This is a thumbnail for an animation showing the changing conditions relative to the historic record of USGS streamgages from October 1, 2023 - September 30, 2024. The river conditions shown range from the driest condition seen at a gage (red open circles) to the wettest (blue closed circles).
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.

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
"The near real-time data we get from the USGS Streamgage Network is essential to the South Dakota Flood Information System. Our system requires timely, accurate river level data to function correctly and the USGS streamgages have been a very reliable source."
Tim Cowman, State Geologist, South Dakota Geological Survey, January 2025
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-Streamflow) 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.
In the coming months, the results of the FPS Re-Prioritization will be updated here.
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.

Authorizations
USGS activities are conducted under the authority of various pieces of authorizing federal legislation. The following is a subset of authorizations that are related to the overall National Streamgaging Network:
43 U.S.C. § 36(b); § 50; § 50b | Appropriations Act (Pub. L. 118-42; Pub. L. 99-500; Pub. L. 77-842; Pub. L. 86-406)
Authorizes the implementation of the USGS Cooperative Matching Funds as they are used to partner with over 1,600 State, regional, and local agencies.
The Economy Act of 1932, as amended (31 U.S.C. 1535) authorizes any agency to obtain goods and services from and reimburse any other agency if certain criteria are met.
42 U.S.C. § 10367 - 10368 | Omnibus Public Land Management Act of 2009 (SECURE Water Act) (Pub. L. 111-11)
Authorizes (Title IX, Subtitle F, Sec. 9507 and 9508) the implementation of the national streamflow information program (more than 4,700 federal priority streamgages), development of a systematic groundwater monitoring program for each major aquifer system (the National Groundwater Monitoring Network), completion of a national brackish groundwater assessment, and implementation of the national water availability and use assessment program.
The subsequent reauthorization of the SECURE Water Act: Public Law 118-174.
43 U.S.C. § 36(b) | The Act of December 24, 1942, as amended (Pub. L. 86-406)
Provides that “The Secretary of the Interior may, on behalf of the United States and for the use by the Geological Survey in gaging streams and underground water resources, acquire lands by donation or when funds have been appropriated by Congress by purchase or condemnation” 36(c) Acceptance of contributions from public and private sources; cooperation with other agencies in prosecution of projects.
33 U.S.C. § 2352 | Water Resources Development Act of 2000 (Pub. L. 106-541)
Provides for the conservation and development of water and related resources. It authorizes the Secretary of the Army through the Assistant Secretary of the Army for Civil Works, to conduct studies, construct projects, and research activities that can lead to the improvement of rivers and harbors of the United States.
43 U.S.C. § 371 | Reclamation Projects Authorization and Adjustment Act of 1992, as amended (Pub. L. 104–46)
Amends the 1992 law to add Section 3001, "Western Water Policy Review Act of 1992." Directs the President to undertake a comprehensive review of Federal activities in the 19 western States that directly or indirectly affect the allocation and use of resources, whether surface or subsurface. The Secretary of the Interior, "... given … responsibilities for … investigations and reviews into ground water resources through the Geologic Survey (now United States Geological Survey).
25 U.S.C. § 450 et seq. | Tribal Self-Governance Act of 1994 (Pub. L. 103-413)
Requires that the Department of the Interior (DOI) publish an annual list of non-Bureau of Indian Affairs programs, services, functions, and activities, or portions thereof, that are eligible for inclusion in agreements negotiated under DOI’s self-governance program. The USGS mentions the collection, analysis, and provision information on biology, geology, hydrology, and geography that contribute to the wise management of the Nation’s natural resources and to the health, safety, and well-being of the American people.
16 U.S.C. § 797(a)(c) | Hydropower Regulatory Efficiency Act of 2013 (Pub. L. 113-23)
Authorizes Federal Energy Regulatory Commission investigations and data collection concerning the utilization of the water resources of any region to be developed (Section 797 (a)). Section 797(c) directs the FERC “to cooperate with the executive departments and other agencies of States or National Governments in such investigations; and for such purposes the several departments and agencies of the National Government are authorized and directed upon the request of the commission to furnish such records, papers, and information in their possession as may be requested by the commission, and temporarily to detail to the commission such officers or experts as may be necessary in such investigations.”
42 U.S.C. § 5845(c) | Energy Reorganization Act of 1974 (Pub. L. 93–438)
Directs all Federal agencies to “... (2)... furnish to the (Nuclear Regulatory) Commission... such research services... for the performance of its functions; and (3) consult and cooperate with the Commission on research development matters of mutual interest and provide such information and physical access to its facilities as will assist the Commission in acquiring the expertise necessary to perform its licensing and related regulatory functions.”
16 U.S.C. § 1451 et seq. | Coastal Zone Management Act of 1976 (Pub. L. 92–583)
Provides that each department, agency, and instrumentality of the Executive Branch of the Federal Government may assist the Secretary of Commerce, on a reimbursable basis or otherwise, in carrying out research and technical assistance for coastal zone management.
Here is a full list of Groundwater and Streamflow Information Program authorizations.
Below are other pages associated with the USGS streamgaging network.
National Water Monitoring Network
Centennial Streamgages
USGS Streamgages By the Numbers
Next Generation Water Observing System: Delaware River Basin
Rapid Deployment Gages (RDGs)
StreamStats: Streamflow Statistics and Spatial Analysis Tools for Water-Resources Applications
Streamgaging Basics
Federal Priority Streamgages (FPS)
Surge, Wave, and Tide Hydrodynamics (SWaTH) Network
Below are multimedia items associated with the USGS streamgaging network.
This is a thumbnail for an animation showing the changing conditions relative to the historic record of USGS streamgages from October 1, 2023 - September 30, 2024. The river conditions shown range from the driest condition seen at a gage (red open circles) to the wettest (blue closed circles).
The USGS collects water data daily across the U.S. using sensors that automatically sample the data at set intervals. We have over 11,000 of these devices, known as gages, in our nationwide network.
The data from these gages are used in decision-making at all levels, from recreationists to congresspersons.
The USGS collects water data daily across the U.S. using sensors that automatically sample the data at set intervals. We have over 11,000 of these devices, known as gages, in our nationwide network.
The data from these gages are used in decision-making at all levels, from recreationists to congresspersons.
The Water Data for the Nation team in USGS's Water Resources Mission Area has modernized our nationwide alert service: WaterAlert. With WaterAlert, you can subscribe to text or email alerts for recent water conditions that matter most to you.
The Water Data for the Nation team in USGS's Water Resources Mission Area has modernized our nationwide alert service: WaterAlert. With WaterAlert, you can subscribe to text or email alerts for recent water conditions that matter most to you.

What is water up to? Keeping the pulse on the Nation’s streams - USGS Streamgaging and the Groundwater and Streamflow Information Program.
What is water up to? Keeping the pulse on the Nation’s streams - USGS Streamgaging and the Groundwater and Streamflow Information Program.
Below are publications associated with the USGS streamgaging network.
Monitoring the pulse of our Nation's rivers and streams—The U.S. Geological Survey streamgaging network
The U.S. Geological Survey National Streamgage Network—2023
Discharge measurements at gaging stations
Below are data or web applications associated with the USGS streamgaging network.
National Water Dashboard (NWD)
WaterAlert
NWIS Current Water Data for the Nation (Real-Time Data)
USGS Flood Event Viewer
Federal Priority Streamgages (FPS) Mapper
Gages Through the Ages (data visualization story)
StreamStats Application
USGS Water Services
Endangered, Discontinued, and Rescued Streamgages Mapper
StreamStats Batch Processing Tool
StreamStats Web Services
Below are software products associated with this project.
National Streamflow Statistics (NSS) Application - Formerly NSS Program
The Groundwater Toolbox: A Graphical and Mapping Interface for Analysis of Hydrologic Data
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.

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
"The near real-time data we get from the USGS Streamgage Network is essential to the South Dakota Flood Information System. Our system requires timely, accurate river level data to function correctly and the USGS streamgages have been a very reliable source."
Tim Cowman, State Geologist, South Dakota Geological Survey, January 2025
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-Streamflow) 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.
In the coming months, the results of the FPS Re-Prioritization will be updated here.
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.

Authorizations
USGS activities are conducted under the authority of various pieces of authorizing federal legislation. The following is a subset of authorizations that are related to the overall National Streamgaging Network:
43 U.S.C. § 36(b); § 50; § 50b | Appropriations Act (Pub. L. 118-42; Pub. L. 99-500; Pub. L. 77-842; Pub. L. 86-406)
Authorizes the implementation of the USGS Cooperative Matching Funds as they are used to partner with over 1,600 State, regional, and local agencies.
The Economy Act of 1932, as amended (31 U.S.C. 1535) authorizes any agency to obtain goods and services from and reimburse any other agency if certain criteria are met.
42 U.S.C. § 10367 - 10368 | Omnibus Public Land Management Act of 2009 (SECURE Water Act) (Pub. L. 111-11)
Authorizes (Title IX, Subtitle F, Sec. 9507 and 9508) the implementation of the national streamflow information program (more than 4,700 federal priority streamgages), development of a systematic groundwater monitoring program for each major aquifer system (the National Groundwater Monitoring Network), completion of a national brackish groundwater assessment, and implementation of the national water availability and use assessment program.
The subsequent reauthorization of the SECURE Water Act: Public Law 118-174.
43 U.S.C. § 36(b) | The Act of December 24, 1942, as amended (Pub. L. 86-406)
Provides that “The Secretary of the Interior may, on behalf of the United States and for the use by the Geological Survey in gaging streams and underground water resources, acquire lands by donation or when funds have been appropriated by Congress by purchase or condemnation” 36(c) Acceptance of contributions from public and private sources; cooperation with other agencies in prosecution of projects.
33 U.S.C. § 2352 | Water Resources Development Act of 2000 (Pub. L. 106-541)
Provides for the conservation and development of water and related resources. It authorizes the Secretary of the Army through the Assistant Secretary of the Army for Civil Works, to conduct studies, construct projects, and research activities that can lead to the improvement of rivers and harbors of the United States.
43 U.S.C. § 371 | Reclamation Projects Authorization and Adjustment Act of 1992, as amended (Pub. L. 104–46)
Amends the 1992 law to add Section 3001, "Western Water Policy Review Act of 1992." Directs the President to undertake a comprehensive review of Federal activities in the 19 western States that directly or indirectly affect the allocation and use of resources, whether surface or subsurface. The Secretary of the Interior, "... given … responsibilities for … investigations and reviews into ground water resources through the Geologic Survey (now United States Geological Survey).
25 U.S.C. § 450 et seq. | Tribal Self-Governance Act of 1994 (Pub. L. 103-413)
Requires that the Department of the Interior (DOI) publish an annual list of non-Bureau of Indian Affairs programs, services, functions, and activities, or portions thereof, that are eligible for inclusion in agreements negotiated under DOI’s self-governance program. The USGS mentions the collection, analysis, and provision information on biology, geology, hydrology, and geography that contribute to the wise management of the Nation’s natural resources and to the health, safety, and well-being of the American people.
16 U.S.C. § 797(a)(c) | Hydropower Regulatory Efficiency Act of 2013 (Pub. L. 113-23)
Authorizes Federal Energy Regulatory Commission investigations and data collection concerning the utilization of the water resources of any region to be developed (Section 797 (a)). Section 797(c) directs the FERC “to cooperate with the executive departments and other agencies of States or National Governments in such investigations; and for such purposes the several departments and agencies of the National Government are authorized and directed upon the request of the commission to furnish such records, papers, and information in their possession as may be requested by the commission, and temporarily to detail to the commission such officers or experts as may be necessary in such investigations.”
42 U.S.C. § 5845(c) | Energy Reorganization Act of 1974 (Pub. L. 93–438)
Directs all Federal agencies to “... (2)... furnish to the (Nuclear Regulatory) Commission... such research services... for the performance of its functions; and (3) consult and cooperate with the Commission on research development matters of mutual interest and provide such information and physical access to its facilities as will assist the Commission in acquiring the expertise necessary to perform its licensing and related regulatory functions.”
16 U.S.C. § 1451 et seq. | Coastal Zone Management Act of 1976 (Pub. L. 92–583)
Provides that each department, agency, and instrumentality of the Executive Branch of the Federal Government may assist the Secretary of Commerce, on a reimbursable basis or otherwise, in carrying out research and technical assistance for coastal zone management.
Here is a full list of Groundwater and Streamflow Information Program authorizations.
Below are other pages associated with the USGS streamgaging network.
National Water Monitoring Network
Centennial Streamgages
USGS Streamgages By the Numbers
Next Generation Water Observing System: Delaware River Basin
Rapid Deployment Gages (RDGs)
StreamStats: Streamflow Statistics and Spatial Analysis Tools for Water-Resources Applications
Streamgaging Basics
Federal Priority Streamgages (FPS)
Surge, Wave, and Tide Hydrodynamics (SWaTH) Network
Below are multimedia items associated with the USGS streamgaging network.
This is a thumbnail for an animation showing the changing conditions relative to the historic record of USGS streamgages from October 1, 2023 - September 30, 2024. The river conditions shown range from the driest condition seen at a gage (red open circles) to the wettest (blue closed circles).
This is a thumbnail for an animation showing the changing conditions relative to the historic record of USGS streamgages from October 1, 2023 - September 30, 2024. The river conditions shown range from the driest condition seen at a gage (red open circles) to the wettest (blue closed circles).
The USGS collects water data daily across the U.S. using sensors that automatically sample the data at set intervals. We have over 11,000 of these devices, known as gages, in our nationwide network.
The data from these gages are used in decision-making at all levels, from recreationists to congresspersons.
The USGS collects water data daily across the U.S. using sensors that automatically sample the data at set intervals. We have over 11,000 of these devices, known as gages, in our nationwide network.
The data from these gages are used in decision-making at all levels, from recreationists to congresspersons.
The Water Data for the Nation team in USGS's Water Resources Mission Area has modernized our nationwide alert service: WaterAlert. With WaterAlert, you can subscribe to text or email alerts for recent water conditions that matter most to you.
The Water Data for the Nation team in USGS's Water Resources Mission Area has modernized our nationwide alert service: WaterAlert. With WaterAlert, you can subscribe to text or email alerts for recent water conditions that matter most to you.

What is water up to? Keeping the pulse on the Nation’s streams - USGS Streamgaging and the Groundwater and Streamflow Information Program.
What is water up to? Keeping the pulse on the Nation’s streams - USGS Streamgaging and the Groundwater and Streamflow Information Program.
Below are publications associated with the USGS streamgaging network.
Monitoring the pulse of our Nation's rivers and streams—The U.S. Geological Survey streamgaging network
The U.S. Geological Survey National Streamgage Network—2023
Discharge measurements at gaging stations
Below are data or web applications associated with the USGS streamgaging network.
National Water Dashboard (NWD)
WaterAlert
NWIS Current Water Data for the Nation (Real-Time Data)
USGS Flood Event Viewer
Federal Priority Streamgages (FPS) Mapper
Gages Through the Ages (data visualization story)
StreamStats Application
USGS Water Services
Endangered, Discontinued, and Rescued Streamgages Mapper
StreamStats Batch Processing Tool
StreamStats Web Services
Below are software products associated with this project.