Santa Margarita River at Ysidora
Future / Actual / Minor
OWP 2.0 WWA Modal Title
01/11/2021, 10:04 PM UTC through 01/11/2021, 10:04 PM UTC
Sender
Sent
- Downstream gauge unavailableWarning: no valid ratings curve available. Transformations to and from FEET/CFS/KCFS will not happen.
Traces and Thresholds Click to turn on/off display
Observed (OBS) 07/03/2025 6:15 AM PDTOfficial Forecast (FCST) 07/02/2025 8:23 AM PDTRecord: 20.5 ftCATEGORY STAGE 
Major Flooding 16 ft Moderate Flooding 13.33 ft Minor Flooding 11.16 ft Action 8.18 ft Reliability of the Forecast: Based on current and forecast river, weather and reservoir conditions
NOTE: Forecasts are issued routinely year-round.
National Water Model Hydrograph
Official NWS streamflow forecasts are produced by NWS hydrologic forecasters for river gauge locations using hydrologic models which are calibrated to that location. This process considers additional guidance and information, including local expertise and experience, to produce the best forecast possible. The NWM output provides supplemental guidance to NWS forecasters and should not be considered an official NWS river forecast.
Flood Impacts
- 16 - Major flood, 37,000 cfs. Widespread inundation of Camp Pendleton with evacuations likely. Flood of Record Jan 16, 1993.
- 13.33 - Moderate flood stage, 17,000 cfs. Vandegrift Road is flooded for several miles downstream of the gage site. Stuart Mesa Road is flooded near the bridge.
- 11.16 - Minor flood stage, 8,000 cfs. Vandegrift Road has begun to flood downstream of the gage. Stuart Mesa Road closures can be expected.
Gauge Info
| Coordinates | 33.3111, -117.347 |
| RFC | CNRFC |
| State | CA |
| WFO | SGX |
| County | San Diego |
| Data Provider(s) | |
| US Geological Survey | USGS--Water Resources of the United States |
| USGS | 11046000 |
Gauge Location
Recent Crests
| 1. | 11.73 ft | on 01-16-2023 |
| 2. | 15.07 ft | on 02-14-2019 |
| 3. | 14.60 ft | on 01-22-2017 |
| 4. | 12.41 ft | on 02-23-1998 |
| 5. | 12.68 ft | on 01-10-1995 |
Recent Crests
| 1. | 11.73 ft | on 01-16-2023 | |
| 2. | 15.07 ft | on 02-14-2019 | |
| 3. | 14.60 ft | on 01-22-2017 | |
| 4. | 12.41 ft | on 02-23-1998 | |
| 5. | 12.68 ft | on 01-10-1995 | |
| 6. | 20.47 ft | on 01-16-1993 | 1 |
| 7. | 11.20 ft | on 03-01-1991 | |
| 8. | 10.40 ft | on 03-02-1983 | |
| 9. | 18.80 ft | on 02-18-1980 | 1 |
| 10. | 18.12 ft | on 03-01-1978 | 1 |
| 11. | 15.89 ft | on 02-25-1969 | 1 |
| 12. | 14.05 ft | on 01-23-1943 | |
| 13. | 12.70 ft | on 03-03-1938 | |
| 14. | 10.50 ft | on 02-07-1937 | |
| 15. | 18.00 ft | on 02-16-1927 | 1 |
Historic Crests
| 1. | 20.47 ft | on 01-16-1993 | 1 |
| 2. | 18.80 ft | on 02-18-1980 | 1 |
| 3. | 18.12 ft | on 03-01-1978 | 1 |
| 4. | 18.00 ft | on 02-16-1927 | 1 |
| 5. | 15.89 ft | on 02-25-1969 | 1 |
Historic Crests
| 1. | 20.47 ft | on 01-16-1993 | 1 |
| 2. | 18.80 ft | on 02-18-1980 | 1 |
| 3. | 18.12 ft | on 03-01-1978 | 1 |
| 4. | 18.00 ft | on 02-16-1927 | 1 |
| 5. | 15.89 ft | on 02-25-1969 | 1 |
| 6. | 15.07 ft | on 02-14-2019 | |
| 7. | 14.60 ft | on 01-22-2017 | |
| 8. | 14.05 ft | on 01-23-1943 | |
| 9. | 12.70 ft | on 03-03-1938 | |
| 10. | 12.68 ft | on 01-10-1995 | |
| 11. | 12.41 ft | on 02-23-1998 | |
| 12. | 11.73 ft | on 01-16-2023 | |
| 13. | 11.20 ft | on 03-01-1991 | |
| 14. | 10.50 ft | on 02-07-1937 | |
| 15. | 10.40 ft | on 03-02-1983 |
Unique Local Info
Degree of impact may be influenced by the tide level near the coast.
Collaborative Agencies
The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here.