National

Aquatic Barrier Inventory & Prioritization Tool

Aquatic Barrier Tool

Photo: Adam Bouse

Great Lakes Region

(in development)
Great Lakes region map
Map of 24,539 inventoried dams and 12,372 road-related barriers likely to impact aquatic organisms in the Great Lakesregion.

Includes 7 states with:

24,539 inventoried dams, including:

  • 619 that have been reconned for social feasibility of removal
  • 1,074 that have been removed or mitigated, gaining 80,404 miles of reconnected rivers and streams

889,219 or more potential road-related aquatic barriers, including:

  • 28,777 that have been assessed for impacts to aquatic organisms
  • 12,372 that are likely to impact aquatic organisms
  • 350 that have been removed or mitigated, gaining 930 miles of reconnected rivers and streams

Progress toward restoring aquatic connectivity:

year removed
show:miles gained|number removed
2023
143 miles*
2022
2,072 miles*
2021
1,859 miles*
2020
1,787 miles*
2010-2019
9,993 miles*
2000-2009
8,296 miles*
before 2000
4,270 miles*
unknown
52,913 miles*
dams
road-related barriers
* includes 115 dams and / or road-related barriers that could not be correctly located on the aquatic network or were otherwise excluded from the analysis; these contribute toward the count but not the miles gained.
Explore how many dams or road-related barriers there are in a state, county, or watershed.
Explore dams and road-related barriers that have been removed or mitigated by state, county, or watershed.
Identify and rank dams or road-related barriers that reconnect the most high-quality aquatic networks.

Statistics by state:

Inventoried damsReconned damsAssessed road-related barriers
Illinois1,666165
Indiana1,602772
Iowa4,4322710
Michigan2,64324714,858
Minnesota2,308586,562
Ohio7,09647850
Wisconsin4,7922326,360
Total24,53961928,777

6,068 inventoried dams and 3,240 assessed road-related barriers were not analyzed because they could not be correctly located on the aquatic network or were otherwise excluded from the analysis. You can optionally include these in your download.

Note: These statistics are based on inventoried dams and road-related barriers. Because the inventory is incomplete in many areas, areas with a high number of dams may simply represent areas that have a more complete inventory.


You can help!

You can help improve the inventory You can help improve the inventory by sharing data, assisting with field reconnaissance to evaluate the impact of aquatic barriers, or even by reporting issues with the inventory data in this tool.

Contact us to learn more about how you can help improve aquatic connectivity in the Great Lakes region.