Floods of June 1965 in Arkansas River basin, Colorado, Kansas, and New Mexico

Maximum discharges during the floods of June 1965 in the Arkansas River basin in Colorado, Kansas, and New Mexico were greater than those previously known at 49 of the 137 locations where flood information was obtained. Property damage exceeded $60 million, and 16 lives were lost. At many sites, peak discharges exceeded by severalfold the discharges that may be expected, on the average, once in 50 years; yet, the 1965 discharges could be exceeded in the near future.

Heavy rainfall of more than 12 inches in several areas and more than 18 inches near Two Buttes, Colo., caused severe flooding in the Arkansas River basin in Colorado and Kansas and the Canadian River basin in New Mexico. Snowmelt runoff added only token amounts to the flood peaks. The 1965 peak discharges along the main stem of the Arkansas River in Colorado were less than those in 1921, but tributary peaks were probably greater at many sites In New Mexico the peak discharges exceeded those for the destructive floods of 1904 at some locations, by manyfold at some sites.

Descriptions of the storms and floods, detailed streamflow records, and information on
damages and flood frequency are included in this report. Comparisons of the magnitude of the floods are made, and all indicate that an outstanding hydrologic event occurred.