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Advanced Hydrologic Prediction Service
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This probabilistic forecast is issued by the California Nevada River Forecast Center.
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About this graph
Forecasts for the Santa Margarita River at Ysidora are issued routinely year-round.
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Zoom Level:14
Flood Categories (in feet)
Major Flood Stage: 16
Moderate Flood Stage: 13.33
Flood Stage: 11.2
Action Stage: 8.18
Low Stage (in feet): -9999

Historic Crests
(1) 20.47 ft on 01/16/1993
(2) 18.80 ft on 02/18/1980
(3) 18.12 ft on 03/01/1978
(4) 18.00 ft on 02/16/1927
(5) 15.89 ft on 02/25/1969
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(P): Preliminary values subject to further review.

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
Show More Recent Crests

(P): Preliminary values subject to further review.

Low Water Records
(1) 3.20 ft on 10/01/1999
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Gauge LocationGauge Map Marker
Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.
Flood Impacts & Photos Collapse
If you notice any errors in the below information, please contact our Webmaster
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.
8.18 2,500 cfs. The river has reached monitor stage. Personnel begin regular patrols along the levee.

Other Real-time and/or Archive Data Sources:

Additional Information Collapse
Degree of impact may be influenced by the tide level near the coast.
Collaborative Agencies Collapse
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.
NWS Information
National Weather Service
San Diego Weather Forecast Office
11440 W. Bernardo Court, Suite 230
San Diego, CA 92127
(858) 675-8700
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Page last modified: 2-Nov-2020 7:27 PM
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