100 Year Flood (Base Flood) : A flood that has a 1 percent chance of occurring in any given year. A 500 Year Flood has 0.2 percent chance of occurring in any given year
Robert E. Chapman and Douglas S. Thomas, A Guide to Printed and Electronic Resources for Developing a Cost-Effective Risk Mitigation Plan for New and Existing Constructed Facilities, Glossary of Related Terms & Acronyms and Abbreviations, U.S. Department of Commerce Technology Administration National Institute of Standards and Technology, Office of Applied Economics Building and Fire Research Laboratory (NISTIR 7390), MD, USA 2007. http://fire.nist.gov/bfrlpubs/build07/PDF/b07011.p df, (Rsk Anlys and Mgt Procss - Amer) {986}