CNRFC - Hydrology - River Guidance - Graphical RVF

Location:

MORMON SLOUGH - BELLOTA (MSGC1)

Latitude: 38.05º N	Longitude: 121.01º W	Elevation: 130 Feet
Location: San Joaquin County in California		Bulletin Group: San Joaquin		River Group: North San Joaquin

Issuance Time:

Dec 13 2025 at 7:01 AM PST

Next Issuance:

Dec 14 2025 at 9:00 AM PST

Action/Monitor: 16.0 Feet

Minor Flood: 22.0 Feet

Moderate Flood: 30.9 Feet

Major Flood: 31.9 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 Army Corps of Engineers. View US Army Corps of Engineers Data for this station location.

Historical Mean Daily Stage/Flow Data
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2025*	904	6.89	Feb 15, 2025
2024*	1,100	7.44	Mar 3, 2024
2023*	11,400	21.80	Jan 16, 2023
2022*	1,950	9.21	Oct 25, 2021
2021*	839	6.78	Jan 28, 2021
Historical High Stage/Flow Events (Period of Record - Dec 1997 to Present) - Ranked by Flow
2023*	11,400	21.80	Jan 16, 2023
1998*	9,395	18.48	Feb 3, 1998
2006*	9,328	18.40	Apr 4, 2006
2011*	8,354	17.22	Mar 24, 2011
* Discharge affected by regulation or diversion

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Flood Impacts
31.9 Feet	Top of Levee right bank levee. Water will overflow toward Bellota and Highway 26.
23.0 Feet	Danger Stage
22.0 Feet	Flood Stage
16.0 Feet	Monitor Stage - Bike trail within lower Calaveras River channel flooded.
14.2 Feet	UOP research within the Calaveras River channel is affected by water levels.
9.0 Feet	Water rises out of the pilot channel but not yet on the levee slopes.

Official 7 Day National Weather Service Forecast (CAZ019)

Today: Mostly cloudy. Areas of fog and locally dense until late afternoon. Patchy fog late in the afternoon. Highs 47 to 57. Light winds.

Tonight: Mostly cloudy. Patchy fog in the evening. Areas of dense fog and locally dense after midnight. Lows 39 to 45. Light winds.

Sunday: Areas of fog and locally dense in the morning. Mostly cloudy. Highs 46 to 56. Light winds.

Sunday Night: Partly cloudy. Lows 40 to 46. Light winds.

Monday: Mostly cloudy. Highs 50 to 60. Light winds.

Monday Night: Mostly cloudy. Lows 43 to 49.

Tuesday: Mostly cloudy. Highs 56 to 62.

Tuesday Night and Wednesday: Mostly cloudy with a chance of rain showers. Lows around 53. Highs around 61.

Wednesday Night and Thursday: Mostly cloudy with a slight chance of rain showers. Lows around 47. Highs around 57.

Thursday Night and Friday: Mostly cloudy with a chance of rain showers. Lows around 49. Highs around 56.

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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