CNRFC - Hydrology - River Guidance - Graphical RVF

Location:

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

Issuance Time:

Nov 17 2025 at 2:15 PM PST

Next Issuance:

Nov 18 2025 at 9:00 AM PST

Action/Monitor: 24.5 Feet

Minor Flood: 29.0 Feet

Moderate Flood: 32.0 Feet

Major Flood: 37.3 Feet

Plot Type:

Please Note:
1) Each individual timeseries plotted on the graphical river forecast can be toggled on and off by clicking the legend entry above. If the "Observed (Raw Data)" contains bad data and is toggled off, the plot will scale to the remaining timeseries.

2) At extremely low river flows, the "Observed (Raw Data)" may show readings below the lower end of the available rating table, while the "Observed (Simulated)" will only show values at the bottom of the rating table, creating a potential discrepancy between the two readings.

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 Mean Daily Stage/Flow Data
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2025*	4,9400	12.97	Mar 20, 2025
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
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: Patchy fog in the morning. Partly cloudy. Highs 53 to 61. Light winds becoming southwest up to 10 mph in the afternoon.

Tonight: Partly cloudy. Lows 43 to 49. Light winds.

Wednesday: Partly cloudy in the morning then becoming mostly sunny. Highs 54 to 62. Southeast winds up to 10 mph.

Wednesday Night: Mostly clear in the evening, then mostly cloudy with a chance of rain showers after midnight. Lows 45 to 51. Southeast winds up to 10 mph.

Thursday: Mostly cloudy. Rain showers likely in the morning, then a chance of rain showers in the afternoon. Highs 51 to 58. Southeast winds up to 10 mph.

Thursday Night: Mostly cloudy with a slight chance of rain showers. Lows 41 to 47.

Friday: Partly cloudy. Highs 55 to 61.

Friday Night through Sunday Night: Mostly clear. Lows 40 to 48. Highs 57 to 62.

Monday: Partly cloudy. Highs around 60.

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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