This is an animation showing the changing conditions of USGS streamgages for Water Year 2018 (October 1, 2017 to September 30, 2018). The conditions shown range from the driest condition seen at a gage to the wettest.
As of October 2024, the USGS Groundwater and Streamflow Information Program supports the collection and (or) delivery of both streamflow and water-level information at 8,705 sites and water-level information alone at 3,460 additional sites. The data are served online—most in near real-time—to meet many diverse needs including the protection of life, property, the environment, and our economy.
Sources/Usage: Public Domain. View Media Details
In the late 1800s, John Wesley Powell, second Director of the U.S. Geological Survey (USGS), proposed gaging the flow of rivers and streams in the Western United States to evaluate the potential for irrigation. Around the same time, several cities in the Eastern United States established primitive streamgages for use in designing water-supply systems. Streamgaging technology has greatly advanced since the 1800s, and USGS hydrographers have made at least one streamflow measurement at more than 37,000 sites throughout the years. Today, the USGS Groundwater and Streamflow Information Program supports the collection and (or) delivery of both streamflow and water-level information at 8,705 sites (continuous record) and water-level information alone or partial record streamflow at 3,460 additional sites. The data are served online—most in near real-time—to meet many diverse needs; more than 2.5 billion requests for water information were fulfilled during the 2024 water year (Oct. 1, 2023‒Sept. 30, 2024).
Unique Partnership
The streamgages are primarily operated and maintained by the USGS, but most are funded in partnership with one or more of about 1,500 Federal, State, local, and Tribal agencies or organizations. This unique cooperation results in nationally consistent and impartial data that also aids local decision making. The shared costs result in the operation of far more streamgages than would be possible if financed solely by USGS appropriations, which provide less than one-third of the needed funding. These partnerships also enable fixed costs (such as costs associated with data storage and delivery infrastructure) to be broadly distributed, resulting in more economical streamgaging information for all.
“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
“Many thanks … we sincerely appreciate your [USGS] support. Your data makes our forecasts possible.”
Kevin Low, National Weather Service, Missouri River Basin Forecast Center Hydrologist, May 25, 2018
A Network of Networks
The USGS National Streamgaging Network (NSN) is a multipurpose network that comprises more than 12,165 streamgages. It encompasses several smaller networks that produce specific information or support specific needs.
National Streamgage Network–Streamflow (NSN-Streamflow). The National Streamgage Network-Streamflow (NSN) consists of all streamgages that continuously monitor streamflow year-round and from which daily mean streamflows are computed and made available online. The data collected at NSN-Streamflow locations serve several functions (including flood warning, water allocation, and recreation) and can be used by anyone regardless of whether or not they help fund the network. The use of consistent methods enables data from the many gages to be combined, expanding the use and value of the data from every gage. As of October 2024, there are 8,705 gages in the NSN-Streamflow.
Federal Priority Streamgages (FPS). The Federal Priority Streamgages (FPS) Network (previously known as the National Streamflow Information Program) was conceived in 1999 to be a core, federally funded network. The original network design included 4,300 then active, previously discontinued, or proposed new gages that were strategically positioned across the country to address long-term Federal information needs (such as supporting National Weather Service flood forecasts, or interstate and international compacts and decrees). As of October 2024, 4,756 locations meet the criteria for inclusion in the FPS network, but only 3,436 FPS are active because of funding limitations. These active FPS are supported through a combination of Federal and partner funding—but only 25-30 percent of the active FPS streamgages are fully funded by the USGS.
Information Delivery and Application
The USGS operates one of the largest streamgaging endeavors in the world. As of October 2024, continuous water levels were measured at 12,165 gages; the data are typically transmitted to USGS computers within 1 hour of measurement. During extreme events, data may be transmitted even more frequently. At most gages, continuously measured water levels are used to compute hourly (at least) time series of streamflows from gage-specific rating curves that were developed using onsite streamflow measurements made by USGS hydrographers—more than 80,000 onsite measurements are typically made each year. The data are quality assured and made available online. Data users include emergency responders, water managers, environmental and transportation agencies, universities, utilities, recreational enthusiasts, and consulting firms. Specific uses of the data include the following:
- planning, forecasting, and warning about floods and droughts;
- managing water rights and transboundary water issues;
- operating waterways for power production and navigation;
- monitoring environmental conditions to protect aquatic habitats;
- describing impacts to streamflow from changing land and water uses;
- assessing water quality and regulating pollutant discharges;
- determining if streams are safe for recreational activities; and
- designing reservoirs, roads, bridges, drinking water and wastewater facilities.
The user-friendly National Water Dashboard provides a map-based interface to access streamgaging data near you. You can also set thresholds important to you and get notified by email or text when your favorite streamgage reached that level by using the USGS WaterAlert application. All water data can be accessed at the USGS Water Data for the Nation webpages.
Below are other pages associated with the USGS streamgaging network.
Centennial Streamgages
Centennial Streamgages are USGS streamgages that have been in operation for more than 100 years.
USGS Streamgages By the Numbers
Get the facts and figures about the USGS Streamgaging Network, one of the largest streamgaging enterprises in the world!
Next Generation Water Observing System: Delaware River Basin
The USGS Next Generation Water Observing System (NGWOS) provides 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. The Delaware River Basin was the first NGWOS basin, providing an opportunity to implement the program in a nationally important, complex interstate...
Rapid Deployment Gages (RDGs)
Rapid Deployment Gages (RDGs) are fully-functional streamgages designed to be deployed quickly and temporarily to measure and transmit stream stage data in emergency situations.
StreamStats: Streamflow Statistics and Spatial Analysis Tools for Water-Resources Applications
StreamStats provides access to spatial analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. The map-based user interface can be used to delineate drainage areas, get basin characteristics and estimates of flow statistics, and more. Available information varies from state to state.
Streamgaging Basics
A streamgage is a structure installed beside a stream or river that contains equipment that measures and records the water level (called gage height or stage) of the stream. Streamflow (also called discharge) is computed from measured water levels using a site-specific relation (called a stage-discharge rating curve) developed from onsite water level and streamflow measurements made by USGS...
Federal Priority Streamgages (FPS)
Federal Priority Streamgages (FPS) are monitoring stations that track the amount of water in streams and rivers across the Nation and that meet one or more strategic, long-term Federal information needs. FPS are strategically positioned across the Nation to serve, in part, as a “backbone” of 4,756 eligible sites for the larger USGS streamgaging network of 11,885 sites (2023) that is operated by...
Surge, Wave, and Tide Hydrodynamics (SWaTH) Network
During large coastal storms, the storm surge and waves are the main cause of destruction and landscape change, transporting saline water, sediment, and debris inland. The USGS, in collaboration with stakeholders, has constructed a national Surge, Wave, and Tide Hydrodynamics (SWaTH) Network for the Atlantic, Eastern Pacific, and Central Pacific. SWaTH monitors and documents the height, extent, and...
Below are multimedia items associated with the USGS streamgaging network.
U.S. River Conditions for Water Year 2018
This is an animation showing the changing conditions of USGS streamgages for Water Year 2018 (October 1, 2017 to September 30, 2018). The conditions shown range from the driest condition seen at a gage to the wettest.
As of October 2024, the USGS Groundwater and Streamflow Information Program supports the collection and (or) delivery of both streamflow and water-level information at 8,705 sites and water-level information alone at 3,460 additional sites. The data are served online—most in near real-time—to meet many diverse needs including the protection of life, property, the environment, and our economy.
Sources/Usage: Public Domain. View Media Details
In the late 1800s, John Wesley Powell, second Director of the U.S. Geological Survey (USGS), proposed gaging the flow of rivers and streams in the Western United States to evaluate the potential for irrigation. Around the same time, several cities in the Eastern United States established primitive streamgages for use in designing water-supply systems. Streamgaging technology has greatly advanced since the 1800s, and USGS hydrographers have made at least one streamflow measurement at more than 37,000 sites throughout the years. Today, the USGS Groundwater and Streamflow Information Program supports the collection and (or) delivery of both streamflow and water-level information at 8,705 sites (continuous record) and water-level information alone or partial record streamflow at 3,460 additional sites. The data are served online—most in near real-time—to meet many diverse needs; more than 2.5 billion requests for water information were fulfilled during the 2024 water year (Oct. 1, 2023‒Sept. 30, 2024).
Unique Partnership
The streamgages are primarily operated and maintained by the USGS, but most are funded in partnership with one or more of about 1,500 Federal, State, local, and Tribal agencies or organizations. This unique cooperation results in nationally consistent and impartial data that also aids local decision making. The shared costs result in the operation of far more streamgages than would be possible if financed solely by USGS appropriations, which provide less than one-third of the needed funding. These partnerships also enable fixed costs (such as costs associated with data storage and delivery infrastructure) to be broadly distributed, resulting in more economical streamgaging information for all.
“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
“Many thanks … we sincerely appreciate your [USGS] support. Your data makes our forecasts possible.”
Kevin Low, National Weather Service, Missouri River Basin Forecast Center Hydrologist, May 25, 2018
A Network of Networks
The USGS National Streamgaging Network (NSN) is a multipurpose network that comprises more than 12,165 streamgages. It encompasses several smaller networks that produce specific information or support specific needs.
National Streamgage Network–Streamflow (NSN-Streamflow). The National Streamgage Network-Streamflow (NSN) consists of all streamgages that continuously monitor streamflow year-round and from which daily mean streamflows are computed and made available online. The data collected at NSN-Streamflow locations serve several functions (including flood warning, water allocation, and recreation) and can be used by anyone regardless of whether or not they help fund the network. The use of consistent methods enables data from the many gages to be combined, expanding the use and value of the data from every gage. As of October 2024, there are 8,705 gages in the NSN-Streamflow.
Federal Priority Streamgages (FPS). The Federal Priority Streamgages (FPS) Network (previously known as the National Streamflow Information Program) was conceived in 1999 to be a core, federally funded network. The original network design included 4,300 then active, previously discontinued, or proposed new gages that were strategically positioned across the country to address long-term Federal information needs (such as supporting National Weather Service flood forecasts, or interstate and international compacts and decrees). As of October 2024, 4,756 locations meet the criteria for inclusion in the FPS network, but only 3,436 FPS are active because of funding limitations. These active FPS are supported through a combination of Federal and partner funding—but only 25-30 percent of the active FPS streamgages are fully funded by the USGS.
Information Delivery and Application
The USGS operates one of the largest streamgaging endeavors in the world. As of October 2024, continuous water levels were measured at 12,165 gages; the data are typically transmitted to USGS computers within 1 hour of measurement. During extreme events, data may be transmitted even more frequently. At most gages, continuously measured water levels are used to compute hourly (at least) time series of streamflows from gage-specific rating curves that were developed using onsite streamflow measurements made by USGS hydrographers—more than 80,000 onsite measurements are typically made each year. The data are quality assured and made available online. Data users include emergency responders, water managers, environmental and transportation agencies, universities, utilities, recreational enthusiasts, and consulting firms. Specific uses of the data include the following:
- planning, forecasting, and warning about floods and droughts;
- managing water rights and transboundary water issues;
- operating waterways for power production and navigation;
- monitoring environmental conditions to protect aquatic habitats;
- describing impacts to streamflow from changing land and water uses;
- assessing water quality and regulating pollutant discharges;
- determining if streams are safe for recreational activities; and
- designing reservoirs, roads, bridges, drinking water and wastewater facilities.
The user-friendly National Water Dashboard provides a map-based interface to access streamgaging data near you. You can also set thresholds important to you and get notified by email or text when your favorite streamgage reached that level by using the USGS WaterAlert application. All water data can be accessed at the USGS Water Data for the Nation webpages.
Below are other pages associated with the USGS streamgaging network.
Centennial Streamgages
Centennial Streamgages are USGS streamgages that have been in operation for more than 100 years.
USGS Streamgages By the Numbers
Get the facts and figures about the USGS Streamgaging Network, one of the largest streamgaging enterprises in the world!
Next Generation Water Observing System: Delaware River Basin
The USGS Next Generation Water Observing System (NGWOS) provides 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. The Delaware River Basin was the first NGWOS basin, providing an opportunity to implement the program in a nationally important, complex interstate...
Rapid Deployment Gages (RDGs)
Rapid Deployment Gages (RDGs) are fully-functional streamgages designed to be deployed quickly and temporarily to measure and transmit stream stage data in emergency situations.
StreamStats: Streamflow Statistics and Spatial Analysis Tools for Water-Resources Applications
StreamStats provides access to spatial analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. The map-based user interface can be used to delineate drainage areas, get basin characteristics and estimates of flow statistics, and more. Available information varies from state to state.
Streamgaging Basics
A streamgage is a structure installed beside a stream or river that contains equipment that measures and records the water level (called gage height or stage) of the stream. Streamflow (also called discharge) is computed from measured water levels using a site-specific relation (called a stage-discharge rating curve) developed from onsite water level and streamflow measurements made by USGS...
Federal Priority Streamgages (FPS)
Federal Priority Streamgages (FPS) are monitoring stations that track the amount of water in streams and rivers across the Nation and that meet one or more strategic, long-term Federal information needs. FPS are strategically positioned across the Nation to serve, in part, as a “backbone” of 4,756 eligible sites for the larger USGS streamgaging network of 11,885 sites (2023) that is operated by...
Surge, Wave, and Tide Hydrodynamics (SWaTH) Network
During large coastal storms, the storm surge and waves are the main cause of destruction and landscape change, transporting saline water, sediment, and debris inland. The USGS, in collaboration with stakeholders, has constructed a national Surge, Wave, and Tide Hydrodynamics (SWaTH) Network for the Atlantic, Eastern Pacific, and Central Pacific. SWaTH monitors and documents the height, extent, and...
Below are multimedia items associated with the USGS streamgaging network.
U.S. River Conditions for Water Year 2018
This is an animation showing the changing conditions of USGS streamgages for Water Year 2018 (October 1, 2017 to September 30, 2018). The conditions shown range from the driest condition seen at a gage to the wettest.
This is an animation showing the changing conditions of USGS streamgages for Water Year 2018 (October 1, 2017 to September 30, 2018). The conditions shown range from the driest condition seen at a gage to the wettest.