Supporting Data for Estimating Selected Low-Flow Frequency Statistics and Mean Annual Flow for Ungaged Locations on Streams in Alabama (ver. 1.1, November 2020)

Streamflow data and statistics are vitally important for proper protection and management of both the water quality and water quantity of Alabama streams. Such data and statistics are available at U.S. Geological Survey streamflow-gaging stations, also referred to as streamgages or stations, but are often needed at ungaged stream locations. To address this need, the U.S. Geological Survey, in cooperation with numerous Alabama State agencies and organizations, developed regional regression equations for estimating selected low-flow frequency statistics and mean annual flow for ungaged locations in Alabama that are not substantially affected by tides, regulation, diversions, or other anthropogenic influences. This data release comprises the geographic information systems (GIS) layers and tabular data used to create the new low-flow and mean annual flow regression equations and implement them for the U.S. Geological Survey StreamStats application (https://streamstats.usgs.gov).