Rivers in Iowa

Big Sioux River above Hawarden

Sioux County, IowaNWS HWDI4USGS 06483950Sioux Falls office

Below flood stage
13.26ftStage

Observed Thu, Sep 24, 4:30 AM CDT

Flood stage
20.50 ft
Record crest
39.92 ft2024

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood30.00 ft
Moderate flood24.00 ft
Minor flood20.50 ft
Action18.50 ft
  1. 39.00 ftSignificant flooding continues in Hawarden with roughly the western half of the town flooded.
  2. 35.00 ftWater overtops 10th St and floods the lower portions of Hawarden south of 10th St and west of Highway 10.
  3. 34.00 ftSeveral structures near the river off of 10th St in Haward are flooded or surrounded by water.
  4. 32.00 ftWater backs up into the park in Hawarden, and some basements and sewers could begin to have problems.
  5. 30.50 ftIowa Highway 10 begins to flood.
  6. 30.00 ftSouth Dakota Highway 46 begins to flood north of Hawarden.
  7. 29.50 ftCounty Road 13 begins to flood west of Hawarden. The lowest campsites at the Big Sioux Recreation Area are flooded.
  8. 27.50 ftRiver Road between 304th St and County Road 13 begins to flood.
  9. 25.50 ftWater may begin to backup the drainage ditches into the lakes at the Big Sioux Recreation Area in Hawarden.
  10. 24.00 ftSome farm houses on the South Dakota side of the river are isolated by high water.
  11. 20.50 ftAgricultural flooding begins on the South Dakota side of the river.

Flood outlook

Chance of flooding, September to November

CategoryChance
Minor flooding18%
Moderate flooding5%
Major floodingUnder 5%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued September 23, 2026.

Crest history

12 crests on NOAA’s list since 2015.

#DateStage
1June 22, 202439.92 ft
2March 15, 201935.20 ft
3June 22, 201834.00 ft
4September 15, 201932.42 ft
5March 30, 202023.02 ft
6April 13, 202322.89 ft
7May 2, 201622.38 ft
8May 23, 201720.35 ft
9June 1, 202218.88 ft
10July 9, 201518.30 ft
11August 30, 202117.30 ft
12July 6, 202516.39 ft

Most recent crests

  • July 6, 2025: 16.39 ft
  • June 22, 2024: 39.92 ft
  • April 13, 2023: 22.89 ft
  • June 1, 2022: 18.88 ft
  • August 30, 2021: 17.30 ft
  • March 30, 2020: 23.02 ft
  • September 15, 2019: 32.42 ft
  • March 15, 2019: 35.20 ft
  • June 22, 2018: 34.00 ft
  • May 23, 2017: 20.35 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 48 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 24 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.