Rivermatics

USGS Streamgage 12105900

Green River below Howard A Hanson Dam, WA

Green River below Howard A Hanson Dam, WA is USGS streamgage 12105900 in Washington, monitoring river discharge in hydrologic subbasin 17110013. It sits on the Green River, alongside 7 other gauges Rivermatics tracks on the same river. It drains a watershed of about 221 square miles. Discharge records at this site go back to 1960. Typical flow runs near 340.7 cfs in July and 1,152.7 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
Washington
Drainage area
221 sq mi
Gauge elevation
1,032 ft
Subbasin (HUC-8)
17110013
Coordinates
47.28371, -121.79788
USGS site number
12105900
Records begin
1960-10-01 (66 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Green River below Howard A Hanson Dam, WA. 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
272 282 294
267 283 305
267 297 370
266 296 370
263 298 383
261 299 395
258 300 398
258 303 406
257 306 415
256 307 417
256 310 424
256 320 465
253 321 487
255 338 545

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 66 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 485.8 1,073 3,704.8
February 474.3 988 3,063.8
March 456.9 917.6 2,128.1
April 561.3 1,152.7 2,281
May 421.8 1,112.5 2,339.4
June 279.6 624.8 1,538.5
July 234.2 340.7 712.3
August 216.7 256.9 349
September 220.6 299.7 514
October 225.5 452.3 1,184
November 354.8 904.5 2,795
December 442.1 992 3,211.6

All values in cubic feet per second (cfs).

Common questions

When does Green River below Howard A Hanson Dam, WA normally run highest?
April, on the long-term record. The median daily flow that month is about 1,152.7 cfs, against 256.9 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 Green River below Howard A Hanson Dam, WA?
It depends on the month. In January, half of days historically fall near 1,073 cfs, with the middle 80% of days between 485.8 and 3,704.8 cfs. The month-by-month table on this page gives the full range.
How long has Green River below Howard A Hanson Dam, WA been measured?
Discharge records at USGS site 12105900 begin in 1960, about 66 years, covering roughly 9,200 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Green River below Howard A Hanson Dam, WA?
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 Green River below Howard A Hanson Dam, WA?
The gauge sits at 47.28371, -121.79788, in Washington, in hydrologic subbasin 17110013, at an elevation of about 1,032 feet, draining roughly 221 square miles.
Can I use Green River below Howard A Hanson Dam, WA 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 Green River

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

Other gauges in this subbasin