USGS Streamgage 11101250
Rio Hondo Ab Whittier Narrows Dam, CA
Rio Hondo Ab Whittier Narrows Dam, CA is USGS streamgage 11101250 in California, monitoring river discharge in hydrologic subbasin 18070105. It drains a watershed of about 91 square miles. Discharge records at this site go back to 1956. Typical flow runs near 1.6 cfs in July and 1.8 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 91 sq mi
- Gauge elevation
- 220 ft
- Subbasin (HUC-8)
- 18070105
- Coordinates
- 34.05834, -118.07173
- USGS site number
- 11101250
- Records begin
- 1956-03-01 (70 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 71 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 | 0.3 | 1.6 | 182.9 | |
| February | 0.4 | 2.1 | 427.8 | |
| March | 0.4 | 2.2 | 245.5 | |
| April | 0.4 | 1.8 | 151.2 | |
| May | 0.3 | 1.3 | 107.1 | |
| June | 0.4 | 1.5 | 120.9 | |
| July | 0.4 | 1.6 | 38.7 | |
| August | 0.3 | 1.5 | 12.2 | |
| September | 0.4 | 1.5 | 20.1 | |
| October | 0.3 | 1.4 | 25.4 | |
| November | 0.3 | 1.2 | 92 | |
| December | 0.3 | 1.4 | 118.7 |
All values in cubic feet per second (cfs).
Common questions
- When does Rio Hondo Ab Whittier Narrows Dam, CA normally run highest?
- March, on the long-term record. The median daily flow that month is about 2.2 cfs, against 1.2 cfs in November, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Rio Hondo Ab Whittier Narrows Dam, CA?
- It depends on the month. In January, half of days historically fall near 1.6 cfs, with the middle 80% of days between 0.3 and 182.9 cfs. The month-by-month table on this page gives the full range.
- How long has Rio Hondo Ab Whittier Narrows Dam, CA been measured?
- Discharge records at USGS site 11101250 begin in 1956, about 70 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 Rio Hondo Ab Whittier Narrows Dam, CA?
- The gauge sits at 34.05834, -118.07173, in California, in hydrologic subbasin 18070105, at an elevation of about 220 feet, draining roughly 91 square miles.
- Can I use Rio Hondo Ab Whittier Narrows Dam, 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.