As a result of the U.S. District Court for the District of Arizona’s August 30, 2021 order vacating and remanding the Navigable Waters Protection Rule (“NWPR”), discussed in our prior post, the Environmental Protection Agency and U.S. Army Corps of Engineers (collectively the “Agencies”) have halted implementation of the NWPR nationwide. The Agencies are interpreting “waters of the United States” (“WOTUS”) consistent with pre-2015 regulations, which were first promulgated in 1986 and subsequently modified by two Supreme Court decisions, Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (“SWANCC”) and Rapanos v. United States, and associated Agency guidance. This means that the federally jurisdictional scope of WOTUS under the Clean Water Act, including wetlands, will be determined pursuant to the latest guidance developed by the Agencies in 2008 (the “2008 Guidance”).

A brief summary of 2008 Guidance can be found below. We note, however, that given the abrupt shift in the regulatory regime, as well as the often contested “significant nexus” analysis codified in the 2008 Guidance, it is very likely that the speed by which the Agencies will process Section 404 applications will slow, and the scope of federally jurisdictional waters, particularly wetlands, will increase. Please note that the Agencies have indicated that they will continue to move forward with the rulemaking, announced on June 9, 2021, to revise the definition of WOTUS, the likely result of which will broaden the scope of water bodies subject to federal regulation compared to the now-vacated NWPR.

The 2008 Guidance stipulates that the Agencies will assert jurisdiction over the following waters:

• Traditional navigable waters;
• Wetlands adjacent to traditional navigable waters;
• Non-navigable tributaries of traditional navigable waters that are relatively permanent (i.e., the tributaries typically flow year-round or have continuous flow at least seasonally);
• Wetlands that directly abut such tributaries.

The Agencies will decide jurisdiction over the following waters based on a fact-specific analysis to determine whether they have a “significant nexus” with a traditional navigable water:

• Non-navigable tributaries that do not typically flow year-round or have continuous flow at least seasonally;
• Wetlands adjacent to such tributaries;
• Wetlands adjacent to but that do not directly abut a relatively permanent non-navigable tributary.

The Agencies generally will not assert jurisdiction over the following features:

• Swales or erosional features (e .g., gullies, small washes characterized by low volume, infrequent, or short duration flow);
• Ditches (including roadside ditches) excavated wholly in and draining only uplands and that do not carry a relatively permanent flow of water.

The Agencies will apply the significant nexus evaluation as follows:

• A significant nexus analysis will assess the flow characteristics and functions of the tributary itself and the functions performed by all wetlands adjacent to the tributary to determine if in combination they significantly affect the chemical, physical and biological integrity of downstream traditional navigable waters;
• Significant nexus includes consideration of hydrologic and ecologic factors.