Technique for estimating magnitude and frequency of floods in Virginia

A technique is presented for estimating the magnitude and frequency of floods in Virginia. For 299 gaged sites, the magnitudes of floods having recurrence intervals of 2 to 100 years are provided in tables. For ungaged sites, regression relations are presented that allow the estimation of flood magnitudes based on upstream drainage area, average main-channel slope, and a factor to account for regional variations in basin terrain characteristics that would bias the results. A summary of maximum known peak discharges are presented for 363 sites together with the relationship of drainage-area size to flow in cubic feet per second per square mile. Also given is table of 10 basin characteristics for 403 gaging stations.