Big Sioux River near Brookings
Observed Wed, Sep 23, 2:45 PM CDT
- Flood stage
- 9.00 ft
- Record crest
- 14.77 ft1969
Flood stages and impacts
| Category | Stage |
|---|---|
| Major flood | 15.00 ft |
| Moderate flood | 10.50 ft |
| Minor flood | 9.00 ft |
| Action | 8.00 ft |
- 16.00 ftThe bridges on 473rd Avenue and 475th Avenue are overtopped.
- 14.00 ftThe water reaches the bottom of the bridges on 473rd Avenue and 475th Avenue.
- 13.00 ft223rd St west of the bridge begins to flood. The bridge 1 mile south of Medary on 471st Avenue is overtopped.
- 12.00 ft475th Avenue and 222nd Street begin to flood.
- 11.50 ft473rd Avenue at 221st Street begins to flood.
- 11.00 ftSome farm outbuildings begin to flood.
- 10.50 ft473rd Avenue north of the gauge begins to flood.
- 10.00 ftFlooding begins to affect agricultural lands along the right bank of the river.
- 9.00 ftSignificant amounts of pasture and farm lands begin flooding on the left bank of the river. The road south of the Brookings water treatment plant is flooded, as is 217th Street between 468th and 469th Avenues.
- 8.00 ftThere is some minor overflow of the lowest banks along this stretch of the river.
Flood outlook
Chance of flooding, September to November
| Category | Chance |
|---|---|
| Minor flooding | 6% |
| 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
73 crests on NOAA’s list since 1954.
| # | Date | Stage |
|---|---|---|
| 1 | April 9, 1969 | 14.77 ft |
| 2 | September 13, 2019 | 14.34 ft |
| 3 | June 22, 1984 | 13.70 ft |
| 4 | September 25, 2010 | 13.66 ft |
| 5 | July 4, 1993 | 13.50 ft |
| 6 | March 24, 2011 | 13.33 ft |
| 7 | April 8, 1997 | 13.19 ft |
| 8 | March 25, 2019 | 13.05 ft |
| 9 | March 29, 1962 | 12.95 ft |
| 10 | September 20, 1986 | 12.63 ft |
| 11 | March 19, 1985 | 12.51 ft |
| 12 | April 6, 1965 | 12.34 ft |
| 13 | April 24, 2018 | 12.30 ft |
| 14 | June 20, 1992 | 12.28 ft |
| 15 | March 30, 1960 | 12.28 ft |
| 16 | March 15, 2007 | 12.09 ft |
| 17 | June 25, 1994 | 12.08 ft |
| 18 | June 25, 1980 | 11.93 ft |
| 19 | April 20, 1995 | 11.90 ft |
| 20 | March 29, 1978 | 11.84 ft |
| 21 | April 14, 1979 | 11.71 ft |
| 22 | April 24, 2001 | 11.69 ft |
| 23 | June 17, 1957 | 11.67 ft |
| 24 | March 13, 1966 | 11.66 ft |
| 25 | March 15, 1971 | 11.50 ft |
Most recent crests
- July 3, 2025: 10.41 ft
- June 27, 2024: 11.06 ft
- April 14, 2023: 11.16 ft
- May 14, 2022: 7.09 ft
- April 11, 2021: 6.37 ft
- March 12, 2020: 11.05 ft
- September 13, 2019: 14.34 ft
- March 25, 2019: 13.05 ft
- April 24, 2018: 12.30 ft
- May 25, 2017: 7.40 ft
Nearby
Upstream, downstream and the gauges around this one.
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.