Intermittently Sensible: Interpreting EPA's Guidance on Clean Water Act Jurisdiction

You have land that you want to develop, but there is water on that land. Does that mean the federal government can regulate it, requiring you to get a costly permit before you can start? The answer, according to a recent Supreme Court decision and guidance issued by the Environmental Protection Agency (EPA), depends on the type of wetland on your property—along with its proximity to a navigable waterway.

Section 404 of the Clean Water Act (CWA) prohibits the discharge of pollutants and fill material into "navigable waters" without a permit. Under the act, "navigable waters" are defined as "waters of the United States, including the territorial seas." Relying on earlier court decisions, the EPA and the U.S. Army Corps of Engineers previously interpreted the phrase "waters of the United States" very broadly, applying the CWA not just to lakes, rivers, and streams that could be used for interstate commerce—termed "traditional navigable waters"—but also to wetlands adjacent to such waters and stream beds that are dry for most of the year. In 2001, however, the Supreme Court limited the act's reach by holding that the CWA did not apply to isolated, intrastate wetlands.

Recently, the Supreme Court had the opportunity to address the scope of the federal government's authority under the act in Rapanos v. United States, and although many had hoped that Rapanos would bring clarity, the court's splintered 4-1-4 decision has created even more uncertainty. In response, the EPA and the Corps issued a joint guidance to clarify which wetlands and waters are covered by the CWA. The implications of the Rapanos decision and the joint guidance are outlined below. It is important to note, however, that there may be additional wetland protection laws on the state or local level that are beyond the scope of both the guidance and this article.

I. Parsing Rapanos

The Supreme Court issued three principal opinions in the Rapanos case. The four-person plurality decision, written by Justice Scalia, vehemently rejected the agencies' broad interpretation of the CWA jurisdiction, concluding that the CWA should only apply to "those relatively permanent standing or continuously flowing bodies of water … that are described in ordinary parlance as streams, oceans, rivers, and lakes" and that only those wetlands with a continuous surface connection to such waters can be regulated under the act.

Writing alone, Justice Kennedy argued that CWA jurisdiction should instead be determined under a case-by-case approach, with the relevant agency examining whether a particular water or wetland has a "significant nexus" to waters "that are or were navigable in fact or that could reasonably be so made."

Finally, Justice Stevens, writing for the dissenters, sought to uphold the agencies' broad interpretation of the CWA. But because the four dissenters would support CWA jurisdiction over any water that meets either the plurality or "significant nexus" test, Justice Stevens argued that CWA jurisdiction should remain over any water that satisfies either standard. Doing the math, the agencies have adopted this approach in their recently issued guidance.

II. The EPA/Corps Guidance

In the EPA/Corps joint guidance, the agencies use both the plurality and "significant nexus" tests in asserting jurisdiction over different types of waters and wetlands. For a graphical representation of these types, please see Table 1. The numbers below correspond to areas designated on the map in Table 1.

A. Automatically Jurisdictional

The agencies will always assert jurisdiction over the following waters and wetlands:

• Traditional navigable waters (1)


• Wetlands with a continuous surface connection to traditional navigable waters (2)


• Wetlands adjacent to—but not actually abutting—traditional navigable waters (3)


• Relatively permanent non-navigable tributaries (4) that have flow or standing water for at least "some months"


• Wetlands with a continuous surface connection to relatively permanent non-navigable tributaries (5)

B. Significant Nexus Test

The agencies will also assert jurisdiction over other waters and wetlands if they have a "significant nexus" to a traditional navigable waterway. But what is a significant nexus? The agencies will evaluate these wetlands based on the following hydrological and ecological factors:

• The volume, duration, and frequency of flow in a tributary


• The tributary's proximity to traditional navigable waters


• Other hydrologic factors including the size of the watershed, average annual rainfall, and size of the average annual snow pack


• The potential for tributaries to carry pollutants and flood waters to traditional navigable waters


• Habitat for commercially or recreationally important species that inhabit downstream navigable waters


• The potential of wetlands to trap and filter pollutants or store flood waters


• The maintenance of water quality in traditional navigable waters

In applying these factors, the agencies will not ask whether a wetland or tributary alone has the requisite nexus, but rather whether it has that nexus together with other "similarly situated" wetlands (i.e, wetlands adjacent to the same tributary). The waters governed by the "significant nexus" standard include:

• Wetlands adjacent to—but not actually abutting—a relatively permanent non-navigable tributary (6)


• Intermittent non-navigable tributaries, whether they flow into a relatively permanent stream (7) or directly into traditional navigable waters (8)


• Wetlands adjacent to intermittent streams, whether they have a continuous surface connection (9) or not (10)

Finally, although isolated wetlands (11) are outside the act's reach, the agencies must first determine whether those wetlands are in fact isolated. The farther a wetland is from a navigable waterway, the more likely it will be deemed isolated and thus non-jurisdictional under the CWA.

III. Conclusion

Although the Rapanos plurality sought to sharply restrict CWA jurisdiction, the post-Rapanos landscape is not all that different from the pre-Rapanos one. The practical effect of Rapanos may have been to supplant the relative clarity of the prior law with even greater ambiguity under the "significant nexus" test. And because this test gives the agencies enormous discretion in deciding whether to assert CWA jurisdiction, landowners may find it difficult to challenge a jurisdictional determination.

Yet, despite the uncertainty created by Rapanos, the guidance gives a general sense of how Justice Kennedy's "significant nexus" test will be applied on the ground. The gist of it is this: The closer a wetland on your property is to a navigable waterway, the greater impact it has on waterways, and the greater the flow and duration of any neighboring tributaries, the more likely the federal government is to require you to get a permit before developing it. So long as the agencies justify their jurisdictional decisions, they should be able to regulate most of the wetlands that were jurisdictional prior to Rapanos.