The Great Lakes Mapping Act of 2025 directs the Administrator of the National Oceanic and Atmospheric Administration (NOAA) to carry out a high-resolution survey and mapping program of the lakebeds across the Great Lakes. The effort is designed as a collaborative mapping program with specific elements: produce a high-resolution map, collect and process bathymetric data, catalog and reuse existing data, and capture metadata produced during the effort.
A key feature is public-data accessibility: parts of the completed map should be publicly available during the mapping effort and, within 180 days after completion, the full map and required metadata must be released, with data incorporated into nautical charts and related products where appropriate. The bill also directs interagency coordination with states, regional observing systems, and other relevant entities and authorizes funding to support the effort while preserving existing data-management frameworks.
At a Glance
What It Does
NOAA must conduct a high-resolution mapping of the Great Lakes lakebeds, coordinate with state and regional partners, and publicly release the data and metadata while integrating findings into nautical charts.
Who It Affects
NOAA, state governors and natural-resources agencies bordering the Great Lakes, regional ocean observing systems, and maritime charting entities that rely on bathymetric data.
Why It Matters
Public, standardized bathymetric data enhances navigation safety, supports habitat and resource planning, and strengthens cross-jurisdictional coordination for Great Lakes management.
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What This Bill Actually Does
NOAA is tasked with a comprehensive, high-resolution mapping project of the Great Lakes lakebeds. The act specifies the core tasks—map creation, bathymetric data collection, cataloging of existing datasets, and rigorous metadata capture—and sets a public data-release requirement designed to ensure accessibility and reuse.
Coordinated efforts with border-state governors, state agencies, and regional observing networks are intended to align mapping with ongoing regional efforts and data standards. The resulting products will feed into nautical charts and other mapping outputs used for navigation, habitat assessment, and resource planning.
The act also establishes a dedicated funding stream for this program, with the understanding that data products should be available publicly within a defined timeframe, while remaining consistent with existing federal mapping and coastal data programs.
The Five Things You Need to Know
The bill directs NOAA to complete high-resolution mapping of the Great Lakes lakebeds by December 31, 2030.
Data management requires publicly releasing the completed map and metadata within 180 days after mapping concludes.
NOAA must coordinate the effort with state governments, regional observing systems, and related bodies.
Public data release is paired with incorporating the lakebed data into nautical charts and related products.
The act authorizes $50 million per fiscal year (2025–2029) for the mapping effort, with funding available through 2030.
Section-by-Section Breakdown
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Short title
Be it enacted as the Great Lakes Mapping Act of 2025. This section designates the Act by its formal name and provides the citation reference for congressional use.
High-Resolution Lakebed Mapping—Scope
This subsection requires NOAA to conduct a collaborative, high-resolution survey and map of the Great Lakes lakebeds. The mapping must be completed no later than December 31, 2030, and should be designed as a coordinated effort involving NOAA and relevant regional partners to ensure comprehensive coverage and data interoperability.
Elements of the Mapping Effort
The mapping effort must include (1) producing a high-resolution lakebed map; (2) collecting and processing bathymetric data; (3) cataloging existing bathymetric data and related information possessed or accessible to NOAA; and (4) collecting, cataloging, and storing metadata generated during the effort. These components ensure both a usable product and an auditable data trail for downstream users.
Coordination
NOAA must coordinate with the governors of Great Lakes states, state agencies responsible for Great Lakes policy, the National Ocean Mapping, Exploration, and Characterization Council, the Lakebed 2030 Regional Initiative of the Great Lakes Observing System, other regional observing systems, and any other entities the Administrator deems relevant. Coordination aims to harmonize standards, avoid duplicative efforts, and maximize reuse of existing data and capabilities.
Data Management; Product Sharing
During the mapping effort, NOAA should publicly release the completed portions of the high-resolution map in a timely manner. Within 180 days after completing the mapping effort, NOAA must publicly release the complete map and associated metadata, to the extent required by law, and incorporate the data into additional products such as nautical charts and other suitable resource-mapping outputs.
Rule of Construction
This section does not alter any process or procedure used by NOAA under the Digital Coast Act or the Ocean and Coastal Mapping Integration Act. The intent is to preserve existing statutory frameworks while advancing the Great Lakes mapping objective.
Authorization of Appropriations
There is authorized to be appropriated $50,000,000 to NOAA for each fiscal year 2025 through 2029 to carry out Section 2. These funds remain available through fiscal year 2030 to support the mapping effort, data management, and related products.
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Who Benefits
- State natural resources departments in Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin benefit from standardized data to guide management and policy.
- Coastal and maritime planners, port authorities, and commercial shipping interests benefit from updated, publicly available nautical charts and bathymetric data for safer navigation.
- Great Lakes Observing System and the Lakebed 2030 Regional Initiative gain clearer data inputs and data-sharing foundations to advance regional science and mapping efforts.
- Environmental researchers and universities gain access to standardized bathymetric datasets and metadata for habitat characterization and scientific studies.
Who Bears the Cost
- NOAA’s federal budget and annual appropriations must cover the mapping effort and data management.
- State governments incur coordination and data-sharing costs (staff time, interagency collaboration, and potential data-system interface work).
- Regional ocean observing systems may need to align data standards and participate in data-sharing workflows, with associated administrative costs.
- Maritime charting agencies and users may incur costs to adopt new data or update products as the data is released and integrated.
Key Issues
The Core Tension
The central tension is balancing an ambitious, publicly accessible, high-resolution mapping program with finite funding, intergovernmental coordination challenges, and the need to maintain data quality and consistency across diverse stakeholders.
The bill creates a high-visibility, data-intensive program that will require substantial interagency coordination and ongoing funding. Real-world implementation will hinge on managing large data volumes, ensuring data quality and interoperability across multiple jurisdictions, and aligning federal timelines with state and regional data initiatives.
There is a need to reconcile the ambition of rapid, public data release with the practical realities of data validation, standardization, and long-term maintenance. Additionally, while the act references existing data frameworks, close attention will be required to ensure consistency with Digital Coast Act and Ocean and Coastal Mapping Integration Act requirements and to avoid duplicative efforts across agencies.
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