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.

SAN JOAQUIN RIVER - PATTERSON (PATC1)

Latitude: 37.49º N	Longitude: 121.08º W	Elevation: 97 Feet
Location: Stanislaus County in California		Bulletin Group: San Joaquin		River Group: San Joaquin

Action/Monitor: 48.0 Feet

Minor Flood: 54.7 Feet

Moderate Flood: 57.3 Feet

Major Flood: 58.3 Feet

Plot Type:

Observed Data Credit
	Raw streamflow data is provided by the California Department of Water Resources. View California Department of Water Resources Data for this station location.

Historical Stage/Flow Data
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2024	5,740	41.64	Mar 7, 2024
2023	24,500	52.24	Mar 27, 2023
2022	1,190	33.41	Dec 31, 2021
2021	1,770	34.50	Feb 1, 2021
2020	3,120	37.40	Oct 2, 2019
Historical High Stage/Flow Events (Period of Record - Oct 1969 to Present) - Ranked by Flow
1983*	28,700	51.26	Mar 4, 1983
2006*	27,612	50.97	Apr 10, 2006
2017	25,600	51.71	Feb 22, 2017
1980*	24,900	50.57	Feb 25, 1980
2023	24,500	52.24	Mar 27, 2023
1938*	--	50.50	Jun 13, 1938
1986*	23,000	49.65	Mar 18, 1986

* Discharge affected by regulation or diversion
** Most recent continuous record back to Oct 1969 with segmented periods back to Apr 1938

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Flood Impacts
58.3 Feet	Stages above 58.3 feet result in flooding outside the levee. Top of levee.

Official 7 Day National Weather Service Forecast (CAZ019)

Today: Mostly sunny. Highs 82 to 90. Northwest winds up to 10 mph.

Tonight: Clear. Lows 50 to 58. Northwest winds up to 10 mph with gusts to around 20 mph.

Sunday: Mostly sunny. Highs 85 to 93. Northwest winds up to 10 mph.

Sunday Night: Clear. Lows 50 to 58. Northwest winds up to 15 mph.

Monday: Sunny. Highs 82 to 90. Northwest winds up to 10 mph with gusts to around 20 mph.

Monday Night: Clear. Lows 51 to 57.

Tuesday: Sunny. Highs 86 to 94.

Tuesday Night through juneteenth: Clear. Lows 54 to 62. Highs 87 to 97.

Thursday Night and Friday: Clear. Lows 51 to 57. Highs 82 to 92.

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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