Big Sioux River at Sioux Falls Maple Street, SD
River level and flood forecast · Minnehaha County
Normal3.1 ftas of Mon 3:30 PM
The river is 11.9 ft below flood stage (15 ft).
The last 7 days and the forecast
NWS forecast issued Sun, Dec 31, 6 PM. Forecasts change as rain falls and as upstream water arrives.
Flood stages
| Major flood stage | 21 ft |
| Moderate flood stage | 18 ft |
| Flood stage | 15 ft |
| Action stage | 14 ft |
| Record crest (June 22, 2024) | 9.75 ft |
What floods at each level
From the National Weather Service, highest first.
- 19 ftWater overtops the walk bridge near the gage.
- 18 ftWater reaches the bottom of the walk bridge near the gage.
- 17 ftWater reaches the low steel on the walk bridge near the gage.
- 15 ftWater reaches the bottom of the levees. If there is a levee failure, flooding in Sioux Falls could occur.
Highest crests on record
- 9.75 ft — June 22, 2024
- 9.2 ft — March 25, 2019
- 7.59 ft — May 17, 2007
- 7.59 ft — May 25, 2022
- 7.24 ft — June 15, 2014
Recent crests: 5.22 ft (August 27, 2025) · 9.75 ft (June 22, 2024) · 6.49 ft (April 24, 2023) · 7.59 ft (May 25, 2022) · 6.48 ft (April 27, 2021)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (SFMS2); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.