The U.S. House Government Oversight Committee and U.S. House Transportation and Infrastructure Committee released a memorandum that highlights the threat to the nation’s waters posed by the Supreme Court decision Rapanos v. United States (2006), which has created legal confusion about what waters are protected by the Clean Water Act. The decision concerned protection of wetlands next to non-navigable tributaries of navigable waters. A letter to President Barack Obama accompanying the memorandum concludes, “the federal government’s Clean Water Act enforcement program has been decimated over the last two years, imperiling the health and safety of the nation’s waters.”

In response to the legal confusion, the U.S. Environmental Protection Agency, Washington, D.C., and U.S. Army Corps of Engineers, Washington, released a revised guidance to field officials instructing them how to assert Clean Water Act jurisdiction over wetlands, streams and other waters. The revised guidance makes three primary changes. In many cases, it requires waters to support or be capable of supporting commercial activity so the water can be considered “traditionally navigable,” allowing it to be protected by the act. Currently and under case law, mere navigation or susceptibility to navigation, including recreational navigation, suffices. A second change attempts to clarify when a wetland is adjacent to another water body. The final change states that tributary flow now can be measured as the flow regime that best characterizes the entire tributary. For more information about the Clean Water Act, visit watertrain/cwa.