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Wadeable Streams Assessment Data

Published by U.S. EPA Office of Water (OW) - Office of Wetlands Oceans and Watersheds (OWOW) | U.S. Environmental Protection Agency | Catalog Last Checked: May 01, 2026 at 06:08 PM | Dataset Last Updated: December 23, 2009
The Wadeable Streams Assessment (WSA) is a first-ever statistically-valid survey of the biological condition of small streams throughout the U.S. EPA worked with the states to conduct the assessment in 2000-2004. 1,392 sites were selected at random to represent the condition of all streams in regions that share similar ecological characteristics. Participants used the same standardized methods at all sites, to ensure results that are comparable across the nation.

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