Defining the “Waters of the United States”

Daren Bakst

For decades, the Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers (Corps) have struggled to develop a definition of “waters of the United States.”  This definition is critical because it helps to clarify what waters the agencies can regulate under the Clean Water Act.

In 2015, the Obama Administration published its controversial Clean Water Rule that sought to define “waters of the United States.”  However, in so doing, the agencies came up with a definition that was even more expansive than past overbroad interpretations.

From the start of the Trump Administration, the agencies have taken action to repeal the Clean Water Rule and to develop a new rule that provides clarity to regulated parties, recognizes the state role in the implementation of the CWA, and is consistent with the rule of law.

On February 14, 2019, the agencies published their proposed rule defining “waters of the United States.”

To help provide important information and analysis on this proposed rule, the Federalist Society hosted a teleforum entitled “Analyzing the New Proposed Rule Defining ‘Waters of the United States.”

This event provided some historical background, identified why a proper definition is so important, and discussed key principles that should inform any new rule, including the need for regulated parties to know what waters are even regulated.

The program them went through the categories of waters included in the proposed definition of “waters of the United States,” discussed concerns with the definition, and identified some recommended changes.

For example, the proposed rule in defining what are considered “traditional navigable waters” takes a far too expansive view of the type of commerce that must be conducted on a water. One of the key recommendations, consistent with past case law, was to ensure that the water could serve as a means to transport interstate or foreign commerce.

The proposed rule properly excludes ephemeral waters (waters consisting of surface water resulting from precipitation) but fails to exclude intermittent waters.  As drafted, the inclusion of intermittent waters could lead to significant confusion and is inconsistent with Justice Scalia’s plurality opinion in Rapanos v. United States (a leading U.S. Supreme Court case on “waters of the United States”).

The program discussed the need to exclude intermittent waters and to include seasonal waters consistent with Scalia’s plurality opinion, ensuring that waters are “relatively permanent,” “continuously flowing,” and can be described as having the “ordinary presence of water.”

Other discussions focused on adjacent wetlands, ditches, and whether the proposed rule was consistent with Justice Scalia’s plurality opinion (and whether it should be).

To learn about the proposed rule and the “waters of the United States” issue, listen to the podcast of this timely and informative program via the link at the bottom of the page.

Daren Bakst

Senior Research Fellow in Agricultural Policy

The Heritage Foundation


Federalist Society’s Environmental Law & Property Rights Practice Group

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