StreamStats is a Web-based Geographic Information Systems (GIS) application that provides users with access to an assortment of analytical tools that are useful for a variety of water-resources planning and management purposes, and for engineering and design purposes. StreamStats users can select United States Geological Survey (USGS) data-collection station locations shown on a map and obtain previously published information for the stations. Users also can select any location along a stream and obtain the drainage-basin boundary, basin characteristics, and estimates of streamflow statistics for the location. The streamflow statistics that StreamStats can provide for data-collection stations and for user-selected ungaged sites vary among the implemented states and among data-collection stations within states.

The StreamStats home page provides links to a more detailed description of the program, a user's manual, descriptions of the outputs, definitions of basin characteristics and streamflow statistics, limitations for use of the application, and other information. The user's manual also can be accessed by clicking on the Help link on the user interface. Users should read the user's manual before attempting to use the application. 

StreamStats provides estimates of various streamflow statistics for user-selected sites by solving regression equations. The regression equations were developed through a process, known as regionalization, which involves use of regression analysis to relate streamflow statistics computed for a group of selected streamgages (usually within a state) to basin characteristics measured for the streamgages. Basin characteristics measured by StreamStats are entered into the resulting equations to obtain estimates of the streamflow statistics for ungaged sites. The regression equations generally were developed separately for each state through cost-sharing agreements between the USGS and state agencies. As a result, the equations that are available for a given state vary based on which statistics the state agencies need for regulatory, planning, or other purposes. After first selecting a state of interest in the user interface, the State/Regional Info tab above describes the streamflow statistics that can be estimated using regression equations for locations within the selected state. This tab also describes any special functionality that is available or issues with using StreamStats for the state, it provides links to related reports, and it identifies the cooperating agencies that supported StreamStats implementation.

The map below indicates the status of StreamStats nationally. Green states are available with full functionality. Purple states allow basin delineations and computing basin characteristics, but estimates of flow statistics from regression equations are not available. Blue states are currently in development. Yellow states are not implemented because no other agency has agreed to partner with the USGS to cover implementation costs.

Several tools are in development that will rely on searching along the stream network upstream or downstream from user-selected sites to identify stream reaches and water-related activities along the streams, such as dams and point discharges, and obtain information about those activities. In addition, users will be able to obtain elevation profiles along stream channels and between points on the land surface.

The U.S. Geological Survey StreamStats interface was developed in cooperation with many agency (federal, state, and local) partners by the Web Informatics and Mapping (WiM) group in collaboration with the USGS Office of Surface Water StreamStats team, working with USGS Water Science Centers across the nation. USGS thanks the cooperators and collaborators that have helped to make full or partial implementation of StreamStats possible within their states and regions.