USGS Streamgage 09486500
Santa Cruz River at Cortaro, AZ
Santa Cruz River at Cortaro, AZ is USGS streamgage 09486500 in Arizona, monitoring river discharge in hydrologic subbasin 15050302. It drains a watershed of about 3,503 square miles. Discharge records at this site go back to 1939. Typical flow runs near 40.5 cfs in July and 38.3 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Arizona
- Drainage area
- 3,503 sq mi
- Gauge elevation
- 2,124 ft
- Subbasin (HUC-8)
- 15050302
- Coordinates
- 32.35072, -111.09588
- USGS site number
- 09486500
- Records begin
- 1939-10-01 (87 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 87 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 | 44.9 | 80.7 | |
| February | 0 | 42 | 80.9 | |
| March | 0 | 40.2 | 71.4 | |
| April | 0 | 38.3 | 60.5 | |
| May | 0 | 36.8 | 57.6 | |
| June | 0 | 35 | 57.3 | |
| July | 0 | 40.5 | 233.9 | |
| August | 0 | 46.1 | 261.3 | |
| September | 0 | 44.2 | 96.3 | |
| October | 0 | 40.3 | 64.2 | |
| November | 0 | 42.5 | 68.3 | |
| December | 0 | 44.8 | 75.3 |
All values in cubic feet per second (cfs).
Common questions
- When does Santa Cruz River at Cortaro, AZ normally run highest?
- August, on the long-term record. The median daily flow that month is about 46.1 cfs, against 35 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 Santa Cruz River at Cortaro, AZ?
- It depends on the month. In January, half of days historically fall near 44.9 cfs, with the middle 80% of days between 0 and 80.7 cfs. The month-by-month table on this page gives the full range.
- How long has Santa Cruz River at Cortaro, AZ been measured?
- Discharge records at USGS site 09486500 begin in 1939, about 87 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 Cruz River at Cortaro, AZ?
- The gauge sits at 32.35072, -111.09588, in Arizona, in hydrologic subbasin 15050302, at an elevation of about 2,124 feet, draining roughly 3,503 square miles.
- Can I use Santa Cruz River at Cortaro, 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.