S. 1626 — National Landslide Preparedness Act Reauthorization Act of 2025

This section adds definitions to the NOAA Precipitation Frequency Atlas of the United States program—(1) "atmospheric river" (i.e., a transient corridor of strong water vapor producing significant rain or snow that may benefit water supply or cause flooding); (2) "atmospheric river flooding event" (i.e., such an event resulting in river flooding or hazards of concern to health, property, and the economy, as determined by the Secretary of Commerce); and (3) "extreme precipitation event" (i.e., precipitation exceeding the 5-year annual recurrence interval for a location)—and requires coverage of precipitation estimates from hurricanes, atmospheric river flooding events, and extreme precipitation events. (The program compiles, estimates, analyzes, and communicates precipitation frequency data, including heavy precipitation distribution, seasonality, and trends, at least every 10 years.)

This section amends the National Landslide Preparedness Act (NLPA) definitions to add **(1)** "atmospheric river," "atmospheric river flooding event," and "extreme precipitation event" (cross-referencing 15 U.S.C. 9707(a)); **(2)** "institution of higher education" (from the Higher Education Act of 1965); **(3)** "Native Hawaiian organization" (from the Elementary and Secondary Education Act of 1965, expanded to include the Department of Hawaiian Home Lands and Office of Hawaiian Affairs); and **(4)** "Tribal organization" (from the Indian Self-Determination and Education Assistance Act). (The NLPA, led by the U.S. Geological Survey, coordinates federal efforts to reduce losses from landslides through research, risk assessment, mapping, early warning systems, and community preparedness.) It further revises the NLPA national landslide hazards reduction program by **(1)** changing program establishment language from "protect" to "contribute to protecting" life and property; **(2)** changing program activities language from "implement" to "disseminate" best practices; **(3)** requiring the first post-enactment national strategy to assess risks to life and property from atmospheric river flooding events and extreme precipitation events; **(4)** directing the national landslide hazards database to identify areas needing risk assessment due to hydrology changes (including erosion or drought), atmospheric river flooding events and extreme precipitation events, geologic activity (e.g., earthquakes or tsunamis), or data-poor regions; **(5)** expanding landslide hazard and risk preparedness for communities to encompass state and local governments, Indian tribes, Tribal organizations, Native Hawaiian organizations, and other decisionmakers and emergency managers, while adding a focus on reducing losses from atmospheric rivers and other extreme precipitation events; and **(6)** broadening debris flow early warning system development and operation to include Indian tribes, Tribal organizations, and Native Hawaiian organizations.

This section redesignates the existing authority for the Secretary of the Interior to acquire up to 10 acres of land by donation, purchase, or condemnation—and easements or leases—for United States Geological Survey (USGS) stream gaging stations and observation wells as section 1 of the Act of December 24, 1942 (43 U.S.C. 36b), makes conforming amendments (e.g., striking redundant references to "of the Interior" and changing "this Act" to "this section"), and adds section 2 to establish within USGS the Next Generation Water Observing System. The System provides real-time data on water quantity and quality that, compared to previous systems, is more affordable, rapid, and available in more locations to support advanced modeling tools for state-of-the-art flood and drought forecasts, emergency- and water-management decision support, and evaluation of risks from floods, droughts, seasonal snowpacks, evapotranspiration, water quality variations, streamflow-groundwater interactions, and glacial retreat. The System requires state-of-the-art measurements, dense sensor arrays at selected sites, increased spatial and temporal coverage, new technology testing, improved operational efficiency, and modernized data storage and delivery, with priority given to USGS regions facing high drought levels, reliance on reservoirs or hydrologic storage (e.g., groundwater, aquifers, snowpack), or flooding and extreme rainfall. This section authorizes $30 million for FY2026 to implement the System in 10 initial basins as determined by the Secretary, to remain available until expended and derived from amounts appropriated to USGS.

This section revises the Federal priority streamgage program and national groundwater resources monitoring program (42 U.S.C. 10367) as follows: (1) for the streamgage program, requires groundwater quality assessments relating to permafrost thaw and changes in precipitation rates; extends the deadline to increase funded streamgages to at least 4,700 sites, ensure they are flood-hardened with precipitation, water-quality sensors, and modernized telemetry, to 11 years after March 30, 2023 (from 10 years), prioritizes new sites in regions with high drought, reliance on reservoirs or hydrologic storage (including groundwater, aquifers, and snowpack), or flooding and extreme rainfall without affecting existing operating sites that meet stakeholder needs, and increases authorized funding to $30 million annually for FY2026 through FY2033 (from $10 million annually for FY2009 through FY2028), derived from USGS appropriations; and (2) for groundwater monitoring, expands consultation and priority activities to include Indian tribes, Tribal organizations, and Native Hawaiian organizations alongside state and local agencies, adds the same regional priorities as the streamgage program, and specifies that authorized funding be derived from USGS appropriations. (The programs, administered by USGS, collect streamflow and groundwater data to inform water resource management, hydrologic extremes, climate change assessments, and forecasting.)