This report presents a method of determining the magnitude and frequency of floods that can be expected in New Mexico The discharge of the mean annual flood for various regions in the State is defined. Curves relate mean annual flood and drainage area. Drainage area was the only basin characteristic found to have an appreciable effect on discharge of the mean annual flood except in two regions where a relation with altitude also is defined. Composite frequency curves relate discharge of the mean annual flood to the discharge of floods having recurrence intervals from 1.1 to 50 years. These relationships are based on records 5 or more years in length from gaging stations that had flow essentially unregulated.