Big Sioux River near Dell Rapids, SD
River level and flood forecast · Minnehaha County
Normal3.3 ftas of Mon 2:30 PM
The river is 8.7 ft below flood stage (12 ft).
Flow: 131 cubic feet per second (USGS).
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 | 15 ft |
| Moderate flood stage | 14 ft |
| Flood stage | 12 ft |
| Action stage | 10 ft |
| Record crest (September 13, 2019) | 16.7 ft |
What floods at each level
From the National Weather Service, highest first.
- 22 ftThe bridge on 250th Street just west of Baltic is overtopped.
- 21 ftThe bridge at the gauge on 248th St is overtopped and several outbuildings near the gauge are flooded.
- 17.5 ftWater reaches the bottom of the bridge on 250th Street west of Baltic.
- 16.5 ftMuch of the area between the railroad on the north bank of the river and about 250 yards north of Centennial Pl on the south bank is flooded resulting in significant impacts. Water reaches the bottom of the bridge on 254th St.
- 16 ft248th Street east of the gauge is flooded, along with several other county roads. Flooding will affect the city of Renner with water going over the main road in town.
- 15.5 ftSignificant flooding is ongoing south of the railroad track in Dell Rapids on the north bank of the river with significant flooding of the athletic fields and campground on the south bank. County Road 130 in Renner is flooded.
- 15 ftSeveral homes and businesses south of the railroad track in Dell Rapids begin to flood. Some homes in Renner are flooded.
- 14.5 ft250th St west of Baltic begins to flood, River Park Road in Baltic is flooded, and a couple of homes and outbuildings west of 1st Avenue in Baltic are in danger of flooding. Portions of Garfield Ave in Dell Rapids south of the bridge may begin to flood.
- 14 ftSignificant amounts of agricultural lands are flooded through the basin, and River Park in Baltic begins to flood.
- 12 ftThe city parks and athletic fields in Dell Rapids begin to flood. Water approaches at least one outbuilding in Dell Rapids along the river. Agricultural land flooding also begins to increase in coverage.
- 10 ftThe lowest banks begin to be overtopped. The bike trail under the Garfield Ave bridge in Dell Rapids begins to flood.
Highest crests on record
- 16.7 ft — September 13, 2019
- 16.47 ft — April 9, 1969
- 16.29 ft — September 25, 2010
- 16.02 ft — March 15, 2007
- 15.69 ft — March 24, 2019
Recent crests: 10.59 ft (July 5, 2025) · 13.84 ft (June 24, 2024) · 12.9 ft (April 10, 2023) · 9.56 ft (May 13, 2022) · 7.32 ft (April 13, 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 (DERS2); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.