San Gregorio Creek at San Gregorio, CA
River level and flood forecast · San Mateo County
Normal3.7 ftas of Mon 4:15 PM
The river is 14.0 ft below flood stage (17.7 ft).
Flow: 2 cubic feet per second (USGS).
The last 7 days and the forecast
NWS forecast issued Sun, Dec 31, 4 PM. Forecasts change as rain falls and as upstream water arrives.
Get flood alerts for this river
An email when the National Weather Service forecasts San Gregorio Creek at San Gregorio to flood, when it floods, and when it's over.
Flood stages
| Major flood stage | 25 ft |
| Moderate flood stage | 21 ft |
| Flood stage | 17.7 ft |
| Action stage | 15 ft |
What floods at each level
From the National Weather Service, highest first.
- 25 ftMajor flood stage. Stage Road at San Gregorio Creek flooded and adjacent floodplain properties under 4 or more feet of water.
- 21 ftModerate flood stage. Adjacent floodplain under several feet of water. Stage Road crossing is backwatered.
- 17.7 ftMinor flood stage. Flood waters inundate floodplain upstream of Stage Road crossing, mainly on left bank side (as looking downstream). NWS will issue a Flash Flood Warning if not yet already issued.
- 15 ftAction Stage. Water is 2.7 feet below adjacent floodplain properties. NWS may issue a Flash Flood Watch if not yet already issued.
Up and down the river, and nearby
- Pescadero Creek near Pescadero, CA
- Pilarcitos Creek at Half Moon Bay, CA
- San Francisquito Creek at Stanford University, CA
- Pilarcitos Creek below Stone Dam NR Hillsborough, CA
- Pilarcitos Creek above Stone Dam, CA
- San Mateo Creek below Lower Crystal Springs Reservoir NR San Mateo, CA
- Pilarcitos Creek below Pilarcitos Lake Spillway, CA
- San Mateo Creek below Junction Box, CA
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (SXGC1); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.