Navigable waters

The Clean Water Act (CWA) explicitly calls for the federal government to protect “navigable waters.” EPA and the Army Corps of Engineers defines the term navigable waters as “waters of the United States” (WOTUS), including the territorial seas. While WOTUS has been subject to debate and litigation over the years, the latest regulatory definition outlines the categories of waters that are currently considered “waters of the United States.” These jurisdictional waters include:

• The territorial seas and waters (also known as traditional navigable waters) which are currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including waters which are subject to the ebb and flow of the tide;
• Tributaries;
• Lakes and ponds, and impoundments of jurisdictional waters; and
• Adjacent wetlands.

The regulatory definition also outlines 12 waters or features that are not considered WOTUS, by definition. See the complete definition of “waters of the United States” in the Key Definitions section below.