TVA Practice in Flood Frequency and Risk Analysis

Abstract

The Tennessee Valley Authority (TVA) is a government corporation established in 1933 with broad regional resource development responsibilities. In carrying out its responsibilities TVA has constructed dams and fossil and nuclear power plants, operates and maintains its dams including their safety evaluation, and maintains a program of floodplain management activities with communities, industries, and individuals. This paper describes the flood frequency and risk analysis procedures used by TVA in these activities. Discussed are (1) TVA’s conclusions about the most accurate methods to compute flood frequency at ungaged locations including use of limited site historic flood data obtained through TVA’s flood documenting activities, (2) the procedures and data used by TVA to estimate the PMF to ensure estimates are realistic and compatible with meteorological experience, (3) approaches TVA has used to define flood frequencies of extreme events up to and including the PMF, and (4) risk analysis as applied by TVA in community planning and dam safety evaluations. Recommendations as to additional procedures needed to enhance the engineer’s capability for improved flood frequency and risk analysis are made.