USGS Streamgage 09470500
San Pedro River at Palominas, AZ
San Pedro River at Palominas, AZ is USGS streamgage 09470500 in Arizona, monitoring river discharge in hydrologic subbasin 15050202. It drains a watershed of about 737 square miles. Discharge records at this site go back to 1926. Typical flow runs near 8.8 cfs in July and 0.4 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Arizona
- Drainage area
- 737 sq mi
- Gauge elevation
- 4,204 ft
- Subbasin (HUC-8)
- 15050202
- Coordinates
- 31.38013, -110.11121
- USGS site number
- 09470500
- Records begin
- 1926-09-28 (100 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 76 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 | 0 | 2 | 12.3 | |
| February | 0 | 2.1 | 16.3 | |
| March | 0 | 1.6 | 9.3 | |
| April | 0 | 0.4 | 4 | |
| May | 0 | 0.1 | 1.1 | |
| June | 0 | 0 | 2.3 | |
| July | 0 | 8.8 | 235.7 | |
| August | 0 | 18.6 | 370.8 | |
| September | 0 | 1.4 | 56.7 | |
| October | 0 | 0.1 | 8.4 | |
| November | 0 | 0.3 | 6.2 | |
| December | 0 | 1.5 | 8.3 |
All values in cubic feet per second (cfs).
Common questions
- When does San Pedro River at Palominas, AZ normally run highest?
- August, on the long-term record. The median daily flow that month is about 18.6 cfs, against 0 cfs in June, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for San Pedro River at Palominas, AZ?
- It depends on the month. In January, half of days historically fall near 2 cfs, with the middle 80% of days between 0 and 12.3 cfs. The month-by-month table on this page gives the full range.
- How long has San Pedro River at Palominas, AZ been measured?
- Discharge records at USGS site 09470500 begin in 1926, about 100 years, covering roughly 9,125 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is San Pedro River at Palominas, AZ?
- The gauge sits at 31.38013, -110.11121, in Arizona, in hydrologic subbasin 15050202, at an elevation of about 4,204 feet, draining roughly 737 square miles.
- Can I use San Pedro River at Palominas, AZ 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.