CNRFC - Hydrology - Observed River/Reservoir Conditions

SANTA MARGARITA RIVER - YSIDORA (YDRC1)

Latitude: 33.31º N	Longitude: 117.35º W	Elevation: 75 Feet
Location: San Diego County in California		Bulletin Group: Southern California		River Group: San Diego/Inland

Action/Monitor: 8.2 Feet

Minor Flood: 11.2 Feet

Moderate Flood: 13.3 Feet

Major Flood: 16.0 Feet

Plot Type:

Observed Data Credit
	Raw streamflow data is provided by the US Geological Survey (USGS). View US Geological Survey (USGS) Data for this station location.

Historical Stage/Flow Data
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2024*	8,250	11.26	Mar 31, 2024
2023*	11,100	11.73	Jan 16, 2023
2022*	4,270	9.37	Dec 24, 2021
2021*	1,120	7.31	Dec 29, 2020
2020*	6,680	10.78	Apr 10, 2020
Historical High Stage/Flow Events (Period of Record - Sep 2001 to Present)** - Ranked by Flow
1993*	44,000***	20.47***	Jan 16, 1993
1927	33,600****	18.00	Feb 16, 1927
2017*	31,200	14.60	Jan 22, 2017
1938	31,000	12.70	Mar 3, 1938
2019*	29,500	15.07	Feb 14, 2019
2005*	25,600***	13.5***	Jan 11, 2005
1980*	24,000***	18.80	Feb 18, 1980

* Discharge affected by regulation or diversion
** Most recent continuous record back to Sep 2001 with segmented periods back to Feb 1923
*** Estimated value
**** Highest flow since regulation by Skinner Reservoir began in 1974

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Flood Impacts
16.0 Feet	Major flood, 37,000 cfs. Widespread inundation of Camp Pendleton with evacuations likely. Flood of Record Jan 16, 1993.
13.33 Feet	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 Feet	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 Feet	2,500 cfs. The river has reached monitor stage. Personnel begin regular patrols along the levee.

Official 7 Day National Weather Service Forecast (CAZ043)

Tonight: Mostly clear This Evening and becoming partly cloudy. Patchy fog overnight. Lows 60 to 66. Areas of winds northwest 10 mph This Evening becoming light.

Wednesday: Partly cloudy with patchy fog in the morning and Becoming mostly sunny. Highs 75 to 78 near the coast to 82 to 85 inland. Areas of winds west to 10 mph.

Wednesday Night: Mostly clear in the evening and becoming partly cloudy overnight with patchy fog. Lows 60 to 66. Areas of winds west 10 mph in the evening becoming light.

Thursday: Partly cloudy with patchy fog in the morning and Becoming mostly sunny. Highs 74 to 78 near the coast to 82 to 85 inland. Light winds becoming west 10 mph in the afternoon.

Thursday Night: Mostly clear in the evening and becoming partly cloudy overnight with patchy fog. Lows 59 to 64. Light winds.

Friday: Cloudy in the morning and becoming partly cloudy. Patchy fog in the morning. Highs 72 to 75 near the coast to 80 inland.

Friday Night: Mostly clear in the evening and becoming cloudy overnight with patchy fog. Lows 57 to 63.

Saturday: Cloudy with patchy fog in the morning and becoming mostly sunny. Highs 70 to 74 near the coast to 78 inland.

Saturday Night: Mostly clear in the evening and becoming cloudy overnight with patchy fog. Lows 58 to 63.

Sunday: Cloudy in the morning and becoming mostly sunny. Highs 71 to 75 near the coast to 80 inland.

Sunday Night: Mostly clear in the evening and becoming mostly cloudy. Lows 57 to 64.

Monday: Cloudy in the morning and becoming partly cloudy. Highs 71 to 75 near the coast to 76 to 79 inland.

Monday Night: Mostly clear in the evening and becoming mostly cloudy. Lows 58 to 63.

Tuesday: Cloudy in the morning and becoming mostly sunny. Highs 70 to 74 near the coast to 77 inland.

Product Disclaimer

This river graphic is not intended to serve as a substitute for official flood watches, warnings, advisories, or statements issued by the NWS San Diego Weather Forecast Office. Observations are preliminary and subject to change. River levels identified as "forecast" should be consistent with those contained in official NWS products. River levels identified as "guidance" have significant uncertainty due to future weather or reservoir regulation and are provided for planning purposes only.

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