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Mississippi River at Mel Price (Alton) Lock and Dam

Highest listed crest 42.72 ftFlood stage 21.0 ft71 crests since 1973

The Mississippi River at Mel Price (Alton) Lock and Dam crested at major flood stage 8 times among the 71 crests the National Weather Service lists from 1973 to 2026. The highest, 42.72 ft on August 1, 1993, was major flooding, 21.72 feet above flood stage. 10 other gauges on the Mississippi River crested above flood stage within a week of it, 8 at their own highest listed crest.

The gauge

Highest listed crest
42.72 ft
August 1, 1993; 369,500 cubic feet per second
Flood stage
21.0 ft
Major flooding from 34.0 ft
Crests at major
8
35th of 177 gauges in Illinois
Most recent flood crest
May 1, 2026
24.30 ft, minor flooding
Location
Madison County
Near Alton (2.6 mi), Wood River (3.7 mi), Godfrey (7.2 mi)

Flood stages

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

Flood categories, Mississippi River at Mel Price (Alton) Lock and Dam
Action stage19.00—The level at which the NWS or its partners begin to take action
Flood stage (minor)21.054May 1, 2026Minimal or no property damage, but possibly some public threat
Moderate flood stage29.09Jun 30, 2015Some inundation of structures and roads near the stream
Major flood stage34.08Jun 9, 2019Extensive inundation of structures and roads

Every listed crest

71 crests from 1973 to 2026. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Mississippi River at Mel Price (Alton) Lock and Dam, 1973 to 2026 202530354045ft Flood stage 21.0 ftMajor 34.0 ft Apr 28, 1973: 36.89 ft, major flooding; 535,000 cubic feet per secondJul 30, 1981: 24.90 ft, minor floodingMar 24, 1982: 25.60 ft, minor flooding; 363,000 cubic feet per secondJun 12, 1982: 26.20 ft, minor floodingDec 8, 1982: 32.44 ft, moderate floodingMay 1, 1983: 33.21 ft, moderate floodingApr 25, 1984: 28.10 ft, minor flooding; 305,000 cubic feet per secondJun 28, 1984: 24.30 ft, minor floodingMar 8, 1985: 29.60 ft, moderate flooding; 403,000 cubic feet per secondNov 22, 1985: 27.70 ft, minor floodingMay 23, 1986: 25.90 ft, minor flooding; 308,000 cubic feet per secondOct 9, 1986: 34.20 ft, major floodingApr 18, 1993: 30.80 ft, moderate floodingAug 1, 1993: 42.72 ft, major flooding; 369,500 cubic feet per secondMay 22, 1995: 35.10 ft, major floodingMar 1, 1997: 26.70 ft, minor floodingApr 20, 1997: 25.70 ft, minor floodingApr 18, 1998: 28.10 ft, minor floodingMar 19, 2001: 21.50 ft, minor floodingMay 21, 2001: 25.91 ft, minor floodingJun 9, 2001: 28.90 ft, minor floodingMay 29, 2004: 22.16 ft, minor floodingJan 6, 2005: 22.58 ft, minor flooding; 379,000 cubic feet per secondMay 11, 2007: 22.76 ft, minor floodingMar 21, 2008: 24.44 ft, minor floodingApr 13, 2008: 25.38 ft, minor floodingMay 10, 2008: 24.88 ft, minor floodingMay 28, 2008: 21.02 ft, minor floodingJun 30, 2008: 33.08 ft, moderate floodingAug 1, 2008: 24.06 ft, minor floodingSep 18, 2008: 29.89 ft, moderate floodingMar 16, 2009: 22.66 ft, minor flooding; 381,245 cubic feet per secondApr 1, 2009: 21.73 ft, minor flooding; 347,000 cubic feet per secondMay 21, 2009: 27.24 ft, minor flooding; 278,000 cubic feet per secondJun 20, 2009: 21.55 ft, minor flooding; 343,000 cubic feet per secondNov 2, 2009: 26.31 ft, minor floodingNov 21, 2009: 22.70 ft, minor floodingJan 27, 2010: 21.02 ft, minor floodingMar 29, 2010: 26.61 ft, minor flooding; 453,127 cubic feet per secondApr 28, 2010: 24.03 ft, minor floodingMay 19, 2010: 28.19 ft, minor floodingJun 28, 2010: 29.05 ft, moderate floodingAug 17, 2010: 21.24 ft, minor floodingAug 23, 2010: 21.09 ft, minor floodingApr 30, 2011: 28.28 ft, minor floodingMay 24, 2011: 22.17 ft, minor floodingJun 20, 2011: 27.29 ft, minor floodingApr 25, 2013: 30.62 ft, moderate floodingMay 23, 2013: 21.54 ft, minor floodingJun 4, 2013: 34.38 ft, major floodingJul 11, 2014: 25.84 ft, minor floodingJun 30, 2015: 32.27 ft, moderate floodingDec 19, 2015: 24.01 ft, minor floodingJan 1, 2016: 35.80 ft, major floodingJan 12, 2016: 22.48 ft, minor floodingApr 9, 2017: 22.67 ft, minor floodingMay 6, 2017: 34.86 ft, major floodingOct 16, 2018: 26.78 ft, minor floodingJun 9, 2019: 39.01 ft, major floodingOct 12, 2019: 25.35 ft, minor floodingNov 2, 2019: 21.55 ft, minor floodingJan 13, 2020: 23.33 ft, minor floodingMar 25, 2020: 23.72 ft, minor floodingApr 30, 2020: 22.32 ft, minor floodingMay 19, 2020: 22.16 ft, minor floodingJun 1, 2020: 25.14 ft, minor floodingMar 20, 2021: 25.04 ft, minor floodingApr 14, 2021: 22.90 ft, minor floodingJun 28, 2021: 23.17 ft, minor floodingMay 2, 2024: 23.62 ft, minor floodingMay 1, 2026: 24.30 ft, minor flooding; 419,400 cubic feet per second Highest, 42.72 ft, Aug 1, 1993 19801990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Mississippi River at Mel Price (Alton) Lock and Dam 1970s: 1 1980s: 11 1990s: 6 2000s: 19 2010s: 24 24 2020s: 10 1970s1980s1990s2000s2010s2020s
  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. 1 crest measured on an earlier gauge datum is left out: 36.90 ft on Jun 18, 1844.

Highest crests

The 50 highest of 71 listed crests.

Highest listed crests, Mississippi River at Mel Price (Alton) Lock and Dam
1Aug 1, 199342.72+21.72Major369,500
2Jun 9, 201939.01+18.01Major—
3Apr 28, 197336.89+15.89Major535,000
4Jan 1, 201635.80+14.80Major—
5May 22, 199535.10+14.10Major—
6May 6, 201734.86+13.86Major—
7Jun 4, 201334.38+13.38Major—
8Oct 9, 198634.20+13.20Major—
9May 1, 198333.21+12.21Moderate—
10Jun 30, 200833.08+12.08Moderate—
11Dec 8, 198232.44+11.44Moderate—
12Jun 30, 201532.27+11.27Moderate—
13Apr 18, 199330.80+9.80Moderate—
14Apr 25, 201330.62+9.62Moderate—
15Sep 18, 200829.89+8.89Moderate—
16Mar 8, 198529.60+8.60Moderate403,000
17Jun 28, 201029.05+8.05Moderate—
18Jun 9, 200128.90+7.90Minor—
19Apr 30, 201128.28+7.28Minor—
20May 19, 201028.19+7.19Minor—
21Apr 25, 198428.10+7.10Minor305,000
22Apr 18, 199828.10+7.10Minor—
23Nov 22, 198527.70+6.70Minor—
24Jun 20, 201127.29+6.29Minor—
25May 21, 200927.24+6.24Minor278,000
26Oct 16, 201826.78+5.78Minor—
27Mar 1, 199726.70+5.70Minor—
28Mar 29, 201026.61+5.61Minor453,127
29Nov 2, 200926.31+5.31Minor—
30Jun 12, 198226.20+5.20Minor—
31May 21, 200125.91+4.91Minor—
32May 23, 198625.90+4.90Minor308,000
33Jul 11, 201425.84+4.84Minor—
34Apr 20, 199725.70+4.70Minor—
35Mar 24, 198225.60+4.60Minor363,000
36Apr 13, 200825.38+4.38Minor—
37Oct 12, 201925.35+4.35Minor—
38Jun 1, 202025.14+4.14Minor—
39Mar 20, 202125.04+4.04Minor—
40Jul 30, 198124.90+3.90Minor—
41May 10, 200824.88+3.88Minor—
42Mar 21, 200824.44+3.44Minor—
43Jun 28, 198424.30+3.30Minor—
44May 1, 202624.30+3.30Minor419,400
45Aug 1, 200824.06+3.06Minor—
46Apr 28, 201024.03+3.03Minor—
47Dec 19, 201524.01+3.01Minor—
48Mar 25, 202023.72+2.72Minor—
49May 2, 202423.62+2.62Minor—
50Jan 13, 202023.33+2.33Minor—

The worst floods along the Mississippi River

For this gauge's highest crests, the other gauges on the Mississippi River that crested above flood stage within a week.

August 1, 1993: 42.72 ft here, major flooding

June 9, 2019: 39.01 ft here, major flooding

April 28, 1973: 36.89 ft here, major flooding

Gauges on the Mississippi River

Flood gauges sharing the river's name, linked within 80 miles of one another.

Flood gauges on the Mississippi River
TiptonvilleMO37.048.35 ft, May 5, 20112
Alma - Pool 5MN672.0672.13 ft, Apr 16, 20010
AltonIL21.039.55 ft, Aug 1, 19937
Baton RougeLA35.047.28 ft, May 15, 192731
BellevueIL17.023.51 ft, Apr 26, 196511
BrainerdMN16.017.61 ft, Jun 28, 20120
BrownsvilleMN635.0640.20 ft, Apr 22, 19650
BurlingtonIL15.025.73 ft, Jun 17, 200836
CamancheIA17.024.65 ft, Apr 28, 196520
Canton Lock and Dam 20MO15.027.88 ft, Jul 9, 19933
Cape GirardeauMO32.048.86 ft, Jan 2, 201615
CaruthersvilleMO32.047.61 ft, May 7, 20112
ChesterIL27.049.74 ft, Aug 7, 19939
Clarksville Lock and Dam 24MO25.037.73 ft, Jul 29, 199310
ClaytonIA620.0627.28 ft, Apr 24, 19650
DakotaMN644.0649.08 ft, Apr 21, 19650
DonaldsonvilleLA27.036.01 ft, May 15, 19273
Dubuque (LD11)IA16.025.69 ft, Apr 26, 196513
Dubuque (Railroad Bridge)IA17.026.81 ft, Apr 26, 196518
Fort RipleyMN10.514.15 ft, Apr 8, 19970
Fridley abv 37th Ave NEMN16.020.00 ft, Apr 17, 19656
FultonIL16.024.75 ft, Apr 28, 196513
GladstoneIL10.022.46 ft, Jun 17, 200824
GraftonIL20.038.17 ft, Aug 1, 199315
Gregory LandingMO15.028.49 ft, Jul 9, 19934
HannibalMO17.031.80 ft, Jul 15, 199310
HelenaAR44.060.21 ft, Feb 12, 19374
HerculaneumMO26.029.79 ft, Jul 10, 20240
HickmanKY34.054.29 ft, May 2, 20113
Hwy 169 at ChamplinMN12.017.96 ft, Apr 12, 19653
Hwy 610 in Brooklyn ParkMN12.019.53 ft, Apr 17, 19654
Illinois CityIA15.024.10 ft, Jul 9, 199321
KeithsburgIA14.024.49 ft, Jun 17, 200822
KeokukIA16.027.58 ft, Jul 10, 199324
La Crosse - Pool 8WI12.017.89 ft, Apr 22, 19654
LaGrangeMO17.030.00 ft, Jul 13, 19934
Lake CityWI16.022.18 ft, Apr 19, 19653
Lansing - Pool 9IA17.022.50 ft, Apr 24, 19651
LeClaireIA11.017.75 ft, Apr 28, 196516
LouisianaMO15.028.40 ft, Jul 28, 19934
McGregorIA16.025.38 ft, Apr 24, 19653
Mel Price (Alton) Lock and Dam this gaugeIL21.042.72 ft, Aug 1, 19938
MemphisTN34.048.70 ft, Feb 10, 19372
MuscatineIA16.025.61 ft, Jul 9, 199321
NatchezMS48.061.95 ft, May 19, 20116
New BostonIL15.025.90 ft, Jul 9, 199322
New MadridMO34.048.35 ft, May 6, 20114
New OrleansLA17.021.27 ft, Apr 25, 19225
OsceolaAR28.050.90 ft, Feb 7, 193742
QuincyIL19.032.13 ft, Jul 13, 19937
Quincy Lock and Dam 21IL18.031.30 ft, Jul 13, 19937
Red River LandingLA48.063.39 ft, May 18, 20110
Red WingMN14.020.70 ft, Apr 18, 19659
ReserveLA22.026.00 ft, Jun 11, 19291
Rock IslandIL15.022.70 ft, May 2, 201920
Saverton Lock and Dam 22MO16.029.58 ft, Jul 25, 19939
St. CloudMN9.011.44 ft, Apr 8, 19971
St. LouisMO30.049.58 ft, Aug 1, 19939
St. PaulMN14.026.01 ft, Apr 16, 196516
ThebesIL33.047.74 ft, Jan 2, 201612
Tunica Mhoon LandingMS30.053.20 ft, Feb 10, 19375
VicksburgLA43.057.10 ft, May 19, 201112
Wabasha - Pool 4MN12.020.05 ft, Apr 19, 19657
Winfield Lock and Dam 25MO26.039.62 ft, Aug 1, 19939
Winona - Pool 6MN13.020.77 ft, Apr 19, 19655
Lock and Dam 10 - GuttenbergIA15.023.65 ft, Apr 24, 19652
Lock and Dam 2 - HastingsMN15.025.90 ft, Apr 17, 196512
Lock and Dam 3 - Red WingMN680.5687.77 ft, Apr 19, 19658
Lock and Dam 4 - AlmaWI16.019.78 ft, Apr 19, 19652
Lock and Dam 5 - Minnesota CityMN660.0667.85 ft, Apr 19, 19654
Lock and Dam 5a - WinonaMN655.0663.35 ft, Apr 19, 19654
Lock and Dam 6 - TrempealeauMN647.0653.02 ft, Apr 21, 19654
Lock and Dam 7 - La CrescentMN641.0647.38 ft, Apr 21, 19652
Lock and Dam 8 - GenoaWI631.0638.40 ft, Apr 22, 19653
Lock and Dam 9 - LynxvilleWI625.0633.16 ft, Apr 24, 19653
AitkinMN13.022.49 ft, May 20, 195011
Arkansas CityAR37.059.20 ft, Apr 21, 192715
GreenvilleAR48.065.40 ft, Apr 21, 192718

Other gauges in Madison County

Flood gauges in Madison County
Alton21.039.55 ft, Aug 1, 19937

Madison County: every hazard · River floods across the country · Illinois

NOAA National Water Prediction Service, gauge ALNI2, 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.