Flood Frequency Data Collection for Alaska and Conterminous Drainage Basins in Canada

Estimates of the magnitude and frequency of floods are needed for engineering design of transportation and water-conveyance structures, flood-insurance studies, flood-plain management, and other water-resource purposes. In 2016, the U.S. Geological Survey estimated flood frequency and magnitude for selected streamgages in Alaska and conterminous basins in Canada and developed methods for estimating flood frequency and magnitude at ungaged streams (Curran and others, 2016). More current estimates of flood frequency are often needed for water-resource purposes, including estimating the annual exceedance probability of an observed flood peak.