The Environmental Protection Agency (“EPA”) has released its much-anticipated replacement for the 2015 Waters of the United States rule (“2015 Rule”). The new rule, released on January 23, 2020, reduces the types of waterways that fall under the jurisdiction of the federal Clean Water Act (“CWA”). It is a final rule, meaning that there will be no period for public comment or revision. Once the new rule goes into effect, it will be the law that governs which waterbodies are fall under the jurisdiction of the CWA.

The CWA is the main federal law aimed at governing water pollution. It prohibits “the discharge of any pollutant” into “the waters of the United States, include the territorial seas” without a permit. Enforcing and complying with the CWA hinges on knowing what is and what is not a water of the United States, also known as a WOTUS. When Congress passed the CWA in 1972, it granted EPA the responsibility of defining the key term.  In the decades since, there have been numerous regulatory and judicial definitions of the term, most recently in a 2015 proposed regulation.

The new rule, known as the Navigable Waters Protection rule, narrows the definition of WOTUS from how it was defined in the 2015 rule. As a starting point, the Navigable Waters Protection rule limits the types of waterways that will fall under the definition of WOTUS to four categories: (1) the territorial seas and traditional navigable waters; (2) perennial and intermittent tributaries of such waters; (3) certain lakes, ponds, and impoundments of jurisdictional waters; and (4) wetlands adjacent to other jurisdictional waters (other than waters that are themselves wetlands). Through these categories, EPA is seeking to bring clarity to the definition of WOTUS by establishing which waters do and which waters do not fall under the jurisdiction of the CWA.

After identifying the four categories of waters that will receive CWA protection, the Navigable Waters Protection rule continues to further define each category. The first category, “territorial seas and traditional navigable waters” includes those waters that “are currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide.” This essentially includes all waterways that have the physical capacity to support commercial navigation, such as the Pacific Ocean and the Mississippi River.

The second category of “perennial and intermittent tributaries” has been defined by the Navigable Waters Protection rule as rivers, streams, or similar naturally occurring surface waters that contribute surface water flow to territorial seas or traditional navigable waterways either directly or through another tributary, lake, pond, or adjacent wetland. Additionally, the tributary must be perennial or intermittent. The rule defines “perennial” as “surface water flowing continuously year-round” and “intermittent” is as “surface water flowing continuously during certain times of the year and more than in direct response to precipitation.” Therefore, a tributary under the Navigable Waters Protection rule must have a direct hydrologic surface connection with either a territorial sea or traditional navigable waterway, and it must either have water flowing through it year-round or if water only flows through it during certain times of the year it must not be only because of rain or snowfall. The rule specifically excludes from the definition of tributaries all surface waters that flow only in direct response to precipitation.

Under the new rule, the third category of “certain lakes, ponds, and impoundments” will come under CWA jurisdiction if they meet any one of three criteria: (1) if the waterway would meet the definition of a traditional navigable water like Lake Michigan or Lake Mead; (2) if the waterway contributes surface water flow to a territorial sea or a traditional navigable waterway; or (3) if the waterway is regularly flooded with water from a water of the United States. Essentially, any lake, pond, or impoundment – an enclosed waterbody – that is not itself a traditional navigable waterway, must share a surface connection with a jurisdictional water.

Finally, Navigable Waters Protection rule defines the fourth category of “adjacent wetlands” as those wetlands that touch a territorial sea, traditional navigable water, tributary, lake, pond, or impoundment of a jurisdictional water. A wetland will only be considered a WOTUS under the new rule if it has a direct hydrologic surface connection with another jurisdictional water. Wetlands that do not share any physical connection with a jurisdictional water will not receive CWA protection under the Navigable Waters Protection rule.

Along with defining what a WOTUS is, the Navigable Waters Protection rule also defines what a WOTUS is not. The rule outlines twelve categories of waters that are specifically excluded from CWA jurisdiction. Excluded waters include all groundwater, any surface water that flows only as a direct result of precipitation, most farm and roadside ditches, artificial lakes and ponds, and a variety of constructed water features.

Some welcome EPA’s new rule as bringing clarity to what has typically been a confusing regulatory landscape, made murkier by court cases that have lead to different WOTUS definitions across various jurisdictions. Others consider the Navigable Waters Rule to be a rollback of environmental protections.

The new rule is likely to have an impact on several on-going court cases, including some cases seeking to overturn the 2015 rule and some that were filed as a challenge to EPA’s 2019 repeal of the 2015 rule. It is also likely that the Navigable Waters Protection rule itself will face litigation.

The rule has not yet been published in the Federal Register, but once it has been, it will take effect 60 days after publication.


To read the pre-publication copy of the Navigable Waters Protection rule, click here.

To read the text of the Clean Water Act, click here.

To read the previous WOTUS regulatory proposals published by EPA, click here.

To read a previous National Agricultural Law Center publication about the definition of WOTUS, click here.

For more National Agricultural Law Center resources on the Clean Water Act, click here.