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Quantifying National Fish Passage Data

Birdseye view of Dalles North Fishway
Dalles North Fishway. Credit: Northern Wasco County Public Utility District



Hydropower provides nearly 7% of all electricity generated in the United States and is expected to be increasingly relied upon for flexibility as we shift to greater contributions of renewable intermittent power from solar and wind. Its potential contributions to the US power grid and implications for the environment require a more thorough understanding of the effects of hydropower dams on aquatic species living near these facilities. Because dams can act as barriers to complex lifecycle requirements, such as fish migration, a variety of mitigating technologies to facilitate fish passage up- and downstream of dams have been developed and deployed over the years. However, national information on fish passage facilities is incomplete and often limited to data from the planning stages. The absence of a comprehensive and centralized dataset on these facilities leaves a critical knowledge gap in implementation and operational costs, as well as in ensuring safe, timely, and effective fish passage.

Researchers at Oak Ridge National Laboratory (ORNL) have initiated a one-of-a-kind project to create the first central repository for geo-referenced and -attributed data on fish passage facilities at hydropower installations across the United States. ORNL is partnering with fish passage engineers at the US Fish and Wildlife Service and the National Oceanic and Atmospheric Administration, as well as hydropower experts at the Low Impact Hydropower Institute.

Water tank with fish
Lowell Project fish lift. Credit: Shannon Ames


ORNL researchers are approaching the project with three primary goals:

  • Obtain greater detail on fish passage technologies and operations currently deployed at hydropower developments across the United States
  • Uncover information on the costs to construct, operate, and maintain such technologies
  • Identify and document reference information for passage performance studies conducted at each facility

ORNL is working to secure publicly available data from project partners and from hydropower licensing documents filed with the Federal Energy Regulatory Commission. In addition, ORNL is engaging with industry by administering an online questionnaire to hydropower owners and operators to gather insights into technical and engineering features, total costs, and performance studies.

During the first year of the project, ORNL researchers developed a web-based map of fish passage infrastructure and river networks in the New England hydrologic region. The map, which debuted in a January 2024 webinar, connects the locations of hydropower developments with stream and river data from the USGS National Hydrography Dataset, enabling database users to evaluate collective fish passage capabilities within watersheds in New England. From these data, ORNL researchers expect to develop methodologies for compiling fish passage data and performance studies at a national scale.

Snowy bridge next to waterway
Buffalo River Fishway. Credit: Fall River Rural Electric Cooperative


As one of the nation’s largest sources of renewable energy, hydropower plays a large and growing role in the country’s pursuit of clean, resilient, and environmentally friendly energy production.

Documenting current deployment of fish passage technologies across the United States can provide key insights into how best to preserve and maintain safe ecological habitats for the species that reside in these rivers and reservoirs. A national dataset that includes comprehensive cost outlays is also expected to assist hydropower operators in more effectively planning projects, anticipating costs required for passage facility construction, operation, and maintenance, and better understanding the potential connectivity provided by fish passage at larger spatial scales.