National Water Information System: Mapper

Mapper allows users to locate and retrieve data from approximately 1.5 million active and inactive stream gauges sites in all 50 States. You can find current and historical data on stream flow (discharge), temperature, specific conductance, pH, nutrients, pesticides, and volatile organic compounds for steams throughout California. One can also find links to annual stream reports that date major flow changes to a stream and break the flow data accordingly, allowing students to graph and interpret the changes.