Rivermatics

USGS Streamgage 11074000

Santa Ana River below Prado Dam, CA

Santa Ana River below Prado Dam, CA is USGS streamgage 11074000 in California, monitoring river discharge in hydrologic subbasin 18070203. It sits on the Santa Ana River, alongside 3 other gauges Rivermatics tracks on the same river. It drains a watershed of about 2,258 square miles. Discharge records at this site go back to 1938. Typical flow runs near 93 cfs in July and 190.4 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.

View live conditions & forecast →

Gauge details

State
California
Drainage area
2,258 sq mi
Gauge elevation
452 ft
Subbasin (HUC-8)
18070203
Coordinates
33.88335, -117.64533
USGS site number
11074000
Records begin
1938-03-02 (88 years)
Rivermatics forecast
14-day flow outlook

14-day flow forecast

Based on observations through for Santa Ana River below Prado Dam, CA. 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
115 122 130
109 121 133
104 118 135
99.2 116 135
95.2 114 134
93 114 136
90.8 113 139
85.5 110 134
85.8 112 146
86.2 115 159
86.6 117 158
85.8 116 156
81.9 111 145
79.1 108 140

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 86 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 67.4 221.8 563
February 75.9 223.3 871.9
March 70.9 237.6 834.6
April 60.7 190.4 561
May 48.2 142.6 388.4
June 40.9 119.2 318.3
July 27.4 93 249.5
August 22.9 79.1 202.7
September 25.9 85.2 191.9
October 33.1 96.8 214.7
November 46.7 127.4 271.9
December 58.6 183.2 451

All values in cubic feet per second (cfs).

Common questions

When does Santa Ana River below Prado Dam, CA normally run highest?
March, on the long-term record. The median daily flow that month is about 237.6 cfs, against 79.1 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 Santa Ana River below Prado Dam, CA?
It depends on the month. In January, half of days historically fall near 221.8 cfs, with the middle 80% of days between 67.4 and 563 cfs. The month-by-month table on this page gives the full range.
How long has Santa Ana River below Prado Dam, CA been measured?
Discharge records at USGS site 11074000 begin in 1938, about 88 years, covering roughly 9,130 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
Is there a flow forecast for Santa Ana River below Prado Dam, CA?
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 Santa Ana River below Prado Dam, CA?
The gauge sits at 33.88335, -117.64533, in California, in hydrologic subbasin 18070203, at an elevation of about 452 feet, draining roughly 2,258 square miles.
Can I use Santa Ana River below Prado Dam, CA 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 Santa Ana River

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

Other gauges in this subbasin