Dams, reservoirs, and high-water events
Photo of high water on Alameda Creek at Alameda Diversion Dam, near Sunol, California.
Monitoring rivers and streams during high-water events
The Consumes River, near Sacramento, experienced record streamflow over the 2022 New Year's holiday weekend as an atmospheric river moved through northern California.
Roads closed due to flooding
A flooded road in San Diego is a common scene throughout Southern California during El Niño-related storms.
The USGS maintains a network of nearly 500 streamgages in California that delivers a continuous source of streamflow data. When water levels change rapidly, or reach flood-stage levels, flood-warning alerts are issued help emergency managers assess potential hazardous conditions near the gage or for downstream locations.