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 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.
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)
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.
| 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 9,126 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- 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.
Other gauges in this subbasin
- Santiago C A Modjeska, CA
- Santiago C A Santa Ana, CA
- Santa Ana River A Santa Ana, CA
- Sce Santa Ana River Cn Ab Pp3 near Mentone, CA
- Santa Ana River Canal Greenspot Spill near Mentone, CA
- Santa Ana River near Mentone (River Only), CA
- Santa Ana River near Mentone, CA
- Santa Ana River near Mentone Cn + Cn, CA