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		Bulletin Group: San Joaquin		River Group: San Joaquin

Action/Monitor: 24.5 Feet

Minor Flood: 29.0 Feet

Moderate Flood: 32.0 Feet

Major Flood: 37.3 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*	10,300	18.12	Mar 6, 2024
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
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

Flood Impacts
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.

Official 7 Day National Weather Service Forecast (CAZ019)

Today: Mostly sunny early in the morning, then a slight chance of rain showers late in the morning. Partly cloudy in the afternoon. Highs 61 to 71. South winds up to 10 mph shifting to the west in the afternoon. Gusts up to 25 mph.

Tonight: Mostly clear. Lows 45 to 51. West winds up to 15 mph with gusts to around 25 mph.

Tuesday: Partly cloudy in the morning then clearing. Highs 66 to 75. Northwest winds up to 15 mph. Gusts up to 25 mph in the afternoon.

Tuesday Night: Clear. Lows 46 to 52. Northwest winds up to 15 mph. Gusts up to 25 mph in the evening.

Wednesday: Sunny, warmer. Highs 74 to 82. Northwest winds up to 10 mph with gusts to around 20 mph.

Wednesday Night: Clear. Lows 49 to 55.

Thursday: Sunny. Highs 80 to 88.

Thursday Night: Mostly clear. Lows 54 to 60.

Friday: Partly cloudy. Highs 79 to 88.

Friday Night and Saturday: Mostly clear. Lows 52 to 58. Highs 77 to 87.

Saturday Night and Sunday: Clear. Lows 51 to 57. Highs 77 to 87.

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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