USGS Water-Quality Information
Water Quality Data
Today's Water Conditions
Get continuous real-time water-quality measurements from Water-Quality Watch maps.
Water Quality Portal (WQP)
Get current and historical USGS and EPA water-quality data at the WQP.
Get stream ecosystem aquatic bioassessment data from BioData.
For More Data
USGS in Your Area
USGS Water Science Centers are located in each state.
National Field Manual for the Collection of Water-Quality Data
Techniques of Water-Resources Investigations