Magnitude and frequency of floods in eastern Oregon

A method for estimating the magnitude and frequency of floods is presented for unregulated streams in eastern Oregon. Equations relating flood magnitude to basin characteristics were developed for exceedance probabilities of 0.5 to 0.01 (2- to 100-year recurrence intervals). Separate equations are presented for four regions: Southeast, Northeast, North Central, and Eastern Cascades. Also presented are values of flood discharges for selected exceedance probabilities and of basin characteristics for all gaging stations used in the analysis. Included are data for 148 stations in Oregon, 3 stations in northern California, 3 stations in western Idaho, 4 stations in northern Nevada, and 4 stations in southern Washington. Drainage areas used in the analysis range from 0.47 to 11,300 square miles. Also included are maximum discharges for all eastern Oregon stations used in the analysis. (USGS)