Magnitude and frequency of floods in small drainage basins in North Dakota

This report describes methods for estimating flood-peak discharges having 2- to 50-year recurrence intervals on North Dakota streams draining less than 100 square miles ( 259 square kilometres). For gaged sites, frequency estimates are provided directly. For ungaged sites, flood peaks are estimated from multiple-regression equations using drainage-area size and, in two regions, soil-infiltration index as estimating variables.  Nomographs provide simple solutions for the equations for flood-peak discharges having recurrence intervals of 10, 25, and 50 years. The methods described are not applicable to streams draining urban areas or basins affected by man-made regulation.  

Information is also provided on the maximum flood magnitude experienced.