NAWQA Data Warehouse Home

What's New? Click here for a list of recent updates

Data subject to change - source data extracted between 12/31/2011 and 1/2/2012.

NAWQA study units image

About the NAWQA Data Warehouse

The U.S. Geological Survey (USGS) began its NAWQA (National Water Quality Assessment) program in 1991, systematically collecting chemical, biological, and physical water quality data from 42 study units (basins) across the nation. The data warehouse currently contains and links the following data:
  • Chemical concentrations in water, bed sediment, and aquatic organism tissues for about 2,500 chemical constituents
  • Site, basin, well and network characteristics with many descriptive variables
  • Daily stream flow information for fixed sampling sites
  • Ground water levels for sampled wells
  • 7,300 surface water sites (including 3,400 reach segments for biological studies) and 9,800 wells
  • 63,000 nutrient samples and 43,000 pesticide samples as well as 12,000 VOC samples
  • 2,700 samples of bed sediment and aquatic organism tissues
  • Biological community data for 15,000 fish, aquatic macroinvertebrate, and algae community samples

Most of these data came from the USGS National Water Information System--NWIS Water-Quality Data for NAWQA sites.