Accurate
estimates of flood frequency and magnitude are a key component of any effective
nationwide flood risk management and flood damage abatement program. In
addition to accuracy, methods for estimating flood risk must be uniformly and
consistently applied because management of the nation’s water and related land
resources is a collaborative effort involving multiple actors, including most
levels of government and the private sector. Bulletin 17C’s Chapter B5 of book 4 (TM 4–B5) deals with flood flow frequency analysis at gaged
sites using the Expected Moments Algorithm. The use of extreme flood data
represented by interval and censored data types, including historical,
paleoflood and botanical evidence, is emphasized.