USGS Streamgage 11151870
Arroyo Seco near Greenfield, CA
Arroyo Seco near Greenfield, CA is USGS streamgage 11151870 in California, monitoring river discharge in hydrologic subbasin 18060005. It drains a watershed of about 113 square miles. Discharge records at this site go back to 1961. Typical flow runs near 11.8 cfs in July and 142.3 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 113 sq mi
- Gauge elevation
- 778 ft
- Subbasin (HUC-8)
- 18060005
- Coordinates
- 36.23746, -121.4816
- USGS site number
- 11151870
- Records begin
- 1961-10-01 (65 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 65 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 | 17.7 | 101.1 | 1,288.4 | |
| February | 33.1 | 154.5 | 1,595.1 | |
| March | 30.1 | 196 | 1,216.7 | |
| April | 24 | 142.3 | 591 | |
| May | 11.8 | 80 | 243.8 | |
| June | 3.6 | 33.9 | 98.8 | |
| July | 0.6 | 11.8 | 50.5 | |
| August | 0.1 | 7.6 | 27.4 | |
| September | 0.6 | 5.2 | 21.4 | |
| October | 1.1 | 8.3 | 24.6 | |
| November | 5.5 | 20.3 | 167.5 | |
| December | 13 | 52.5 | 563.7 |
All values in cubic feet per second (cfs).
Common questions
- When does Arroyo Seco near Greenfield, CA normally run highest?
- March, on the long-term record. The median daily flow that month is about 196 cfs, against 5.2 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 Arroyo Seco near Greenfield, CA?
- It depends on the month. In January, half of days historically fall near 101.1 cfs, with the middle 80% of days between 17.7 and 1,288.4 cfs. The month-by-month table on this page gives the full range.
- How long has Arroyo Seco near Greenfield, CA been measured?
- Discharge records at USGS site 11151870 begin in 1961, about 65 years, covering roughly 1,486 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Arroyo Seco near Greenfield, CA?
- The gauge sits at 36.23746, -121.4816, in California, in hydrologic subbasin 18060005, at an elevation of about 778 feet, draining roughly 113 square miles.
- Can I use Arroyo Seco near Greenfield, 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
- Arroyo Seco near Soledad, CA
- Arroyo Seco below Reliz C near Soledad, CA
- Salinas River near Chualar, CA
- Salinas River near Spreckels, CA
- Salinas River near Santa Margarita, CA
- Salinas River A Paso Robles, CA
- Nacimiento River below Sapaque C near Bryson, CA
- Nacimiento River below Nacimiento Dam near Bradley, CA