CNRFC - Hydrology - Observed River/Reservoir Conditions

*** IMPORTANT *** Week of June 16 - Website Data Outage - Due to a major computer upgrade the week of June 16, nearly all data on the CNRFC web site will not be updated. We anticipate the down time to be approximately 4 days. The latest deterministic hydrologic forecasts for official forecast points will continue to be available at the National Water Prediction Service during this time.

SANTA MARGARITA RIVER - YSIDORA (YDRC1)

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

Monitor Stage: 8.2 Feet

Flood Stage: 11.2 Feet

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

Official 7 Day National Weather Service Forecast (CAZ043)

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

Monday: Patchy fog in the morning. Partly cloudy. Highs 72 to 76 near the coast to 80 inland. Areas of winds west to 10 mph.

Monday Night: Partly cloudy. Patchy fog overnight. Lows around 60. Areas of winds west 10 mph in the evening becoming light.

Tuesday: Patchy fog in the morning. Partly cloudy. Highs 73 to 76 near the coast to 79 to 82 inland. Areas of winds south to 10 mph.

Tuesday Night: Partly cloudy. Patchy fog overnight. Lows around 60. Areas of winds southwest 10 mph in the evening becoming light.

Wednesday: Patchy fog in the morning. Partly cloudy. Highs 71 to 75 near the coast to 78 inland.

Wednesday Night: Partly cloudy in the evening and becoming mostly cloudy. Lows 57 to 61.

juneteenth: Mostly cloudy in the morning and becoming partly cloudy. Highs 71 to 74 near the coast to 78 inland.

Thursday Night: Partly cloudy in the evening and becoming mostly cloudy. Lows around 60.

Friday: Partly cloudy. Highs 71 to 75 near the coast to 78 inland.

Friday Night: Partly cloudy in the evening and becoming mostly cloudy. Lows 57 to 61.

Saturday: Cloudy in the morning and becoming partly cloudy. Highs 69 to 72 near the coast to 75 inland.

Saturday Night: Partly cloudy in the evening and becoming cloudy. Lows around 60.

Sunday: Mostly cloudy in the morning and becoming partly cloudy. Highs 69 to 74 near the coast to 74 inland.

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.

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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