On June 5, 2007 the U.S. Environmental Protection Agency (EPA) and Army Corps of Engineers released a long-awaited interpretation of what constitutes “waters of the United States.” The two agencies jointly issued a legal memorandum that interprets the June 19, 2006 Supreme Court decision in the consolidated cases Rapanos v. U.S. and Carabell v. U.S. (known as the “Rapanos” decision). The guidance is being released to Corps of Engineers and EPA field offices in an attempt to ensure nationwide consistency in identifying wetlands, streams and rivers subject to the Clean Water Act (CWA).

To ensure such decisions are made in a timely manner, the agencies have released concurrently with the guidance a Memorandum of Agreement laying out a process with specific short timeframes, when necessary, for reaching interagency agreements on jurisdictional calls.

A summary released by the two agencies outlines the following key points:

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 where the tributaries typically flow year-round or have continuous flow at least seasonally (e.g., typically three months)
• Wetlands that directly abut such tributaries

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

• Non-navigable tributaries that are not relatively permanent
• Wetlands adjacent to non-navigable tributaries that are not relatively permanent
• Wetlands adjacent to but that do not directly abut a relatively permanent non-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 that do not carry a relatively permanent flow of water

The agencies will apply the significant nexus standard as follows:

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

According to a fact sheet released by the two agencies, “The objective of this guidance is to clarify requirements for CWA jurisdictional determinations (JD) following the Supreme Court’s Rapanos decision. Our primary purpose in issuing the guidance and associated technical field tools is to ensure a clear understanding of JD documentation requirements and foster a high level of national consistency in JD documentation and decisions. The guidance itself is not intended to either expand or contract CWA jurisdiction, but rather to effectively implement the decision by the Supreme Court in Rapanos.”

More Details

• June 2007 Legal Memorandum discussing Clean Water Act Jurisdiction Following the U.S. Supreme Court Decision in Rapanos v. United States & Carabell v. United States.
• June 2007 Memorandum of Agreement regarding coordination between EPA and Army Corps of Engineers on Jurisdictional Determinations.
• June 2007 Questions and Answers released by the EPA.