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EnviroAtlas - National Inventory of Dams by 12-digit HUC for the Conterminous United States

Published by U.S. EPA Office of Research & Development (ORD) - National Exposure Research Laboratory (NERL) | U.S. Environmental Protection Agency | Metadata Last Checked: January 27, 2026 | Last Modified: 2015-05-07T00:00:00.000+00:00
This EnviroAtlas dataset is a summary of the National Dams Inventory data from 2009 survey. The file contains counts of inventoried dams by 12-digit hydrologic units codes (March 2011) and total maximum storage capacity in millions of gallons. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

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