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EnviroAtlas - Road Density Metrics by 12-digit HUC for the Conterminous United States

Published by U.S. EPA Office of Research and Development (ORD) - Center for Public Health and Environmental Assessment (CPHEA) | U.S. Environmental Protection Agency | Metadata Last Checked: January 27, 2026 | Last Modified: 2022-05-04T00:00:00.000+00:00
This EnviroAtlas dataset describes several metrics related to road-stream crossings and roads near streams at the watershed scale. According to EPA report 600/R-97/130, roads can affect stream water in many ways and roads in close proximity to streams have the most potential for adverse effects on stream water quality. Since roads have an impervious surface, and ditches are built to channel water from roads into streams, the rate of water runoff is higher where there are more roads. Not only does this lead to increased scour of the river channel and stream banks, but it can also be a preferential pathway for runoff associated with road salting or routine maintenance which, along with other spills on the roadway, can lead to overall reductions in water quality. This dataset was produced 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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