Big Sioux River near Watertown water level

Name: Big Sioux River near Watertown water level (U.S. Geological Survey)
Creator: U.S. Geological Survey
License: https://www.usgs.gov/information-policies-and-instructions/copyrights-and-credits

River gauge, Big Sioux River, South Dakota, United States

Directions

Very low for mid-October

Water level

3.81ft Steady over the last 24 hours

Measured Oct 20, 2026, 09:00 PM CDT (27 min ago)

Flow: 3.8 cfs

History

7 days 30 days 1 year Years compared

20252026

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

What this means

Low water at Big Sioux River near Watertown: the gauge reads 3.81 ft, far below normal for mid-October.

The median for mid-October is 4.18 ft, based on 9 years of readings, so the river stage is 0.37 ft below typical. It is 6.19 ft below the flood stage of 10.00 ft. On the same day last year the reading was 4.80 ft, a difference of −0.99 ft.

It has barely moved over the past 24 hours. Without real rain upstream, that is unlikely to change quickly. The 30-day range is 3.78 ft – 3.98 ft.

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: 4.18 ft0.37 ft below the median for this date
Normal for this date: 3.91 ft – 5.95 ft8 years in 10 fall in this range (9 years of records)
Same day last year: 4.80 ft−0.99 ft
Lowest and highest in 30 days: 3.78 ft – 3.98 ft
Lowest and highest in 12 months: 3.81 ft – 9.63 ft
Highest on record: 12.33 ftApril 7, 2001

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 10.00 ft.

What happens at each level

20.00 ft: The bridge at the gaging location is overtopped
19.00 ft: The bridge 1 mile south of the gage is overtopped
16.00 ft: The water reaches the bottom of the bridge at the gage and the bridge 1 mile south of the gage
13.00 ft: Flooding begins to affect the city of watertown and the sidewalk on the highway 81 bridge is overtopped
12.50 ft: County roads begin to flood
11.50 ft: Significant amounts of pasture and crop land are flooded
9.00 ft: The lowest banks are overtopped and minimal areas of pasture land will be flooded
3.81 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 %.

Rank	Level	Date
1	12.33 ft	April 7, 2001
2	12.09 ft	April 5, 1997
3	11.85 ft	April 13, 2023
4	11.21 ft	March 28, 2019
5	11.07 ft	March 30, 1978
6	10.67 ft	March 14, 1996
7	10.66 ft	March 15, 2010
8	10.61 ft	August 6, 2025
9	10.30 ft	March 23, 2011
10	10.11 ft	May 31, 2022

Weather at the gauge

No rain in the last 3 days.

20 Tue 69° 41° – Wind 17 mph

21 Wed 68° 43° – Wind 9 mph

22 Thu 76° 46° – Wind 15 mph

23 Fri 74° 59° 0.04 in, 26% Wind 26 mph

24 Sat 68° 48° 0.01 in Wind 25 mph

25 Sun 47° 39° 0.01 in Wind 12 mph

26 Mon 42° 32° 0.06 in Wind 13 mph

Forecast: Open-Meteo

Sunrise 07:53 AM Sunset 06:35 PM Daylight 10 hr, 42 min Waxing gibbous 73%

Map

Other gauges on the Big Sioux River

Gauge	Level	Compared with normal	24 hours	Distance
Big Sioux River near FlorenceRiver gauge, Big Sioux River	3.04 ft	Normal	−0.02 ft	12 mi
Big Sioux River at Lake Kampeska near WatertownRiver gauge, Big Sioux River	18.54 ft	Below flood stage	±0	4.0 mi
Big Sioux River at WatertownRiver gauge, Big Sioux River	3.15 ft	Below flood stage	+0.01 ft	4.5 mi
Big Sioux River at Broadway at WatertownRiver gauge, Big Sioux River	5.03 ft	Below flood stage	−0.04 ft	8 mi
Big Sioux River below WatertownRiver gauge, Big Sioux River	4.46 ft	Below flood stage	−0.01 ft	12 mi
Big Sioux River near CastlewoodRiver gauge, Big Sioux River	4.81 ft	Below flood stage	+0.03 ft	20 mi
Big Sioux River near BruceRiver gauge, Big Sioux River	3.11 ft	Below flood stage	−0.02 ft	40 mi
Big Sioux River near BrookingsRiver gauge, Big Sioux River	2.26 ft	Below flood stage	−0.04 ft	61 mi
Big Sioux River near Dell RapidsRiver gauge, Big Sioux River	3.23 ft	Below flood stage	−0.01 ft	87 mi
Big Sioux River below Diversion at Sioux FallsRiver gauge, Big Sioux River	3.11 ft	Below flood stage	−0.02 ft	101 mi
Big Sioux River at Sioux FallsRiver gauge, Big Sioux River	1.49 ft	Below flood stage	+0.01 ft	106 mi
Big Sioux River at North Cliff Ave at Sioux FallsRiver gauge, Big Sioux River	5.07 ft	Below flood stage	+0.01 ft	102 mi

Nearby gauges

Gauge	Level	Compared with normal	24 hours	Distance
Mud Creek near RauvilleRiver gauge, Mud Creek	7.63 ft	Below flood stage	−0.01 ft	2.9 mi
South Branch Tributary Mud Creek near RauvilleRiver gauge, South Branch Tributary Mud Creek	0.21 ft	Below flood stage	−0.06 ft	4.6 mi
Lake Kampeska at Water Plant at WatertownLake, Lake Kampeska	17.42 ft	Normal	±0	6 mi
Willow Creek near WatertownRiver gauge, Willow Creek	5.64 ft	Below flood stage	−0.07 ft	8 mi

Questions and answers

Is the Big Sioux River near Watertown higher than last year?

No, it is 0.99 ft lower than on the same day last year, when the reading was 4.80 ft.

What is flood stage for the Big Sioux River near Watertown?

The official flood stage is 10.00 ft. The level is currently 6.19 ft below it.

What is a normal level for the Big Sioux River near Watertown in mid-October?

The median for mid-October is 4.18 ft. In 8 years out of 10 the reading falls between 3.91 ft and 5.95 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 near Watertown today?

On Oct 20, 2026, 09:00 PM CDT, the water level was 3.81 ft. Steady over the last 24 hours.

Is Big Sioux River near Watertown rising or falling?

Steady over the last 24 hours. Steady over the last 7 days.

Is the level of Big Sioux River near Watertown 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:06479438 (Agency page)
Coordinates: 45.00611, -97.16472 (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

Parameter	Last value	Time (UTC)	Quality
Water level	3.81 ft	2026-10-21 02:00	Provisional
Flow	3.8 cfs	2026-10-21 02:00	Provisional

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How to cite

U.S. Geological Survey: Big Sioux River near Watertown (usgs:06479438). Accessed October 21, 2026 via Nivelmap, https://nivelmap.com/en/united-states/south-dakota/big-sioux-river-near-watertown

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