Alaska Science Center
AK Streamflow StatisticsAK Streamflow Statistics Home
Flow duration and low-flow frequency
Streamflow Record Extension
Alaska Streamflow Statistics
Streamflow statistics are periodically computed by the USGS for data collected at streamflow-gaging stations. Common streamflow statistics include streamflow frequency (such as the 1-percent chance flood, also known as the 100-yr flood) and flow-duration statistics (such as the 98-percent duration flow). Data for USGS streamflow data-collection stations in Alaska are available at NWISWeb.
Equations are developed from streamflow statistics together with physical or climatic characteristics of drainage areas for a group of sites with streamgages. The equations can be applied to estimating streamflow statistics at ungaged sites. These estimates are used by water resource planners and managers for designing infrastructure, managing floodplains, and protecting life, property, and aquatic resources.
Methods for accessing data and estimating streamflow statistics for Alaska are provided in USGS reports and are available for selected locations in StreamStats, an online tool that facilitates access to streamflow information and computation tools.
Alaska Streamflow Statistics Studies
The most recent studies of streamflow statistics for Alaska include reports on flood frequency, flow duration, low-flow frequency, and streamflow record extension. Tools and examples are provided for estimating streamflow statistics for ungaged sites.