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San Joaquin River at Vernalis

Highest listed crest 34.88 ftFlood stage 29.0 ft56 crests since 1950

The San Joaquin River at Vernalis crested above flood stage 8 times among the 56 crests the National Weather Service lists from 1950 to 2026. The highest, 34.88 ft on January 5, 1997, was moderate flooding, 5.88 feet above flood stage.

The gauge

Highest listed crest
34.88 ft
January 5, 1997; 75,600 cubic feet per second
Flood stage
29.0 ft
Major flooding from 37.3 ft
Crests at major
0
8 above flood stage
Most recent flood crest
March 19, 2023
29.83 ft, minor flooding
Location
San Joaquin County
Near Manteca (8.4 mi), Ripon (8.7 mi), Lathrop (9.6 mi)

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, San Joaquin River at Vernalis
Action stage24.55Jan 18, 2023The level at which the NWS or its partners begin to take action
Flood stage (minor)29.06Mar 19, 2023Minimal or no property damage, but possibly some public threat
Moderate flood stage32.02Jan 5, 1997Some inundation of structures and roads near the stream
Major flood stage37.30—Extensive inundation of structures and roads

Every listed crest

56 crests from 1950 to 2026. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the San Joaquin River at Vernalis, 1950 to 2026 010203040ft Flood stage 29.0 ftMajor 37.3 ft Dec 9, 1950: 32.81 ft, moderate flooding; 79,000 cubic feet per secondDec 25, 1955: 21.83 ft, below flood stage; 50,900 cubic feet per secondDec 23, 1970: 15.30 ft, below flood stageDec 30, 1971: 12.50 ft, below flood stageFeb 18, 1973: 20.40 ft, below flood stageJan 27, 1974: 17.90 ft, below flood stageFeb 15, 1975: 17.40 ft, below flood stageOct 19, 1975: 14.30 ft, below flood stageOct 2, 1977: 9.00 ft, below flood stageMay 4, 1978: 26.90 ft, action stageMar 3, 1979: 20.90 ft, below flood stageJan 31, 1981: 14.40 ft, below flood stage; 3,850 cubic feet per secondApr 18, 1982: 29.12 ft, minor flooding; 28,100 cubic feet per secondJan 6, 1984: 29.00 ft, minor flooding; 30,700 cubic feet per secondDec 20, 1985: 14.50 ft, below flood stage; 4,650 cubic feet per secondMar 18, 1986: 29.80 ft, minor flooding; 34,000 cubic feet per secondMar 6, 1987: 11.20 ft, below flood stage; 1,850 cubic feet per secondApr 27, 1988: 11.10 ft, below flood stage; 1,800 cubic feet per secondMay 3, 1989: 10.90 ft, below flood stage; 1,650 cubic feet per secondMay 29, 1990: 10.20 ft, below flood stage; 1,200 cubic feet per secondJan 19, 1993: 18.30 ft, below flood stage; 10,300 cubic feet per secondJan 29, 1995: 19.49 ft, below flood stage; 11,830 cubic feet per secondFeb 10, 1995: 11.25 ft, below flood stage; 2,880 cubic feet per secondMar 20, 1995: 26.77 ft, action stage; 26,013 cubic feet per secondJan 5, 1997: 34.88 ft, moderate flooding; 75,600 cubic feet per secondFeb 13, 1998: 28.66 ft, action stageFeb 14, 1999: 20.88 ft, below flood stageFeb 26, 2001: 13.49 ft, below flood stageJan 4, 2002: 13.94 ft, below flood stageApr 21, 2003: 11.27 ft, below flood stageFeb 27, 2004: 12.20 ft, below flood stageJan 5, 2005: 13.12 ft, below flood stageJun 2, 2005: 20.73 ft, below flood stageMar 2, 2006: 12.06 ft, below flood stageApr 13, 2006: 29.25 ft, minor floodingJan 29, 2008: 13.50 ft, below flood stageMar 6, 2009: 11.02 ft, below flood stageJan 24, 2010: 12.71 ft, below flood stageApr 2, 2011: 27.17 ft, action stageMay 14, 2012: 12.95 ft, below flood stageMay 4, 2013: 12.37 ft, below flood stageApr 27, 2014: 11.13 ft, below flood stageDec 14, 2014: 9.66 ft, below flood stageApr 26, 2015: 9.66 ft, below flood stageMar 15, 2016: 14.21 ft, below flood stageFeb 23, 2017: 30.72 ft, minor floodingApr 8, 2018: 17.83 ft, below flood stageMar 4, 2019: 21.84 ft, below flood stageDec 9, 2019: 14.29 ft, below flood stage; 6,130 cubic feet per secondJan 31, 2021: 10.76 ft, below flood stage; 2,470 cubic feet per secondDec 29, 2021: 10.83 ft, below flood stage; 2,600 cubic feet per secondJan 18, 2023: 25.70 ft, action stageMar 19, 2023: 29.83 ft, minor floodingMar 6, 2024: 18.12 ft, below flood stageMar 20, 2025: 13.03 ft, below flood stageFeb 21, 2026: 16.01 ft, below flood stage Highest, 34.88 ft, Jan 5, 1997 19501960197019801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, San Joaquin River at Vernalis 1950s: 1 1960s: 0 1970s: 0 1980s: 3 3 1990s: 1 2000s: 1 2010s: 1 2020s: 1 1950s1960s1970s1980s1990s2000s2010s2020s
  1. These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
  2. Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.
  3. 10 crests measured on an earlier gauge datum are left out: 32.11 ft on Feb 12, 1938; 32.71 ft on Mar 16, 1938; 30.43 ft on Apr 2, 1940; 20.40 ft on May 31, 1963; 12.60 ft on Dec 27, 1963; 25.50 ft on Jan 12, 1965; and more.

Highest crests

The 50 highest of 56 listed crests.

Highest listed crests, San Joaquin River at Vernalis
1Jan 5, 199734.88+5.88Moderate75,600
2Dec 9, 195032.81+3.81Moderate79,000
3Feb 23, 201730.72+1.72Minor—
4Mar 19, 202329.83+0.83Minor—
5Mar 18, 198629.80+0.80Minor34,000
6Apr 13, 200629.25+0.25Minor—
7Apr 18, 198229.12+0.12Minor28,100
8Jan 6, 198429.000.00Minor30,700
9Feb 13, 199828.66−0.34Action—
10Apr 2, 201127.17−1.83Action—
11May 4, 197826.90−2.10Action—
12Mar 20, 199526.77−2.23Action26,013
13Jan 18, 202325.70−3.30Action—
14Mar 4, 201921.84−7.16Below flood stage—
15Dec 25, 195521.83−7.17Below flood stage50,900
16Mar 3, 197920.90−8.10Below flood stage—
17Feb 14, 199920.88−8.12Below flood stage—
18Jun 2, 200520.73−8.27Below flood stage—
19Feb 18, 197320.40−8.60Below flood stage—
20Jan 29, 199519.49−9.51Below flood stage11,830
21Jan 19, 199318.30−10.70Below flood stage10,300
22Mar 6, 202418.12−10.88Below flood stage—
23Jan 27, 197417.90−11.10Below flood stage—
24Apr 8, 201817.83−11.17Below flood stage—
25Feb 15, 197517.40−11.60Below flood stage—
26Feb 21, 202616.01−12.99Below flood stage—
27Dec 23, 197015.30−13.70Below flood stage—
28Dec 20, 198514.50−14.50Below flood stage4,650
29Jan 31, 198114.40−14.60Below flood stage3,850
30Oct 19, 197514.30−14.70Below flood stage—
31Dec 9, 201914.29−14.71Below flood stage6,130
32Mar 15, 201614.21−14.79Below flood stage—
33Jan 4, 200213.94−15.06Below flood stage—
34Jan 29, 200813.50−15.50Below flood stage—
35Feb 26, 200113.49−15.51Below flood stage—
36Jan 5, 200513.12−15.88Below flood stage—
37Mar 20, 202513.03−15.97Below flood stage—
38May 14, 201212.95−16.05Below flood stage—
39Jan 24, 201012.71−16.29Below flood stage—
40Dec 30, 197112.50−16.50Below flood stage—
41May 4, 201312.37−16.63Below flood stage—
42Feb 27, 200412.20−16.80Below flood stage—
43Mar 2, 200612.06−16.94Below flood stage—
44Apr 21, 200311.27−17.73Below flood stage—
45Feb 10, 199511.25−17.75Below flood stage2,880
46Mar 6, 198711.20−17.80Below flood stage1,850
47Apr 27, 201411.13−17.87Below flood stage—
48Apr 27, 198811.10−17.90Below flood stage1,800
49Mar 6, 200911.02−17.98Below flood stage—
50May 3, 198910.90−18.10Below flood stage1,650

Other gauges in San Joaquin County

Flood gauges in San Joaquin County
Benson's Ferry17.020.56 ft, Feb 11, 20172

San Joaquin County: every hazard · River floods across the country · California

NOAA National Water Prediction Service, gauge VNSC1, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.