) relied on the "significant nexus" test. Under that framework, a wetland was federally protected if it significantly affected the chemical, physical, or biological integrity of downstream navigable waters—even if it was geographically isolated. The Supreme Court rejected this approach, ruling that the EPA had overstepped its statutory authority.[2]

In its place, the Court established the "continuous surface connection" test. To qualify for federal protection today, a wetland must physically abut a relatively permanent body of water, making it difficult to determine where the water ends and the wetland begins.

The shift has profound implications for the American landscape, particularly in the arid West. Ephemeral streams—which only flow after rainfall or snowmelt—and isolated wetlands that connect to larger bodies of water via underground aquifers no longer meet the threshold for federal oversight.[1]

By some estimates, the revised standard removes federal Clean Water Act protections from roughly 63 percent of the country's wetlands and nearly five million miles of streams. This means that developers, agricultural operations, and landowners no longer need federal dredge-and-fill permits to alter these specific areas.

For industry groups and property rights advocates, the new framework provides much-needed regulatory clarity. The continuous surface connection test establishes a visible, predictable boundary that landowners can assess without requiring costly environmental consultants to prove or disprove a "significant nexus."

However, watershed scientists caution that the legal boundary does not reflect ecological reality. Wetlands act as natural sponges, storing excess water during heavy rains and slowing runoff. Even isolated wetlands that lack a surface connection play a critical role in mitigating downstream flooding and filtering pollutants before they reach major rivers.[1]

In response to the Supreme Court's mandate, the EPA issued a conforming rule in late 2023 and subsequently proposed further revisions to clarify lingering ambiguities, such as how to define a "wet season" for streams that flow intermittently.[2]

As the federal government narrows its scope, the regulatory burden is shifting to individual states. About half of U.S. states already have their own wetland protections on the books, but many others have historically relied entirely on the EPA and the Army Corps of Engineers to limit pollution and manage development.[1]

In regions where federal protections have evaporated, some state governments are now stepping in to fill the gap. Colorado, for example, recently launched its own comprehensive dredge-and-fill permitting program, known as Regulation 87, specifically designed to protect the seasonal streams and isolated wetlands left vulnerable by the Sackett decision.

New Mexico is currently developing a similar state-level permitting system to regulate pollutant discharges in state waters that exceed the new federal definitions. These localized efforts require significant administrative capacity, as state environmental departments must now process permits and conduct site evaluations that were previously handled by federal agencies.

Ultimately, the United States is moving toward a decentralized patchwork of water regulations. While the Clean Water Act continues to safeguard major rivers, lakes, and coastal waters, the fate of the nation's smaller streams and isolated wetlands will increasingly depend on the specific state in which they are located.[1][3]