This document outlines the U.S. Army Corps of Engineers (USACE) processes and procedures for producing Annual Flood Damages Reduced (AFDR) data for Congressional reporting. It covers the background and purpose of AFDR, the selection of flood events, and methodologies for calculating AFDR using the Corps Water Management System (CWMS) across various watershed types.
The AFDR report, which is submitted to Congress as Appendix G, summarizes the annual benefits of federally funded Corps flood reduction projects. This report highlights the value of these projects and demonstrates the effectiveness of U.S. water resource investments, showing the return on investment. It also illustrates the "with vs. without project" impacts for specific storm events, revealing the often unseen benefits of Corps flood control efforts.
Generating AFDR data requires expertise in hydrology and hydraulics (H&H) modeling, a solid understanding of flood consequence economics, and close collaboration between specialists in these fields. This guide provides detailed methodologies and procedures for computing AFDR using CWMS.