What changed between these versions
A complete substitute amendment, v5 significantly redefines the Snow Water Supply Forecasting Program. It updates the program's short title, expands the focus to include water supply forecasting and new modeling technologies like machine learning, and fundamentally restructures the reporting requirements for program outcomes and technology assessments. The changes aim for more accurate and timely forecasts to inform multi-scale water management decisions.
Overview
Extensive changes are present throughout the bill, affecting nearly every section of the Snow Water Supply Forecasting Program Authorization Act that was proposed for amendment in v4. · v5 represents a restructuring and expansion of the program's focus, shifting from primarily snowpack measurement and integrated modeling to a broader emphasis on water supply forecasting, including the exploration of new statistical and machine learning models.
The most significant change in v5 is the expansion of the program's mandate to explicitly include water supply forecasting and the integration of advanced analytical methods like machine learning, moving beyond just snowpack measurement. This is reflected in modified language across multiple subsections, particularly in the program's focus and the types of technologies to be utilized. Additionally, v5 completely overhauls the reporting requirements, introducing new assessments for technology effectiveness and forecast accuracy against benchmarks. The short title and reauthorization years have also been updated.
Major additions
v5 explicitly adds 'machine learning' as a technology for snowpack measurements and methods to forecast water supply. This was not explicitly listed in v4's proposed list of technologies.
The explicit inclusion of machine learning broadens the technological scope of the program, allowing for the adoption of more advanced predictive analytics to improve water supply forecasts. This could lead to more sophisticated and accurate models for water management.
v5 adds a new directive for the program to 'explore new statistical, machine learning, or physical models to generate improved water supply forecasts utilizing snowpack data' within particular watersheds.
This addition significantly expands the program's research and development mandate beyond just measurement and integrated modeling, pushing for innovation in forecasting methodologies. It directly supports the broader emphasis on water supply forecasting and the use of advanced analytics.
v5 introduces two new reporting requirements: (1) an assessment of which technologies best inform water supply forecasting for multiple water districts, communities, or States; and (2) an assessment of forecasts generated using new technologies compared against benchmarks from the Department of Agriculture and the National Oceanic and Atmospheric Administration.
These additions create more rigorous accountability and evaluation mechanisms for the program. They require a comparative analysis of technology effectiveness and forecast accuracy, which can guide future investments and improve the utility of the program's outputs for diverse stakeholders.
Deletions
v4 proposed to replace the original Act's list of technologies with a new list, starting with 'airborne laser altimetry'. v5's approach to the technology list implicitly removes this specific insertion by retaining the original Act's subparagraph (A) 'airborne lidar' and adding new items differently.
The deletion of v4's specific replacement for original subparagraph (A) means that the program will continue to consider 'airborne lidar' as a technology, rather than exclusively 'airborne laser altimetry' as v4 had specified. This maintains a broader scope for airborne measurement technologies.
v4's proposed focus for the program included 'real-time integration of activities described in this section with water supply forecasts'. This specific point is omitted in v5's revised focus statement.
The removal of this explicit focus on 'real-time integration' might suggest a slight de-emphasis on immediate, continuous data integration, or it could be subsumed within the broader goal of improved forecasting. It removes a specific operational directive from the program's focus.
Modifications
This is a minor, administrative change, updating the official name and year of the reauthorization act.
Before
The short title was 'Snow Water Supply Forecasting Reauthorization Act of 2025'.
After
The short title is 'Snow Water Supply Forecasting Program Reauthorization Act of 2026'.
This modification clarifies that the program is an ongoing effort ('continue developing') and explicitly broadens its technological scope to include cost-effectiveness and a direct link to water supply forecasting, affecting how technologies are prioritized and implemented.
Before
v4 amended the text to emphasize 'deployment of technologies that provide integration of snowpack measuring and modeling'.
After
v5 further amends the text to 'continue developing' (instead of 'develop') and emphasizes 'development and deployment of more accurate, timely, and cost-effective snow monitoring technologies and water supply forecasting, including technologies that integrate snowpack measuring and modeling'.
This modification explicitly states that improving water supply forecasting is a direct goal of the program's activities in particular watersheds, providing a clearer mandate for its outcomes.
Before
v4 struck text related to a report requirement.
After
v5 also strikes the same report-related text and additionally inserts 'and to improve water supply forecasting' after 'watersheds'.
This shifts the emphasis in the heading from 'integrated modeling' to the broader outcome of 'water supply forecasting', aligning with the overall directional change of the bill.
Before
v4 added 'with integrated modeling' to the heading of paragraph (1).
After
v5 inserts 'and water supply forecasting' to the heading of paragraph (1).
This modification broadens the scope from 'complete integration' of measurements and models to include 'methods to forecast water supply', indicating a shift towards analytical techniques alongside measurement technologies.
Before
v4 replaced 'emerging technologies for snowpack measurement, such as' with 'technologies that provide complete integration of accurate, timely, and spatially complete snowpack measurements and models, including the integration of'.
After
v5 replaces 'emerging technologies for snowpack measurement, such as' with 'technologies for snowpack measurements and methods to forecast water supply, including'.
This change means the program will continue to utilize original technologies like 'airborne lidar' and 'cosmic-ray snow sensors' (with a minor grammatical change), while also adding 'machine learning' and refining the description of 'snowpack and hydrologic modeling'. This provides a more comprehensive and expanded set of tools rather than a complete replacement, affecting the range of methods employed.
Before
v4 struck the original Act's subparagraphs (A) through (C) and inserted a new list: (A) airborne laser altimetry; (B) imaging spectroscopy; (C) integrated physics-based snowpack and hydrologic modeling; and (D) other technologies.
After
v5 modifies the original Act's subparagraph (B) by striking 'and' at the end, and strikes the original Act's subparagraph (C) to insert a new list: (C) imaging spectroscopy; (D) machine learning; (E) snowpack and hydrologic modeling; and (F) other technologies. (Original (A) is implicitly retained).
This modification changes the context of agency collaboration, explicitly mentioning the Department of Agriculture (USDA) and NOAA in relation to 'technologies for snowpack measurement and models', while removing the specific mention of the Natural Resources Conservation Service (NRCS) from this particular clause. This could affect interagency coordination and resource allocation.
Before
v4 inserted ', including the National Oceanic and Atmospheric Administration and the Natural Resources Conservation Service,' after 'other Federal agencies'.
After
v5 strikes 'emerging technologies for snowpack measurement' and inserts 'technologies for snowpack measurement and models, including the Department of Agriculture and the National Oceanic and Atmospheric Administration'.
This consistently removes a prior reporting requirement, streamlining administrative burdens related to specific reports.
Before
v4 struck paragraph (3).
After
v5 also strikes paragraph (3).
This consistently removes a dependency on a prior report for the program's activities to commence, allowing it to operate continuously.
Before
v4 struck text related to a report requirement.
After
v5 also strikes the same report-related text.
This modification shifts the program's core focus from 'integrated modeling' to 'modeling projected water supply', explicitly removes the 'real-time integration' sub-point from v4, and expands the scope of activities in river basins to include multi-water user, multi-basin, or multi-State scales. This broadens the applicability and impact of the program's outputs on water management decisions.
Before
v4 struck paragraph (2) and inserted a new focus statement emphasizing 'snowpack measurement and integrated modeling' with four sub-points (A)-(D).
After
v5 struck paragraph (2) and inserted a new focus statement emphasizing 'snowpack measurement and modeling projected water supply' with three sub-points (A)-(C).
This is a minor, administrative change to ensure consistency with the updated short title of the reauthorization act.
Before
v4 modified the reference to the Act's short title to 'of the Snow Water Supply Forecasting Reauthorization Act of 2025'.
After
v5 modified the reference to the Act's short title to 'the Snow Water Supply Forecasting Program Reauthorization Act of 2026'.
This significantly enhances the granularity and scope of reporting. Instead of just listing technologies and their use, the program must now provide assessments of technology effectiveness for multi-stakeholder water supply forecasting and compare new forecasts against established benchmarks. This will provide more actionable insights for policymakers and water managers.
Before
v4 modified paragraph (1) to strike 'and sub-basins', insert 'and integrated modeling technologies' after 'technologies', and replace 'technology used' with 'application, outcome, and data resources used'.
After
v5 strikes paragraph (1) entirely and inserts three new paragraphs: (1) a list of basins with descriptions of application, outcome, and data resources; (2) an assessment of technologies for water supply forecasting; and (3) an assessment of new forecasts against benchmarks.
This consistently removes the reference to 'sub-basins' in the reporting requirements, simplifying the scope of geographic reporting to focus on larger 'basins'.
Before
v4 struck 'or sub-basin' from paragraph (2).
After
v5 also strikes 'or sub-basin' from the renumbered paragraph (4).
This consistently updates the program's reauthorization period and funding levels, ensuring continued financial support for its operations from fiscal years 2027 through 2031 at a specified annual amount.
Before
v4 struck '$15,000,000, in the aggregate, for fiscal years 2022 through 2026' and inserted '$3,000,000 for each of fiscal years 2027 through 2031'.
After
v5 also strikes '$15,000,000, in the aggregate, for fiscal years 2022 through 2026' and inserts '$3,000,000 for each of fiscal years 2027 through 2031'.
Scope
Fundamental restructuring — Changes are scattered throughout the entire amending section, affecting the short title, program objectives, authorized technologies, agency collaboration, and reporting requirements. — v5 represents a meaningful change in policy direction by significantly expanding the program's focus from primarily snowpack measurement and integrated modeling to explicitly include water supply forecasting and the exploration of advanced analytical models like machine learning. — The changes interact significantly with existing provisions by redefining the program's core purpose, expanding the types of technologies and methods it can employ, and establishing more detailed and outcome-oriented reporting requirements. The new reporting requirements, in particular, will influence how the program's activities are planned and evaluated.
Impact analysis
Federal agencies involved in snow and water supply forecasting (e.g., NOAA, USDA)
Procedural change and increased accountability.
v5 explicitly includes the Department of Agriculture (USDA) in the list of collaborating Federal agencies for snowpack measurement and models, while removing the specific mention of the Natural Resources Conservation Service (NRCS) from that particular clause (though NRCS is part of USDA). It also adds new reporting requirements for comparing forecasts against benchmarks from USDA and NOAA.
Water managers and users (including those involved in interstate water management)
Gain of improved data and decision-making tools.
The program's expanded focus on 'water supply forecasting' and the exploration of 'new statistical, machine learning, or physical models' aims to provide more accurate and timely forecasts. The program's activities in river basins are now explicitly directed to inform water management decisions at 'multi-water user, multi-basin, or multi-State scale'.
Researchers and developers of snow monitoring and water forecasting technologies
Gain of expanded opportunities and clearer research directives.
v5 explicitly adds 'machine learning' as an authorized technology and directs the program to 'explore new statistical, machine learning, or physical models'. This provides a clear mandate and potential funding for research and development in these advanced areas.
Program partners (e.g., State, local, and tribal entities)
Procedural change with potential for enhanced capabilities.
The program's focus on 'building the capacity of program partners to implement and adapt to the new measurement and forecasting capabilities' remains, but the capabilities themselves are expanded to include more advanced forecasting methods.