By Robert E. Holden and Monica Derbes Gibson


The Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers have released long-awaited guidance addressing jurisdictional determinations under the Clean Water Act (CWA) in the wake of Rapanos v. United States, 126 S. Ct. 2208 (2006).  There is general agreement that Rapanos limited the reach of the CWA, but the Court did not articulate a clear standard for determining whether or not a wetland or body of water is covered by the CWA.  In the guidance, EPA and the Corps explain how they will approach jurisdictional determinations in light of the Rapanos decision.  Click here to view the guidance.  The agencies will take public comments on implementation of the guidance until December 5, 2007.  Comments may be submitted online at, to Docket No. EPA-HQ-OW-2007-0282, or by email to, with the docket number in the “subject” line. 

In 2006, the Supreme Court decided two consolidated cases involving the Corps’ authority to require dredge and fill permits under CWA § 404 for discharge into wetlands having only indirect connections to navigable waters.  Rapanos v. United States, and Carabell v. United States, 126 S. Ct. 2208 (2006).  The Corps had asserted jurisdiction over the wetlands as "adjacent wetlands" under 33 C.F.R. § 328.3(a)(7), the definition of "waters of the United States," and the property owners objected.  The Supreme Court issued five separate opinions:  one plurality opinion, two concurring opinions, and two dissenting opinions.  The plurality opinion stated that “adjacent wetlands” of “waters of the United States” must have a continuous surface connection to a “water of the United States” and that the “water of the United States” must be a relatively permanent body of water connected to traditional interstate navigable waters.  In a concurring opinion, Justice Kennedy set out a different test:  that in order to fall within CWA jurisdiction, an “adjacent wetland” must have a “significant nexus” to traditionally navigable waters.  Because the Court did not agree on a single standard, Rapanos has made it more confusing to ascertain whether a wetland or non-navigable waterway is under the jurisdiction of the CWA. 


In an effort to resolve some of the confusion, the Corps and EPA have developed and issued guidance to EPA regions and Corps districts charged with implementing Rapanos.  U.S. EPA and U.S. Army Corps of Engineers, Clean Water Act Jurisdiction Following the U.S. Supreme Court’s Decision in Rapanos v. United States & Carabell v. United States, June 8, 2007.  The guidance observes that “[w]here there is no majority opinion in a Supreme Court case, controlling legal principles may be derived from those principles espoused by five or more justices.”  Guidance at 2.  Under this approach, “regulatory jurisdiction under the CWA exists over a water body if either the plurality’s or Justice Kennedy’s standard is satisfied.”  Id. 


The agencies will continue to assert jurisdiction over traditional “navigable waters”:  waters that are currently used, or have been used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters that are subject to the ebb and flow of the tide.  Guidance at 4-5.  Also, wetlands adjacent to traditional navigable waters will be subject to EPA and Corps jurisdiction.  Id. at 5.  Regulations of EPA and the Corps define “adjacent” as “bordering, contiguous, or neighboring.”  According to the guidance, “Rapanos does not affect CWA jurisdiction over wetlands that are adjacent to traditional navigable waters because at least five justices agreed that such wetlands are ‘waters of the United States.’”  Id.


A second category of waters, non-navigable tributaries of navigable waters, is subject to CWA jurisdiction when the tributary is “relatively permanent.”  Id.  Tributaries that ordinarily flow year-round or that have at least a continuous seasonal flow would be considered “relatively permanent.”  Id. at 6.  Tributaries that flow only in connection with precipitation events and intermittent streams that do not flow year-round or have continuous seasonal flow would not be considered “relatively permanent.”  Id.  Adjacent wetlands having a continuous surface connection with a relatively permanent, non-navigable tributary are subject to CWA jurisdiction.  Id. 


Finally, the agencies will perform case by case analyses to determine whether the following types of waters 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; and

·        wetlands adjacent to, but not directly abutting a relatively permanent tributary (e.g., separated from the tributary by uplands or a berm, dike, or other similar feature).

Id. at 7.  The “significant nexus” analysis will consider hydrologic and ecologic factors to determine whether the wetland or non-navigable tributary significantly affects the chemical, physical, and biological integrity of the traditional navigable water.  Id.   The guidance states that swales or erosional features such as gullies generally would not be considered “waters of the United States.”  Id. at 11.  Also, ditches that are located in uplands and that do not carry a relatively permanent flow of water generally are not “waters of the United States.”  Id.  However, even if a gully or ditch does not have a significant nexus with a navigable water, the tributary may be considered a point source discharging pollutants into the navigable water, and therefore may be under CWA jurisdiction.  Id.