Rivermatics

USGS Streamgage 06480000

Big Sioux River near Brookings, SD

Big Sioux River near Brookings, SD is USGS streamgage 06480000 in South Dakota, monitoring river discharge in hydrologic subbasin 10170203. It sits on the Big Sioux River, alongside 16 other gauges Rivermatics tracks on the same river. It drains a watershed of about 3,338 square miles. Discharge records at this site go back to 1953. Typical flow runs near 162.1 cfs in July and 430.1 cfs in April, with the higher of the two arriving in April. Rivermatics issues a daily machine-learned flow outlook for this gauge, reaching 14 days ahead.

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Gauge details

State
South Dakota
Drainage area
3,338 sq mi
Gauge elevation
1,555 ft
Subbasin (HUC-8)
10170203
Coordinates
44.18028, -96.74917
USGS site number
06480000
Records begin
1953-08-01 (73 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Big Sioux River near Brookings, SD. Each day carries a median estimate and the band the model expects the flow to fall within — not a single number to plan against. Forecasts are re-issued daily; see the live screen for the current outlook.

Forecast daily mean discharge in cubic feet per second, by date
Date Low p10 Expected p50 High p90 Range
82.9 90.5 97.1
78.7 87.9 96.9
78.8 90.8 113
76.1 92 129
75.5 92.5 133
74.2 92.3 136
77.2 99.7 175
87.5 134 371
83.8 152 654
85.5 170 689
86.5 171 614
84.7 165 541
79.9 153 492
77.4 146 494

All values in cubic feet per second (cfs). Estimates only — do not use them for navigation or for any safety, rescue, or emergency decision.

Typical flow by month

Long-term daily discharge percentiles from the USGS record (up to 73 years of data), averaged within each month. These describe the historical normal range — they are not a forecast and not today's reading.

Historical monthly discharge percentiles in cubic feet per second
Month Low p10 Typical p50 High p90 Range
January 2 25.5 167.5
February 1.2 24.7 275.1
March 12.9 219.1 1,754.8
April 75.3 430.1 3,107.7
May 49.2 382.5 1,906.5
June 35.6 310.1 1,690.3
July 20 162.1 1,264.2
August 10.9 84.9 857.6
September 7 66.6 632.1
October 10.7 74.7 613.6
November 13.4 69.9 423.4
December 5.3 48.5 256

All values in cubic feet per second (cfs).

Common questions

When does Big Sioux River near Brookings, SD normally run highest?
April, on the long-term record. The median daily flow that month is about 430.1 cfs, against 24.7 cfs in February, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Big Sioux River near Brookings, SD?
It depends on the month. In January, half of days historically fall near 25.5 cfs, with the middle 80% of days between 2 and 167.5 cfs. The month-by-month table on this page gives the full range.
How long has Big Sioux River near Brookings, SD been measured?
Discharge records at USGS site 06480000 begin in 1953, about 73 years, covering roughly 9,082 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Big Sioux River near Brookings, SD?
Yes. Rivermatics trains a machine-learned model — a temporal-fusion transformer — on this basin's observed flows, weather, and snowpack, and issues a daily flow outlook reaching 14 days ahead: a median estimate inside a confidence band, not a single number to bet on. Every forecast is scored against days the model never trained on, and that track record is published on the live gauge screen. Open live conditions to see the current outlook.
Where is Big Sioux River near Brookings, SD?
The gauge sits at 44.18028, -96.74917, in South Dakota, in hydrologic subbasin 10170203, at an elevation of about 1,555 feet, draining roughly 3,338 square miles.
Can I use Big Sioux River near Brookings, SD data for flood or safety decisions?
No. Rivermatics provides estimates, not guarantees, and the readings and forecasts here may be delayed, inaccurate, or wrong. Do not use them for navigation or for any safety, rescue, or emergency decision. Check the National Weather Service and USGS directly, and use your own judgment.

Upstream and downstream on the Big Sioux River

Every gauge Rivermatics tracks on this river, ordered by drainage area — upstream first. See the Big Sioux River in full.

Other gauges in this subbasin