CNRFC - Hydrology - Observed River/Reservoir Conditions

SAN JOAQUIN RIVER - VERNALIS (VNSC1)

Latitude: 37.68º N	Longitude: 121.27º W	Elevation: 35 Feet
Location: San Joaquin County in California		River Group: San Joaquin

Monitor Stage: 24.5 Feet

Flood Stage: 29.0 Feet

Danger Stage: 29.5 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
2023*	34,400	29.82	Mar 19, 2023
2022*	2,600	10.83	Dec 29, 2021
2021*	2,470	10.76	Jan 31, 2021
2020*	6,130	14.29	Dec 9, 2019
2019*	17,200	21.82	Mar 13, 2019
Historical High Stage/Flow Events (Period of Record - Jul 1922 to Present) - Ranked by Flow
1951*	79,000	27.75	Dec 09, 1950
1997*	75,600	34.88	Jan 05, 1997
1969*	52,600	34.55	Jan 27, 1969
1938*	51,200	26.64	Mar 16, 1938
1956*	50,900	26.89	Dec 25, 1955
1983*	45,100	31.49	Mar 07, 1983
* Discharge affected by regulation or diversion

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Official 7 Day National Weather Service Forecast (CAZ019)

Today: Mostly sunny. Widespread fog and locally dense in the morning. Haze through the day. Highs around 63. Light winds.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Haze and patchy fog through the night. Lows 39 to 49. Light winds.

Sunday: Mostly cloudy in the morning then becoming partly cloudy. Haze and widespread fog and locally dense in the morning. Highs 58 to 64. Northwest winds up to 10 mph.

Sunday Night: Mostly clear. Colder. Lows 34 to 44. Light winds.

Monday: Mostly sunny. Highs around 58. Northwest winds up to 10 mph.

Monday Night: Clear. Lows 33 to 43.

Tuesday: Mostly sunny. Highs 56 to 62.

Tuesday Night: Mostly cloudy. Lows 35 to 45.

Wednesday and Wednesday Night: Partly cloudy. Highs around 59. Lows 36 to 46.

Thursday and Thursday Night: Partly cloudy with a slight chance of rain showers. Highs around 59. Lows 38 to 46.

Friday: Mostly cloudy with a chance of rain showers. Highs 54 to 60.

Impacts - E19 Information
37.29 Feet	Stages above 37.3 feet results in flooding outside the levees. Top of levee.
29.6 Feet	Homes along east bank of river on Airport Court in Manteca experience flooding.
26.0 Feet	Severe seepage occurs outside the levees. The area covered by seepage will increase as the river stage rises.
24.5 Feet	Monitor Stage - water reaches the toe of levee.
21.0 Feet	Seepage begins into crop area outside of levees.

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 Sacramento 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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