Groundwater and Streamflow Information Program

Streamflow monitoring

USGS Streamgaging

USGS Streamgaging

The USGS operates a multipurpose streamgaging network that includes more than 10,000 streamgages and meets many diverse needs.

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Next Generation Water Observing System

Next Generation Water Observing System

The NGWOS will provide quantitative info on streamflow, evapotranspiration, snowpack, soil moisture, water quality, groundwater / surface water connections, and water use.

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The USGS works in partnership with more than 1,400 Federal, regional, State, Tribal, and local agencies or organizations to maintain and manage a multipurpose network of streamgages that monitor streamflow and (or) water level. Approximately 8,200 of the more than 10,000 USGS streamgages in the network continuously monitor streamflow year-round and are collectively referred to as the National ‘Streamflow’ Network (NSN). Approximately 40% of the NSN is made up of Federal Priority Streamgages (FPS), which are considered critical for long-term tracking and modeling/forecasting to ensure that Federal water priorities and responsibilities can be met. Such priorities and responsibilities include forecasting hydrologic events (floods and droughts); managing interstate agreements, compacts, court decrees, and other legal obligations; and tracking streamflow in major river basins and across borders. USGS streamgage data are made available online and are used by governmental organizations, private industries, and the general public. The data form the scientific basis for decision making related to protection of life and property from water-related hazards, such as floods; cost-effective management of freshwater that is safe and available for drinking, irrigation, energy, industry, recreation, and ecosystem health; and national, State, Tribal, and local economic well-being. In addition to maintaining and managing a national network of streamgages, the GWSIP ensures the integrity and quality of the data and information produced by its streamflow monitoring program by investing in quality assurance, and research and development.

Highlights

Below, please find several highlights of recent streamflow monitoring accomplishments and planned activities.

  • In 2018, approximately 3,600 of the targeted 4,760 FPS sites were operational and 3,460 provided near real-time data to the public;1,264 were fully funded by the GWSIP (FPS Base Funds) and the other 2,336 were jointly funded by the GWSIP (FPS Base Funds or Cooperative Matching Funds) and USGS partners. Total FPS base funding for these streamgages was $24.7 million.​
  • There were 946 million page requests from NWISWeb and another 896 million requests for USGS gage data through web services during 2018. While these statistics represent all data (surface water, groundwater, water quality, water use) that are accessible, over 75% of these data requests were made to streamgage real-time data pages. These data are used for a variety of activities, such as managing flood or water scarcity risk to humans, designing bridges, roads and water-treatment plants, and supporting freshwater biodiversity conservation.
  • In 2018, published revision to Guidelines for Determining Flood Flow Frequency--Bulletin 17C.
  • In 2018, published analysis of the spatial and temporal variability in the frequency, duration, and severity of hydrological droughts across the conterminous United States (CONUS).
  • In 2018, the USGS responded to Hurricane Florence and worked closely with the National Weather Service, Federal Emergency Management Agency, State Emergency Management Divisions and Department of Transportations, U.S. Army Corps of Engineers, and local law enforcement to provide information needed to inform response decisions related to the hurricane. USGS installed 32 rapid deployment gages, 160 storm-tide sensors, flagged over 300 high-water marks (access and download the data) and have made more than 140 high-flow streamflow measurements to provide information vital to people making decisions about public safety.
  • In 2018, the USGS selected the Delaware River Basin as a pilot for implementing the Nation’s next-generation (NextGen) integrated water observing system to provide high-fidelity, real-time data on water quantity and quality necessary to support modern water prediction and decision support systems for water emergencies and daily water operations.
  • In 2018, several alternative streamflow measurement methods and equipment were evaluated in Alaska, Arizona, Colorado, and Idaho including thermal video, hyperspectral imaging, LiDAR, and other low cost, streamflow methods.
  • In 2017, the USGS re-established a streamgage and added water-quality monitoring at the Unuk River, a river that is critical to tribal fisheries and serves as an important natural resource for Southeast Alaska fishing and tourism industries.

Stakeholder Quotes

“The independent, science-based streamflow information that we obtain from USGS gages is paramount to assuring compliance under our various interstate compacts with our neighboring states.”
Julie Cunningham, Oklahoma Water Resources Board

“I wanted to thank your team for their stellar work yesterday moving/installing new instruments at both dams [Barker and Addicks reservoirs]. It allows us to continue to use our assets and monitoring systems of the dams in the way we intended, allowing us to do more intensive monitoring elsewhere. The professionalism and skill your team displayed should make all taxpayers proud. Truly above and beyond.”
Coraggio Maglio, P.E., U.S. Army Corps of Engineers Galveston District