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Big Sioux River near Florence

Highest listed crest 9.70 ftFlood stage 8.0 ft38 crests since 1984

The Big Sioux River near Florence crested at major flood stage 6 times among the 38 crests the National Weather Service lists from 1984 to 2025. The highest, 9.70 ft on April 13, 2023, was major flooding, 1.70 feet above flood stage. 20 other gauges on the Big Sioux River crested above flood stage within a week of it, 1 at its own highest listed crest.

The gauge

Highest listed crest
9.70 ft
April 13, 2023; 2,480 cubic feet per second
Flood stage
8.0 ft
Major flooding from 9.0 ft
Crests at major
6
15th of 155 gauges in South Dakota
Most recent flood crest
June 26, 2025
8.97 ft, moderate flooding
Location
Grant County
South Dakota

Flood stages

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

Flood categories, Big Sioux River near Florence
Action stage7.08Apr 28, 2013The level at which the NWS or its partners begin to take action
Flood stage (minor)8.09Jun 19, 2014Minimal or no property damage, but possibly some public threat
Moderate flood stage8.54Jun 26, 2025Some inundation of structures and roads near the stream
Major flood stage9.06Apr 13, 2023Extensive inundation of structures and roads

Every listed crest

38 crests from 1984 to 2025. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Big Sioux River near Florence, 1984 to 2025 246810ft Flood stage 8.0 ftMajor 9.0 ft Jun 15, 1984: 8.05 ft, minor flooding; 194 cubic feet per secondMar 20, 1985: 7.72 ft, action stage; 268 cubic feet per secondMar 29, 1986: 9.08 ft, major flooding; 1,810 cubic feet per secondMar 25, 1987: 7.51 ft, action stage; 177 cubic feet per secondFeb 28, 1988: 5.62 ft, below flood stage; 14 cubic feet per secondMar 27, 1989: 8.34 ft, minor flooding; 500 cubic feet per secondMay 23, 1990: 4.79 ft, below flood stage; 21 cubic feet per secondAug 2, 1991: 8.16 ft, minor flooding; 287 cubic feet per secondJun 30, 1992: 7.72 ft, action stage; 268 cubic feet per secondJul 25, 1993: 9.18 ft, major flooding; 1,280 cubic feet per secondMar 19, 1994: 8.79 ft, moderate flooding; 1,140 cubic feet per secondMar 11, 1995: 9.02 ft, major flooding; 1,200 cubic feet per secondMar 11, 1996: 7.94 ft, action stage; 387 cubic feet per secondApr 2, 1997: 9.52 ft, major flooding; 2,000 cubic feet per secondMay 16, 1998: 8.12 ft, minor flooding; 528 cubic feet per secondOct 17, 1999: 6.55 ft, below flood stage; 134 cubic feet per secondApr 22, 2000: 3.29 ft, below flood stage; 20 cubic feet per secondApr 7, 2001: 9.07 ft, major flooding; 1,200 cubic feet per secondMar 29, 2002: 7.10 ft, action stage; 110 cubic feet per secondMar 17, 2003: 7.29 ft, action stage; 100 cubic feet per secondJul 10, 2004: 4.78 ft, below flood stage; 54 cubic feet per secondJul 10, 2005: 7.48 ft, action stage; 104 cubic feet per secondMar 30, 2006: 6.60 ft, below flood stage; 131 cubic feet per secondMar 21, 2007: 8.01 ft, minor flooding; 450 cubic feet per secondJun 11, 2008: 8.36 ft, minor flooding; 738 cubic feet per secondMar 17, 2009: 8.50 ft, moderate flooding; 650 cubic feet per secondMar 17, 2010: 8.24 ft, minor flooding; 500 cubic feet per secondApr 4, 2011: 8.45 ft, minor flooding; 850 cubic feet per secondApr 18, 2012: 4.21 ft, below flood stage; 43 cubic feet per secondApr 28, 2013: 7.32 ft, action stage; 200 cubic feet per secondJun 19, 2014: 8.01 ft, minor flooding; 272 cubic feet per secondMar 11, 2015: 5.67 ft, below flood stage; 70 cubic feet per secondApr 26, 2016: 4.09 ft, below flood stage; 39 cubic feet per secondFeb 22, 2017: 6.37 ft, below flood stage; 96 cubic feet per secondMar 27, 2019: 8.95 ft, moderate flooding; 997 cubic feet per secondMay 5, 2020: 6.89 ft, below flood stage; 191 cubic feet per secondApr 13, 2023: 9.70 ft, major flooding; 2,480 cubic feet per secondJun 26, 2025: 8.97 ft, moderate flooding; 554 cubic feet per second Highest, 9.70 ft, Apr 13, 2023 1990200020102020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Big Sioux River near Florence 1980s: 3 1990s: 6 6 2000s: 4 2010s: 4 2020s: 2 1980s1990s2000s2010s2020s
  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.

Highest crests

Highest listed crests, Big Sioux River near Florence
1Apr 13, 20239.70+1.70Major2,480
2Apr 2, 19979.52+1.52Major2,000
3Jul 25, 19939.18+1.18Major1,280
4Mar 29, 19869.08+1.08Major1,810
5Apr 7, 20019.07+1.07Major1,200
6Mar 11, 19959.02+1.02Major1,200
7Jun 26, 20258.97+0.97Moderate554
8Mar 27, 20198.95+0.95Moderate997
9Mar 19, 19948.79+0.79Moderate1,140
10Mar 17, 20098.50+0.50Moderate650
11Apr 4, 20118.45+0.45Minor850
12Jun 11, 20088.36+0.36Minor738
13Mar 27, 19898.34+0.34Minor500
14Mar 17, 20108.24+0.24Minor500
15Aug 2, 19918.16+0.16Minor287
16May 16, 19988.12+0.12Minor528
17Jun 15, 19848.05+0.05Minor194
18Mar 21, 20078.01+0.01Minor450
19Jun 19, 20148.01+0.01Minor272
20Mar 11, 19967.94−0.06Action387
21Mar 20, 19857.72−0.28Action268
22Jun 30, 19927.72−0.28Action268
23Mar 25, 19877.51−0.49Action177
24Jul 10, 20057.48−0.52Action104
25Apr 28, 20137.32−0.68Action200
26Mar 17, 20037.29−0.71Action100
27Mar 29, 20027.10−0.90Action110
28May 5, 20206.89−1.11Below flood stage191
29Mar 30, 20066.60−1.40Below flood stage131
30Oct 17, 19996.55−1.45Below flood stage134
31Feb 22, 20176.37−1.63Below flood stage96
32Mar 11, 20155.67−2.33Below flood stage70
33Feb 28, 19885.62−2.38Below flood stage14
34May 23, 19904.79−3.21Below flood stage21
35Jul 10, 20044.78−3.22Below flood stage54
36Apr 18, 20124.21−3.79Below flood stage43
37Apr 26, 20164.09−3.91Below flood stage39
38Apr 22, 20003.29−4.71Below flood stage20

The worst floods along the Big Sioux River

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

April 13, 2023: 9.70 ft here, major flooding

April 2, 1997: 9.52 ft here, major flooding

March 29, 1986: 9.08 ft here, major flooding

  • CastlewoodSD · Mar 30, 1986 · 11.73 ft · Moderate

Gauges on the Big Sioux River

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

Flood gauges on the Big Sioux River
CantonSD1,235.01,248.35 ft, Jun 22, 20243
Dell RapidsSD1,481.01,490.00 ft, Sep 13, 20192
FlandreauSD1,540.01,545.29 ft, Sep 13, 20191
HawardenSD20.539.92 ft, Jun 22, 20244
AkronIA16.027.35 ft, Jun 22, 202424
FairviewSD1,202.01,213.14 ft, Sep 14, 20190
Lake KampeskaSD21.022.40 ft, Mar 15, 20100
Lake Poinsett Inlet/OutletSD1,654.01,657.60 ft, Apr 5, 20112
Sioux CitySD32.044.90 ft, Jun 23, 20241
Sioux Falls I-90SD12.018.91 ft, Sep 14, 20191
Sioux Falls N. Cliff AvenueSD16.026.08 ft, Sep 14, 20190
Sioux Falls Western AvenueSD8.016.90 ft, Mar 14, 20194
TrentSD1,495.01,501.42 ft, Sep 13, 20192
Watertown Broadway AvenueSD10.513.67 ft, Apr 6, 19971
Watertown Sioux Conifer RoadSD9.011.18 ft, Apr 13, 20230
WatertownSD11.013.13 ft, Apr 2, 19975
BrandonSD1,304.01,313.53 ft, Sep 14, 20192
BrookingsSD9.014.77 ft, Apr 9, 19690
BruceSD8.012.16 ft, Mar 28, 20110
CastlewoodSD9.013.19 ft, Apr 7, 19970
Dell RapidsSD12.016.70 ft, Sep 13, 201910
EganSD1,516.51,524.20 ft, Sep 12, 20192
EstellineSD1,644.01,647.03 ft, Jun 30, 20250
Florence this gaugeSD8.09.70 ft, Apr 13, 20236
JeffersonIA31.044.50 ft, Jun 24, 20242
RichlandIA1,117.01,128.70 ft, Jun 23, 20245
WatertownSD10.012.33 ft, Apr 7, 20012

Other gauges in Grant County

Flood gauges in Grant County
Big Stone Lake970.0973.90 ft, Apr 7, 19971
Big Stone City12.026.00 ft, Jun 1, 19191

Grant County: every hazard · River floods across the country · South Dakota

NOAA National Water Prediction Service, gauge FLOS2, 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.