Floods in Wyoming, magnitude and frequency

This report contains the results of four separate flood-frequency analyses designated A, B, C, and D. Analysis A is for the portion of Wyoming east of the Continental Divide. Analysis B applies to the portion of Wyoming in Part 9, as designated in streamflow reports entitled "Surface Water Supply of the United Stated" published by the U.S. Geological Survey, and was extracted fro.m an unpublished study by W. P. Somers in 1959. Analysis C applies to Part 10 and was extracted from Circutar 457 (Berwick, 1962). Analysis D applies to Part 13 and was extracted from a report by C. A. Thomas, H. C. Broom, and J. E. Cummans (1963).

Methods described in this report can be used to estimate the magnitude of a flood of any selected recurrence interval between 1.1 and 50 years for any unregulated stream in Wyoming, gaged or ungaged, within the scope of the data. Flood-frequency relations are not defined for a large part of the North Platte River basin in south-central Wyoming because of insufficient data.