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Big Sioux River at Sioux City water level

River gauge, Big Sioux River, Iowa, United States

Directions

Very low for mid-October

Water level

9.95ft Down 0.08 ft over the last 24 hours

13 25 38 Highest onrecord 44.90 ft Minor floodstage 32.00 ft

History

102030ftOct 16Oct 17Oct 18Oct 19Oct 20Minor flood stage102030ftOct 16Oct 18Oct 20Minor flood stage
102030ftSep 21Sep 28Oct 5Oct 13Oct 20Minor flood stage102030ftSep 21Oct 5Oct 20Minor flood stage
102030ftOct 2025Jan 2026Apr 2026Jul 2026Oct 2026Minor flood stage102030ftOct 2025Apr 2026Oct 2026Minor flood stage
102030ftJanMarMayJulSepNov2026102030ftJanAprJulOct2026

20252026

Water level Normal range (10–90 %) Minor flood stage

What this means

Low water at Big Sioux River at Sioux City: the gauge reads 9.95 ft, far below normal for mid-October.

The median for mid-October is 11.56 ft, based on 9 years of readings, so the river stage is 1.61 ft below typical. It is 22.05 ft below the flood stage of 32.00 ft. On the same day last year the reading was 10.02 ft, a difference of −0.07 ft.

It is still going down, by 0.08 ft over the past 24 hours. Without real rain upstream, that is unlikely to change quickly.

Fall is often low-water season on rivers, and it usually takes a few days of steady rain to change that.

Compared with 9 years of daily readings for this time of year. How to read levels

Key numbers

Median for this date
11.56 ft1.61 ft below the median for this date
Normal for this date
10.05 ft – 22.86 ft8 years in 10 fall in this range (9 years of records)
Same day last year
10.02 ft−0.07 ft
Lowest and highest in 30 days
9.81 ft – 10.62 ft
Lowest and highest in 12 months
7.43 ft – 12.48 ft
Highest on record
44.90 ftJune 23, 2024

Paddling and fishing conditions

At low levels, plan for shorter paddling trips and expect to walk your boat through a few shoals.

For reference, flood stage is 32.00 ft.

What happens at each level

48.00 ft
The levees on the South Dakota side are overtopped.
45.50 ft
More significant levee overtopping occurs in the Iowa Riverside Community with numerous homes and buildings flooded.
43.00 ft
The lower levees in the Iowa Riverside community are in danger of being overtopped if not sandbagged. This may result in flooding of several homes on either side of Dacotan Ave.
38.00 ft
Most of the storm drains are submerged.
37.00 ft
Several structures south of River Dr on the SD will flood if a levee failure occurs.
35.00 ft
Some lower portions south of River Dr on the SD may be at risk of flooding with a levee failure.
32.00 ft
Agricultural land north of the leveed area begins to flood.
9.95 ft
Right now

Impact statements from the U.S. National Weather Service.

Highest crests on record

Chance of at least minor flooding in October to December: < 5 %.

RankLevelDate
144.90 ftJune 23, 2024
237.70 ftJune 20, 2014
337.46 ftMarch 17, 2019
431.57 ftJune 25, 2018
521.89 ftApril 2, 2020
619.04 ftMay 4, 2016
718.57 ftApril 15, 2023
817.73 ftMay 26, 2017
915.09 ftJuly 10, 2015
1014.94 ftJune 2, 2022

Weather at the gauge

The forecast is not available right now.

Sunrise 07:45 AM Sunset 06:37 PM Daylight 10 hr, 52 min First quarter 67%

Map

Other gauges on the Big Sioux River

Gauge Level Compared with normal 24 hours Distance
Big Sioux River near CastlewoodRiver gauge, Big Sioux River 4.77 ft Below flood stage +0.03 ft 155 mi
Big Sioux River near BruceRiver gauge, Big Sioux River 3.12 ft Below flood stage −0.03 ft 136 mi
Big Sioux River near BrookingsRiver gauge, Big Sioux River 2.29 ft Below flood stage ±0 115 mi
Big Sioux River near Dell RapidsRiver gauge, Big Sioux River 3.23 ft Below flood stage −0.01 ft 88 mi
Big Sioux River below Diversion at Sioux FallsRiver gauge, Big Sioux River 3.13 ft Below flood stage ±0 74 mi
Big Sioux River at Sioux FallsRiver gauge, Big Sioux River 1.48 ft Below flood stage −0.01 ft 69 mi
Big Sioux River at North Cliff Ave at Sioux FallsRiver gauge, Big Sioux River 5.04 ft Below flood stage −0.04 ft 73 mi
Big Sioux River near HawardenRiver gauge, Big Sioux River 12.01 ft Below flood stage −0.06 ft 36 mi
Big Sioux River at AkronRiver gauge, Big Sioux River 5.60 ft Below flood stage −0.09 ft 22 mi
Big Sioux River near JeffersonRiver gauge, Big Sioux River 9.42 ft Below flood stage −0.09 ft 7 mi

Nearby gauges

Gauge Level Compared with normal 24 hours Distance
Perry Creek at 38th Street at Sioux CityRiver gauge, Perry Creek 6.56 ft Low −0.01 ft 3.6 mi
Missouri River at Sioux CityRiver gauge, Missouri River 10.50 ft Below flood stage −0.06 ft 4.3 mi
Perry Creek near HintonRiver gauge, Perry Creek 15.21 ft Below flood stage −0.01 ft 9 mi
Floyd River at JamesRiver gauge, Floyd River 8.70 ft Below flood stage −0.02 ft 9 mi
Perry Creek near MillnervilleRiver gauge, Perry Creek 0.97 ft Below flood stage ±0 13 mi
Omaha Creek at HomerRiver gauge, Omaha Creek 2.18 ft Normal −0.02 ft 14 mi
Elliott Creek at LawtonRiver gauge, Elliott Creek 72.30 ft Below flood stage −0.01 ft 15 mi
Logan Creek at WakefieldRiver gauge, Logan Creek 6.97 ft Low −0.01 ft 26 mi

Questions and answers

Is the Big Sioux River at Sioux City higher than last year?

No, it is 0.07 ft lower than on the same day last year, when the reading was 10.02 ft.

What is flood stage for the Big Sioux River at Sioux City?

The official flood stage is 32.00 ft. The level is currently 22.05 ft below it.

What is a normal level for the Big Sioux River at Sioux City in mid-October?

The median for mid-October is 11.56 ft. In 8 years out of 10 the reading falls between 10.05 ft and 22.86 ft, based on 9 years of records.

Is gage height the same as water depth?

No. Gage height is measured from a fixed reference point chosen by the agency, so a reading of 10 ft does not mean the river is 10 ft deep.

What is the water level of Big Sioux River at Sioux City today?

On Oct 20, 2026, 03:30 AM CDT, the water level was 9.95 ft. Down 0.08 ft over the last 24 hours.

Is Big Sioux River at Sioux City rising or falling?

Down 0.08 ft over the last 24 hours. Down 0.08 ft over the last 7 days.

Is the level of Big Sioux River at Sioux City normal?

Very low for mid-October. Compared with 9 years of daily readings for this time of year.

For specialists

Station codes, datum, parameters, data quality and downloads
Operator
U.S. Geological Survey
Station code
usgs:06485950 (Agency page)
Coordinates
42.52444, -96.48019 (WGS84)
Vertical datum
NAVD88
Update interval
every 15 minutes
Licence
Public domain. Data: U.S. Geological Survey (USGS), provisional data subject to revision

Published series

ParameterLast valueTime (UTC)Quality
Water level 9.95 ft 2026-10-20 08:30 Provisional

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How to cite

U.S. Geological Survey: Big Sioux River at Sioux City (usgs:06485950). Accessed October 20, 2026 via Nivelmap, https://nivelmap.com/en/united-states/iowa/big-sioux-river-at-sioux-city

How we check values

Each reading is stored as published. We hold back values that jump faster than physically plausible and show the measurement time with every value.

Readings are provisional, can be delayed or wrong and are not a flood warning. Read the disclaimer