Rivermatics

USGS Streamgage 14187500

South Santiam River at Waterloo, OR

South Santiam River at Waterloo, OR is USGS streamgage 14187500 in Oregon, monitoring river discharge in hydrologic subbasin 17090006. It sits on the South Santiam River, alongside 5 other gauges Rivermatics tracks on the same river. It drains a watershed of about 640 square miles. Discharge records at this site go back to 1905. Typical flow runs near 728.5 cfs in July and 3,193 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, alongside daily high and low water-temperature forecasts.

View live conditions & forecast →

Gauge details

State
Oregon
Drainage area
640 sq mi
Subbasin (HUC-8)
17090006
Coordinates
44.49846, -122.82342
USGS site number
14187500
Records begin
1905-07-01 (121 years)
Rivermatics forecast
14-day flow outlook + water temperature

14-day flow forecast

Based on observations through for South Santiam River at Waterloo, OR. 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
1,565 1,626 1,712
1,526 1,610 1,725
1,506 1,635 1,895
1,471 1,626 1,823
1,427 1,629 1,893
1,370 1,631 1,923
1,320 1,630 1,931
1,280 1,628 1,942
1,237 1,633 1,958
1,192 1,632 1,971
1,177 1,634 1,996
1,174 1,638 2,022
1,162 1,634 2,035
1,116 1,628 2,053

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 121 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 1,530.6 4,307.7 11,296.8
February 1,126.9 2,953.8 9,434.1
March 1,209.7 2,873.5 7,742.6
April 1,299.3 3,193 6,262
May 962.6 2,323.2 4,990.3
June 664.7 1,320.1 3,301
July 347.7 728.5 1,067.6
August 185.9 599.2 964.8
September 156.4 850.7 1,690.7
October 202.3 1,317.2 3,211
November 725 3,121 8,906.7
December 1,401.9 4,337.1 11,922.6

All values in cubic feet per second (cfs).

Common questions

When does South Santiam River at Waterloo, OR normally run highest?
December, on the long-term record. The median daily flow that month is about 4,337.1 cfs, against 599.2 cfs in August, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for South Santiam River at Waterloo, OR?
It depends on the month. In January, half of days historically fall near 4,307.7 cfs, with the middle 80% of days between 1,530.6 and 11,296.8 cfs. The month-by-month table on this page gives the full range.
How long has South Santiam River at Waterloo, OR been measured?
Discharge records at USGS site 14187500 begin in 1905, about 121 years, covering roughly 8,902 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for South Santiam River at Waterloo, OR?
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. A companion model forecasts each day's water-temperature high and low. 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 South Santiam River at Waterloo, OR?
The gauge sits at 44.49846, -122.82342, in Oregon, in hydrologic subbasin 17090006, draining roughly 640 square miles.
Can I use South Santiam River at Waterloo, OR 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 South Santiam River

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

Other gauges in this subbasin