Little Sioux River at Linn Grove, IA
River level and flood forecast · Buena Vista County
Normal5.9 ftas of Mon 4 PM
The river is 10.6 ft below flood stage (16.5 ft).
Flow: 310 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 | 22.5 ft |
| Moderate flood stage | 20 ft |
| Flood stage | 16.5 ft |
| Action stage | 14 ft |
| Record crest (June 23, 2024) | 29.98 ft |
What floods at each level
From the National Weather Service, highest first.
- 31.5 ftWeaver St is flooded in Linn Grove.
- 29 ftSignificant flooding is ongoing in Sioux Rapids as water reaches as far in as 2nd and Main St. Water also reaches the bottom of the bridge on Weaver St in Linn Grove.
- 28 ftHighway 71 south of the bridge in Sioux Rapids is flooded and at least one house in Linn Grove near the campground may flood.
- 27 ftThe bathroom at the campground in Linn Grove floods.
- 24 ftSome businesses west of Hwy 71 in Sioux Rapids are in danger of flooding. The low portion of Highway 71 north of the bridge in Sioux Rapids may begin to flood.
- 22.5 ftPark St, as well as the northern portion of 1st St in Sioux Rapids begin to flood.
- 21 ftThe lowest campsites at the campground in Linn Grove begin to flood.
- 20 ftSignificant flooding of agricultural land begins along this entire stretch of the river. Water begins to flood the lower road at the campground in Linn Grove.
- 16.5 ftMore substantial flooding of agricultural land as well as the park in Sioux Rapids begins
- 14 ftWater begins to overtop the lowest banks as well as spill in the lowest areas of the park in Sioux Rapids.
Highest crests on record
- 29.98 ft — June 23, 2024
- 24.13 ft — March 16, 2019
- 23.91 ft — September 22, 2018
- 22.91 ft — June 18, 2014
- 22.85 ft — March 17, 2010
Recent crests: 12.87 ft (August 2, 2025) · 29.98 ft (June 23, 2024) · 13.9 ft (May 18, 2023) · 7.76 ft (March 9, 2021) · 15.72 ft (May 29, 2020)
Up and down the river, and nearby
Not an official source. River levels, forecasts, flood stages and impacts are from the National Weather Service (LNNI4); flow from the U.S. Geological Survey. Readings are provisional. In a flood, follow your local officials and the NWS at weather.gov.