National

Aquatic Barrier Inventory & Prioritization Tool

Aquatic Barrier Tool

Pacific Northwest Region

Pacific Northwest region map
Map of 9,826 inventoried dams and 35,737 road-related barriers likely to impact aquatic organisms in the Pacific Northwest region.

Includes 3 states with:

9,826 inventoried dams, including:

  • 31 that have been reconned for social feasibility of removal
  • 133 that have been removed or mitigated, gaining 461 miles of reconnected rivers and streams

712,478 or more potential road-related aquatic barriers, including:

  • 64,229 that have been assessed for impacts to aquatic organisms
  • 35,737 that are likely to impact aquatic organisms
  • 2,861 that have been removed or mitigated, gaining 10,615 miles of reconnected rivers and streams
Explore how many dams or road-related barriers there are in a state, county, or watershed.
Identify and rank dams or road-related barriers that reconnect the most high-quality aquatic networks.

Data Sources

Records describing dams and road-related barriers within Idaho include those maintained by the Idaho Department of Fish and Game.

Records describing dams and road-related barriers within Oregon include those maintained by the Oregon Department of Fish and Wildlife.

Records describing dams and road-related barriers within Washington State include those maintained by the Washington State Department of Fish and Wildlife, Fish Passage Division. For more information about specific structures, please visit the fish passage web map.

Statistics by state:

Inventoried damsReconned damsAssessed road-related barriers
Idaho1,08102,796
Oregon4,3523017,417
Washington4,393144,016
Total9,8263164,229

2,444 inventoried dams and 8,171 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 Pacific Northwest region.

Chum salmon, Allison Springs, WA