Streamflow
To help emergency managers and others protect life and property due to floods and other water-related hazards, the USGS delivers a continuous source of streamflow information. The USGS California Water Science Center maintains nearly 500 streamgages that collect data to determine the amount of water flowing in rivers and streams in California. Automatic alerts are transmitted when water levels change rapidly and/or reach flood stage. These alerts help emergency managers assess potential hazardous conditions near the gage or for downstream locations.