	Introduction

Streamgages measure water level and related streamflow at streams, rivers, lakes, and reservoirs across the country. Streamgages provide foundational information for diverse applications that affect a variety of constituents. These streamgages operate in every state, the District of Columbia, and the territories of Puerto Rico and Guam; therefore, national streamgage operations garner interest from many Members of Congress. Data fro m streamgages informs real-time decisionmaking and long-term planning on issues such as hazard preparations and response, infrastructure design, water use allocations, ecosystem management, and recreation. Direct users of streamgage data include a variety of agencies from all levels of government, utility companies, consulting firms, scientific institutions, and recreationists. In the United States, the U.S. Geological Survey (USGS), the Department of the Interior's (DOI's) lead scientific agency, manages the USGS Streamgaging Network ( Figure 1 ). The network encompasses 10,300 streamgages that record water height or streamflow for at least a portion of the year. Approximately 8,200 of these streamgages measure streamflow year-round and are part of the National Streamflow Network. Congressional appropriations and agreements with approximately 1,400 nonfederal partners funded the USGS Streamgaging Network at $189.5 million in FY2018. Interested parties sign funding agreements with the USGS to share the cost of streamgages and data collection. The USGS Cooperative Matching Funds Program (CMF) provides up to a 50% match with tribal, regional, state, and local partners (see section on " Cooperative Matching Funds Program "). A streamgage's primary purpose is to collect data on water levels and streamflow (the amount of water flowing through a river or stream over time). For example, the agency responded to over 670 million requests for streamflow and water level information in 2018. Water Science Research . Flood Mapping . Public and private entities may also elect to own and operate streamgages tailored to their specific needs and not affiliated with the USGS. Federal Priority Streamgages

The SECURE Water Act of 2009 (Title IX, Subtitle F of P.L. 111-11 ) directs the USGS to operate a reliable set of federally funded streamgages. Measuring flow for water quality needs. The USGS share included $24.7 million for FPSs and $29.8 million for CMF. Other federal agencies provided $40.7 million ( Table 1 ). Nonfederal partners, mostly affiliated with the CMF program, provided $94.3 million. While maintaining level funding for FPS and CMF streamgages in FY2019, Congress directed increased funding of $8.5 million for the deployment and operation of NextGen water observing equipment. For the entire USGS Streamgaging Network, the nonfederal cost-share contribution has increased from near 50% in the early 1990s to an average of about 63% in FY2018. The USGS and numerous stakeholders have raised funding considerations including user needs, priorities of partners, federal coverage, infrastructure repair, disaster response, inflation, and technological advances. Addressing the Size of the Network

The USGS uses appropriated funding to develop and maintain the USGS Streamgaging Network. While some stakeholders advocate for maintaining or expanding the network, others may argue that Congress should consider reducing the network in order to prioritize other activities. Congress mandated completion of a national network of no less than 4,700 streamgages in the SECURE Water Act of 2009. At the close of FY2018, 3,640 of the 4,760 FPSs designated by the USGS were operational, with 52% of their funding coming from the USGS. Modernizing the USGS Streamgaging Network

Congress might consider investments in new technologies for the USGS Streamgaging Network. Balancing Policy Options

Congress may consider outlining the future direction for the USGS Streamgaging Network through oversight or legislation. As the USGS faces a deadline by the SECURE Water Act of 2009 to operate no less than 4,700 FPSs by FY2019, Congress directed the USGS through appropriations legislation to invest in the NextGen system. Congress may consider pursuing both the FPS mandate and the NextGen system, amending the SECURE Water Act of 2009 to facilitate completion of FPSs, or replacing the FPS mandate with the Next Gen system.
Streamgages are fixed structures at streams, rivers, lakes, and reservoirs that measure water level and related streamflow—the amount of water flowing through a water body over time. The U.S. Geological Survey (USGS) in the Department of the Interior operates streamgages in every state, the District of Columbia, and the territories of Puerto Rico and Guam. The USGS Streamgaging Network encompasses 10,300 streamgages, which record water levels or streamflow for at least a portion of the year. Approximately 8,200 of these streamgages measure streamflow year round as part of the National Streamflow Network. The USGS also deploys temporary rapid deployment gages to measure water levels during storm events, and select streamgages measure water quality.
Streamgages provide foundational information for diverse applications that affect a variety of constituents. The USGS disseminates streamgage data free to the public and responds to over 670 million requests annually. Direct users of streamgage data include a variety of agencies at all levels of government, private companies, scientific institutions, and recreationists. Data from streamgages inform real-time decisionmaking and long-term planning on issues such as water management and energy development, infrastructure design, water compacts, water science research, flood mapping and forecasting, water quality, ecosystem management, and recreational safety.
Congress has provided the USGS with authority and appropriations to conduct surveys of streamflow since establishing the first hydrological survey in 1889. Many streamgages are operated cooperatively with nonfederal partners, who approach the USGS and sign joint-funding agreements to share the cost of streamgages and data collection. The USGS Cooperative Matching Funds (CMF) Program provides up to a 50% match with tribal, regional, state, and local partners, as authorized by 43 U.S.C. §50. The average nonfederal cost-share contribution has increased from 50% in the early 1990s to 63% in FY2018. In the early 2000s, the USGS designated federal priority streamgage (FPS) locations based on five identified national needs. The SECURE Water Act of 2009 (Title IX, Subtitle F, of P.L. 111-11) directed the USGS to operate by FY2019 no less than 4,700 federally funded streamgages. In FY2018, 3,640 of the 4,760 FPSs designated by the USGS were operational, with 52% of their funding from the USGS.
Congressional appropriations and agreements with 1,400 nonfederal partners funded USGS streamgages at $189.5 million in FY2018. The USGS share included $24.7 million for FPSs and $29.8 million for cooperative streamgages through CMF. A dozen other federal agencies provided $40.7 million. Nonfederal partners, mostly affiliated with CMF, provided $94.3 million. In FY2019, Congress appropriated level funding for FPS and CMF streamgages. Congress directed an additional $8.5 million to pilot a Next Generation Integrated Water Observing System (NextGen), establishing dense networks of streamgages in representative watersheds in order to model streamflow in analogous watersheds. The President's budget request for FY2020 does not include NextGen system funding and would reduce CMF for streamgages by $250,000.
The USGS uses appropriated funding to develop and maintain the USGS Streamgaging Network. The USGS and numerous stakeholders have raised funding considerations including user needs, priorities of partners, federal coverage, infrastructure repair, disaster response, inflation, and technological advances. Some stakeholders advocate for maintaining or expanding the network. Others may argue that Congress should consider reducing the network in order to prioritize other activities and that other entities operate streamgages tailored to localized needs. Congress might also consider whether to invest in streamgage restoration and new technologies.
Congress may consider outlining the future direction for the USGS Streamgaging Network through oversight or legislation. As the USGS faces a deadline by the SECURE Water Act of 2009 to operate no less than 4,700 FPSs by FY2019, Congress directed the USGS through appropriations legislation to invest in the NextGen system. Congress may consider such policy options as pursuing both the FPS mandate and the NextGen system simultaneously, amending the SECURE Water Act of 2009, and the relative emphasis of the NextGen system.