USGS Streamgage 11290000
Tuolumne River A Modesto, CA
Tuolumne River A Modesto, CA is USGS streamgage 11290000 in California, monitoring river discharge in hydrologic subbasin 18040009. It drains a watershed of about 1,884 square miles. Discharge records at this site go back to 1895. Typical flow runs near 273.4 cfs in July and 729 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 1,884 sq mi
- Gauge elevation
- 3 ft
- Subbasin (HUC-8)
- 18040009
- Coordinates
- 37.62715, -120.98438
- USGS site number
- 11290000
- Records begin
- 1895-01-01 (131 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 86 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 | 204.2 | 818.1 | 4,499.7 | |
| February | 214.3 | 1,028.1 | 5,063.8 | |
| March | 219 | 845.8 | 6,136.1 | |
| April | 238.6 | 729 | 6,708.3 | |
| May | 193.9 | 670.5 | 6,201.9 | |
| June | 117.7 | 312.8 | 5,292.3 | |
| July | 111.9 | 273.4 | 1,736.9 | |
| August | 118.9 | 266.2 | 875.3 | |
| September | 120 | 272.7 | 1,012 | |
| October | 169.9 | 530.7 | 1,456.4 | |
| November | 196.1 | 498.1 | 1,695 | |
| December | 197.2 | 733.9 | 2,661.6 |
All values in cubic feet per second (cfs).
Common questions
- When does Tuolumne River A Modesto, CA normally run highest?
- February, on the long-term record. The median daily flow that month is about 1,028.1 cfs, against 266.2 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 Tuolumne River A Modesto, CA?
- It depends on the month. In January, half of days historically fall near 818.1 cfs, with the middle 80% of days between 204.2 and 4,499.7 cfs. The month-by-month table on this page gives the full range.
- How long has Tuolumne River A Modesto, CA been measured?
- Discharge records at USGS site 11290000 begin in 1895, about 131 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 Tuolumne River A Modesto, CA?
- The gauge sits at 37.62715, -120.98438, in California, in hydrologic subbasin 18040009, at an elevation of about 3 feet, draining roughly 1,884 square miles.
- Can I use Tuolumne River A Modesto, 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
- Tuolumne River A Grand Cyn of Tuolumne Ab Hetch Hetchy
- Tuolumne River near Hetch Hetchy, CA
- Tuolumne River Ab Early Intake near Mather, CA
- Tuolumne River below Early Intake near Mather, CA
- Cherry C below Valley Dam near Hetch Hetchy, CA
- Eleanor C near Hetch Hetchy, CA
- Cherry C near Early Intake, CA
- Cherry C below Dion River Holm Ph near Mather, CA