Storm Loss Rates for Regions with Limited Data

For regions with limited data, storm loss rates for use in design flood estimation must be based on derived values from other regions. Reference is made to a large body of published loss rate data for Australia and New Zealand. With available United States data, these values greatly extend the conditions for which computed loss rate data are available. All loss rate values, and watershed median and minimum values, are compared for the three countries. In each case, the frequency distributions of values are similar. Most loss rates for each of the countries have low values, more than one half being equal to or less than 0.10 in. per hr. A consistent seasonal trend is also revealed with a tendency to lower values in winter and higher values in summer. The comparisons of the sets of data lend strong, but not conclusive, support to the validity of transferring loss rates from a region with adequate data to another with limited data.