Rivermatics

USGS Streamgage 12182500

Cascade River at Marblemount, WA

Cascade River at Marblemount, WA is USGS streamgage 12182500 in Washington, monitoring river discharge in hydrologic subbasin 17110005. It drains a watershed of about 172 square miles. Discharge records at this site go back to 1815. Typical flow runs near 1,380.5 cfs in July and 755.5 cfs in April, with the higher of the two arriving in July. 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
Washington
Drainage area
172 sq mi
Gauge elevation
331 ft
Subbasin (HUC-8)
17110005
Coordinates
48.52623, -121.4154
USGS site number
12182500
Records begin
1815-01-01 (211 years)
Rivermatics forecast
14-day flow outlook + water temperature

14-day flow forecast

Based on observations through for Cascade River at Marblemount, 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
222 244 265
212 239 268
237 287 384
226 281 371
214 262 329
198 242 294
189 232 283
179 223 276
176 220 276
171 216 276
161 208 264
161 208 266
155 204 264
146 195 253

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 20 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 347.1 666.9 1,800.6
February 291.4 539.2 1,637.9
March 282.4 537.3 1,655.8
April 424 755.5 1,532.3
May 900.5 1,598.8 3,273.2
June 1,073.3 1,989.7 3,151.7
July 666.3 1,380.5 2,618.4
August 412.6 636.3 1,258
September 275.7 421.1 980.4
October 229 510.6 1,906.3
November 403 904.1 3,018
December 361.8 660.9 1,762.9

All values in cubic feet per second (cfs).

Common questions

When does Cascade River at Marblemount, WA normally run highest?
June, on the long-term record. The median daily flow that month is about 1,989.7 cfs, against 421.1 cfs in September, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
What is a normal flow for Cascade River at Marblemount, WA?
It depends on the month. In January, half of days historically fall near 666.9 cfs, with the middle 80% of days between 347.1 and 1,800.6 cfs. The month-by-month table on this page gives the full range.
How long has Cascade River at Marblemount, WA been measured?
Discharge records at USGS site 12182500 begin in 1815, about 211 years, covering roughly 7,369 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Cascade River at Marblemount, 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. 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 Cascade River at Marblemount, WA?
The gauge sits at 48.52623, -121.4154, in Washington, in hydrologic subbasin 17110005, at an elevation of about 331 feet, draining roughly 172 square miles.
Can I use Cascade River at Marblemount, 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.

Other gauges in this subbasin