Big Sioux River near Watertown
Observed Thu, Sep 24, 5:00 PM CDT
- Flood stage
- 10.00 ft
- Record crest
- 12.33 ft2001
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 12.00 ft |
| Moderate flood | 11.00 ft |
| Minor flood | 10.00 ft |
| Action | 9.00 ft |
- 20.00 ftThe bridge at the gaging location is overtopped
- 19.00 ftThe bridge 1 mile south of the gage is overtopped
- 16.00 ftThe water reaches the bottom of the bridge at the gage and the bridge 1 mile south of the gage
- 13.00 ftFlooding begins to affect the city of watertown and the sidewalk on the highway 81 bridge is overtopped
- 12.50 ftCounty roads begin to flood
- 11.50 ftSignificant amounts of pasture and crop land are flooded
- 9.00 ftThe lowest banks are overtopped and minimal areas of pasture land will be flooded
Flood outlook
Chance of flooding, September to November
| Category | Chance |
|---|---|
| Minor flooding | Under 5% |
| Moderate flooding | Under 5% |
| Major flooding | Under 5% |
The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 23, 2026.
Crest history
49 crests on NOAA’s list since 1973.
| # | Date | Stage |
|---|---|---|
| 1 | April 7, 2001 | 12.33 ft |
| 2 | April 5, 1997 | 12.09 ft |
| 3 | April 13, 2023 | 11.85 ft |
| 4 | March 28, 2019 | 11.21 ft |
| 5 | June 21, 1991 | 11.13 ft |
| 6 | March 30, 1986 | 11.08 ft |
| 7 | March 30, 1978 | 11.07 ft |
| 8 | March 28, 1993 | 11.07 ft |
| 9 | March 14, 1996 | 10.67 ft |
| 10 | March 15, 2010 | 10.66 ft |
| 11 | August 6, 2025 | 10.61 ft |
| 12 | March 23, 2011 | 10.30 ft |
| 13 | May 31, 2022 | 10.11 ft |
| 14 | March 20, 1994 | 9.86 ft |
| 15 | April 13, 1979 | 9.82 ft |
| 16 | March 22, 2007 | 9.82 ft |
| 17 | June 19, 2014 | 9.82 ft |
| 18 | March 12, 1995 | 9.81 ft |
| 19 | March 17, 1985 | 9.62 ft |
| 20 | June 16, 1984 | 9.25 ft |
| 21 | October 23, 2019 | 9.08 ft |
| 22 | March 27, 1989 | 8.98 ft |
| 23 | March 30, 1982 | 8.97 ft |
| 24 | March 29, 2002 | 8.97 ft |
| 25 | April 28, 2013 | 8.89 ft |
Most recent crests
- August 6, 2025: 10.61 ft
- April 13, 2023: 11.85 ft
- May 31, 2022: 10.11 ft
- April 10, 2021: 7.12 ft
- October 23, 2019: 9.08 ft
- March 28, 2019: 11.21 ft
- September 25, 2017: 7.88 ft
- April 27, 2016: 4.82 ft
- March 11, 2015: 7.85 ft
- June 19, 2014: 9.82 ft
Nearby
Upstream, downstream and the gauges around this one.
- UpstreamBig Sioux River at Florence
- DownstreamBig Sioux River at Lake Kampeska
- Mud Creek at Rauville
- Big Sioux River at Watertown Sioux Conifer Road
- South Branch Tributary Mud Creek at Rauville
- Lake Kampeska at Watertown Water Plant
- Big Sioux River at Watertown Broadway Avenue
- Willow Creek at Watertown
- Pelican Lake at Watertown
What this means
Forecasts by the Missouri Basin River Forecast Center. Forecasts are issued as needed during times of high water, but are not routinely available. River forecasts for this location take into account past precipitation and the precipitation amounts expected approximately 24 hours into the future from the forecast issuance time. River forecasts for this location take into account past precipitation and the precipitation amounts expected approximately 48 hours into the future from the forecast issuance time. Gauge reading may be affected by ice.
Sources
Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service. Streamflow and the daily record from the U.S. Geological Survey.