Geographically Isolated Wetlands: Why We Should Keep the Term

Abstract

Use of the term “isolated wetlands” in the U.S. Supreme Court’s SWANCC decision created confusion, since it could imply functional isolation. In response, the term “geographically isolated wetlands” (GIWs) – wetlands surrounded by uplands – was introduced in 2003. A recent article revisits the term, concluding that it is a misnomer that adds to the confusion. Hydrogeomorphic (HGM) type and non-adjacency to jurisdictional waters are suggested as alternatives. To address this issue, I pose two questions: is there a need to identify wetlands surrounded by uplands and what to call them? Regarding the former, there is a legal/regulatory need resulting from the Court’s Rapanos decision: to help determine whether such wetlands have a significant nexus with traditional navigable waters. There is also a scientific need to understand how the normal lack of surface water connectivity affects function. Regarding the second question, neither HGM type nor non-adjacency adequately identifies wetlands surrounded by uplands. I contend that “GIW” remains the most informative option. However, the term needs to be applied properly and researchers should emphasize that being surrounded by uplands does not imply hydrological or biological isolation. Further, conclusions from one GIW type should be extrapolated to other GIWs with great care.