The U.S. Army Corps of Engineers, Honolulu District Regulatory Office (Corps) announces the availability of the Coral Ecological Services and Functions Assessment Tool (CAT) for the state of Hawaii. The Corps Regulatory Program involves the regulation of discharges of dredged or fill material into waters of the United States (WOTUS) and structures or work in navigable waters of the United States, under Section 404 of the Clean Water Act and Section 10 of the Rivers and Harbors Act of 1899, respectively. Activities in waters of the U.S. that require a Corps permit include the incorporation and implementation of avoidance, minimization, and mitigation measures intended to reduce adverse environmental impacts resulting from the proposed activity. For unavoidable impacts, compensatory mitigation may be required to offset the loss of waters of the U.S., special aquatic sites and/or other aquatic resource functions. For projects that impact corals, the CAT would assist the Corps in determining the appropriate form and amount of compensatory mitigation required.