USGS Streamgage 11028500
Santa Maria C near Ramona, CA
Santa Maria C near Ramona, CA is USGS streamgage 11028500 in California, monitoring river discharge in hydrologic subbasin 18070304. It drains a watershed of about 58 square miles. Discharge records at this site go back to 1912. Typical flow runs near 0 cfs in July and 0.2 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 58 sq mi
- Gauge elevation
- 1,296 ft
- Subbasin (HUC-8)
- 18070304
- Coordinates
- 33.05227, -116.94558
- USGS site number
- 11028500
- Records begin
- 1912-12-01 (114 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 114 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 | 0.1 | 10 | |
| February | 0 | 0.2 | 37.3 | |
| March | 0 | 0.4 | 43.4 | |
| April | 0 | 0.2 | 20.3 | |
| May | 0 | 0 | 4.9 | |
| June | 0 | 0 | 1 | |
| July | 0 | 0 | 0.2 | |
| August | 0 | 0 | 0.1 | |
| September | 0 | 0 | 0.1 | |
| October | 0 | 0 | 0.1 | |
| November | 0 | 0 | 0.3 | |
| December | 0 | 0 | 1.3 |
All values in cubic feet per second (cfs).
Common questions
- When does Santa Maria C near Ramona, CA normally run highest?
- March, on the long-term record. The median daily flow that month is about 0.4 cfs, against 0 cfs in May, 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 Maria C near Ramona, CA?
- It depends on the month. In January, half of days historically fall near 0.1 cfs, with the middle 80% of days between 0 and 10 cfs. The month-by-month table on this page gives the full range.
- How long has Santa Maria C near Ramona, CA been measured?
- Discharge records at USGS site 11028500 begin in 1912, about 114 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 Maria C near Ramona, CA?
- The gauge sits at 33.05227, -116.94558, in California, in hydrologic subbasin 18070304, at an elevation of about 1,296 feet, draining roughly 58 square miles.
- Can I use Santa Maria C near Ramona, 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.