ABOUT LHDI

History

While low-head dams have long been a part of the nation’s waterways, no single dataset existed that showed where they were located.

The Task Force, led by Professor Rollin Hotchkiss from Brigham Young University, focused on collecting and crowdsourcing information about low-head dams. Data was collected using a mobile application, existing state inventories, Google Earth, and machine learning. Task Force efforts began in 2021 and by 2024, more than 13,000 structures were identified; the type and quality of data available for these structures greatly varied.

The U.S. Army Corps of Engineers maintains the National Inventory of Dams and publishes available data on many types of dams, now including a low-head dam dataset. Publishing information about low-head dams in the U.S. is an important step to helping people understand the dangers of low-head dams and support actions to improve safety.

In 2022, Congress authorized the U.S. Army Corps of Engineers to develop a national inventory of low-head dams to improve public safety. The U.S. Army Corps of Engineers maintains the National Inventory of Dams and planned to publish low-head dam information within that platform.

Work to publish the low-head dam data in the National Inventory of Dams began in 2024. This included building a data viewer, developing educational webpages, and reviewing and publishing an initial dataset.

The U.S. Army Corps of Engineers used Task Force-collected information to populate the initial dataset, first completing minimal review to confirm the location of dams captured and that they appear to meet the definition of a low-head dam as described in the Water Resources and Development Act of 2024.

About 4,000 datapoints have been marked for possible removal from the low-head dam dataset. No additional data was collected, and the quality of available information was not verified by the U.S. Army Corps of Engineers.

The Low-Head Dam Inventory was published in 2025. Today, site visitors can see information for about 10,000 low-head dams nationwide. The Low-Head Dam Inventory was published in 2025. Today, site visitors can see information for about 10,000 low-head dams nationwide.

Publishing this data is an important step forward for public safety, but more work is needed to continue to improve available information. This includes adding locations of additional dams and determining how additional data could be collected, such as the current use or ownership of the dam.

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