Jump to main content or area navigation.

Contact Us

Water: Wadeable Streams Assessment

Wadeable Streams Assessment

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 2004-2005. The WSA is designed like an opinion poll: that is, 1,392 sites were selected at random to represent the condition of all streams in regions that share similar ecological characteristics. Wadeable streams were chosen for study because they are a critical natural resource and because we have a well-established set of methods for monitoring them. Participants used the same standardized methods at all sites, to ensure results that are comparable across the nation.

The WSA establishes a national baseline we can use to compare to results from future studies. This information will help us evaluate the successes of our national efforts to protect and restore water quality. Along with upcoming studies of other water resource types - coastal waters, lakes, large rivers and wetlands - the WSA responds to criticisms that the nation's monitoring programs are not providing key answers about water quality. The WSA also provides funding and expertise that will enhance each state's ability to monitor and assess the quality of its waters in the future.

Fact Sheets:

Site Evaluation:
Site Evaluation Guidelines (PDF) (15 pp, 225K, About PDF)

Field Methods:
Field Operations Manual (PDF) (191 pp, 14.4MB, About PDF)

Laboratory Methods:
Water Chemistry Laboratory Manual (PDF) (47 pp, 1.1MB, About PDF)
Benthic Laboratory Manual (PDF) (31 pp, 128K, About PDF)

Quality Assurance:
Quality Assurance Project Plan (85 pp, 742K, About PDF)

Data collected for each parameter sampled in the 2004-2005 Wadeable Streams Assessment (WSAA) are available for downloading at the following link:

Wadeable Streams Assessment Data


Jump to main content.