USGS Streamgage 11137900
Huasna River near Arroyo Grande, CA
Huasna River near Arroyo Grande, CA is USGS streamgage 11137900 in California, monitoring river discharge in hydrologic subbasin 18060007. It drains a watershed of about 103 square miles. Discharge records at this site go back to 1959. Typical flow runs near 0.4 cfs in July and 2.6 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 103 sq mi
- Gauge elevation
- 635 ft
- Subbasin (HUC-8)
- 18060007
- Coordinates
- 35.07774, -120.37179
- USGS site number
- 11137900
- Records begin
- 1959-06-01 (67 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 67 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 | 0.8 | 72.9 | |
| February | 0.1 | 1.5 | 191.2 | |
| March | 0.1 | 3.5 | 179.2 | |
| April | 0 | 2.6 | 68 | |
| May | 0 | 1.4 | 14.7 | |
| June | 0 | 0.8 | 3.6 | |
| July | 0 | 0.4 | 2.2 | |
| August | 0 | 0.2 | 1.4 | |
| September | 0 | 0.2 | 1.2 | |
| October | 0 | 0.2 | 1.1 | |
| November | 0 | 0.3 | 1.2 | |
| December | 0 | 0.5 | 6.6 |
All values in cubic feet per second (cfs).
Common questions
- When does Huasna River near Arroyo Grande, CA normally run highest?
- March, on the long-term record. The median daily flow that month is about 3.5 cfs, against 0.2 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 Huasna River near Arroyo Grande, CA?
- It depends on the month. In January, half of days historically fall near 0.8 cfs, with the middle 80% of days between 0 and 72.9 cfs. The month-by-month table on this page gives the full range.
- How long has Huasna River near Arroyo Grande, CA been measured?
- Discharge records at USGS site 11137900 begin in 1959, about 67 years, covering roughly 8,341 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Huasna River near Arroyo Grande, CA?
- The gauge sits at 35.07774, -120.37179, in California, in hydrologic subbasin 18060007, at an elevation of about 635 feet, draining roughly 103 square miles.
- Can I use Huasna River near Arroyo Grande, 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.