Great Lakes Mapping Act of 2025

This bill directs NOAA to create a high‑resolution map of the Great Lakes lakebeds by December 31, 2030. The work includes collecting detailed depth data, organizing existing and new information, and keeping metadata, with portions of the map released to the public as they are finished. After the project ends, the full map and required information must be made public within 180 days, and the data will be added to nautical charts and other products .

NOAA must coordinate with Great Lakes governors, state agencies, national and regional mapping groups, and other relevant partners. The bill authorizes $50 million per year for fiscal years 2025–2029 (available through 2030). It also says this does not change existing processes under the Digital Coast Act or the Ocean and Coastal Mapping Integration Act.

Key points

• Who is affected: NOAA; states that border the Great Lakes; regional ocean observing systems; and people who use public nautical charts and related products.
• What changes: A complete, high‑resolution lakebed map; collection of bathymetric data; cataloging and storing metadata; public release of map data and integration into charts and other products .
• When: Mapping completed by December 31, 2030; parts of the map released during the project; full map released within 180 days after completion; funding for 2025–2029, available through 2030 .