Kernell G. Ries

Stream-Network Navigation in the U.S. Geological Survey StreamStats Web Application

StreamStats is a U.S. Geological Survey Web-based geographic information systems application developed as a tool for water-resources planning and management, engineering design, and other applications. The primary functionality of StreamStats allows users to obtain drainage-basin boundaries, basin characteristics, and streamflow statistics for gaged and ungaged sites. Recently, tools that allow stream-network navigation were added to StreamStats. These tools allow users to select any point along a stream and locate activities upstream and downstream from the selected point, such as streamgaging stations, dams, and point-source discharges, and obtain information about such activities. Users also can obtain stream-reach addresses and estimates of streamflow statistics for the selected points.

Use of the StreamStats Web Application for TMDL Analysis

StreamStats (http://streamstats.usgs.gov) is a U.S. Geological Survey (USGS) Web-based geographic information systems application developed as a tool for water-resources planning and management, engineering design, and numerous other applications, and is a useful tool for analyzing Total Maximum Daily Loads (TMDLs). StreamStats users can select data-collection station locations shown on an interactive map interface to obtain previously published streamflow statistics, basin characteristics, and descriptive information for the stations. Users also can select any location along a stream to obtain the drainage-basin boundary, basin and climatic characteristics, and streamflow statistics for the location, estimated based on either regional regression equations or on the flow per unit drainage area for the statistics at nearby streamgaging stations. These estimates of streamflow statistics can be useful for TMDL analysis. For example, StreamStats applications for several states provide estimates of 7-day, 10-year low flows, which are used by many states for permitting of effluent discharges.

Identifying a base network of federally funded streamgaging stations

The U.S. Geological Survey (USGS) has completed a preliminary analysis to identify streamgaging stations needed in a base network that would satisfy five primary Federal goals for collecting streamflow information. The five goals are (1) determining streamflow at interstate and international borders and at locations mandated by court decrees, (2) determining the streamflow component of water budgets for the major river basins of the Nation, (3) providing real-time streamflow information to the U.S. National Weather Service to support flood-forecasting activities, (4) providing streamflow information at locations of monitoring stations included in USGS national water-quality networks, and (5) providing streamflow information necessary for regionalization of streamflow characteristics and assessing potential long-term trends in streamflow associated with changes in climate. The analysis was done using a Geographic Information System. USGS headquarters staff made initial selections of stations that satisfied at least one of the five goals, and then staff in each of the 48 USGS district offices reviewed the selections, making suggestions for additions or changes based on detailed local knowledge of the streams in the area. The analysis indicated that 4,242 streamgaging stations are needed in the base network to meet the 5 Federal goals for streamflow information. Of these, 2,692 stations (63.5 percent) are currently operated by the USGS, 277 stations (6.5 percent) are currently operated by other agencies, 865 (20.4 percent) are discontinued USGS stations that need to be reactivated, and 408 (9.6 percent) are locations where new stations are needed.