Information on high-flow magnitude and frequency is needed for hydro-logic evaluation of such factors as flood-control storage and dam safety. High-flow information given in this report is for streamflows unaffected by major regulation, such as by large reservoirs. High-flow magnitude and frequency data are given for 91 streamflow-gaging stations through-out Kansas. Results of frequency calculations are given for durations of high flow of 1, 3, 7, 15, 30, 60, 90, 120, and 183 consecutive days. Accuracy of the magnitude-frequency values is influenced by the variability of flow, the number of years of flow record, and the recurrence interval calculated.
High-flow magnitude and frequency for ungaged sites can be estimated from regression equations using significant drainage-basin characteristics of contributing-drainage area; 50-year, 24-hour rainfall; and free-water-surface evaporation. Standard errors of estimate for ungaged sites on ungaged streams range from 31 to 49 percent, generally increasing with recurrence interval. If an ungaged site is near a gaging station having 10 or more years of record on the same stream, the data for the gaging station may be used to improve the regression estimates.