USGS Streamgage 11161000
San Lorenzo River A Santa Cruz, CA
San Lorenzo River A Santa Cruz, CA is USGS streamgage 11161000 in California, monitoring river discharge in hydrologic subbasin 18060015. It drains a watershed of about 115 square miles. Discharge records at this site go back to 1952. Typical flow runs near 13.6 cfs in July and 78.3 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 115 sq mi
- Gauge elevation
- 9 ft
- Subbasin (HUC-8)
- 18060015
- Coordinates
- 36.99078, -122.03191
- USGS site number
- 11161000
- Records begin
- 1952-10-01 (74 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 74 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 | 16.1 | 89.5 | 899.1 | |
| February | 23.4 | 134.2 | 1,082.2 | |
| March | 29.1 | 133.1 | 695.7 | |
| April | 21.3 | 78.3 | 326.6 | |
| May | 13.3 | 46.8 | 144.7 | |
| June | 7.2 | 25.5 | 71.6 | |
| July | 3 | 13.6 | 42.4 | |
| August | 1.5 | 9.2 | 28.3 | |
| September | 1.1 | 8.1 | 21.8 | |
| October | 2.3 | 10.8 | 27 | |
| November | 6 | 17 | 56.5 | |
| December | 13.1 | 37.2 | 412.4 |
All values in cubic feet per second (cfs).
Common questions
- When does San Lorenzo River A Santa Cruz, CA normally run highest?
- February, on the long-term record. The median daily flow that month is about 134.2 cfs, against 8.1 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 San Lorenzo River A Santa Cruz, CA?
- It depends on the month. In January, half of days historically fall near 89.5 cfs, with the middle 80% of days between 16.1 and 899.1 cfs. The month-by-month table on this page gives the full range.
- How long has San Lorenzo River A Santa Cruz, CA been measured?
- Discharge records at USGS site 11161000 begin in 1952, about 74 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 San Lorenzo River A Santa Cruz, CA?
- The gauge sits at 36.99078, -122.03191, in California, in hydrologic subbasin 18060015, at an elevation of about 9 feet, draining roughly 115 square miles.
- Can I use San Lorenzo River A Santa Cruz, 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.