Skip to main content
U.S. flag

An official website of the United States government

This site is currently in beta, and your feedback is helping shape its ongoing development.

Return to search results

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 | Metadata Last Checked: July 31, 2025 | Last Modified: 2009-12-23
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.

data.gov

An official website of the GSA's Technology Transformation Services

Looking for U.S. government information and services?
Visit USA.gov