The Corps derives it regulatory authority over waters of the United States from the two Federal laws that are central to the Corps regulatory program. Section 10 of the Rivers and Harbors Act of 1899 applies to all navigable waters of the United States and Section 404 of the Clean Water Act applies to all waters including wetlands that have sufficient nexus to interstate commerce. Waters of the United States include essentially all surface waters such as all navigable waters and their tributaries, all interstate waters and their tributaries, all wetlands adjacent to these waters, and all impoundments of these waters.

In order to provide the most efficient service to the regulated community, the Honolulu District recommends that applicants hire a qualified environmental consultant to perform a delineation of aquatic resources. This applies to not only wetlands, but any feature that may fall under the definition of a water of the U.S. as described above. The Corps will then verify that the delineation is accurate and provide an approved jurisdictional determination. Jurisdictional determinations are generally valid for a period of five years, as site conditions and policies can change. An interested party can request an updated determination at any time.