USGS Streamgage 09426000
Bill Williams River below Alamo Dam, AZ
Bill Williams River below Alamo Dam, AZ is USGS streamgage 09426000 in Arizona, monitoring river discharge in hydrologic subbasin 15030204. It drains a watershed of about 4,633 square miles. Discharge records at this site go back to 1891. Typical flow runs near 24.9 cfs in July and 25.2 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- Arizona
- Drainage area
- 4,633 sq mi
- Gauge elevation
- 954 ft
- Subbasin (HUC-8)
- 15030204
- Coordinates
- 34.23108, -113.60993
- USGS site number
- 09426000
- Records begin
- 1891-02-21 (135 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 57 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 | 6.3 | 19.9 | 67.6 | |
| February | 8.2 | 23.8 | 444.6 | |
| March | 9.5 | 26.4 | 1,533.6 | |
| April | 6.2 | 25.2 | 380.8 | |
| May | 1.2 | 25 | 168.1 | |
| June | 0.6 | 25.1 | 117.8 | |
| July | 1 | 24.9 | 119.8 | |
| August | 7 | 26.4 | 178 | |
| September | 6.4 | 26.1 | 226.3 | |
| October | 6.3 | 20.5 | 123.7 | |
| November | 5.7 | 18.1 | 68.1 | |
| December | 6.1 | 17.9 | 66.4 |
All values in cubic feet per second (cfs).
Common questions
- When does Bill Williams River below Alamo Dam, AZ normally run highest?
- March, on the long-term record. The median daily flow that month is about 26.4 cfs, against 17.9 cfs in December, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- What is a normal flow for Bill Williams River below Alamo Dam, AZ?
- It depends on the month. In January, half of days historically fall near 19.9 cfs, with the middle 80% of days between 6.3 and 67.6 cfs. The month-by-month table on this page gives the full range.
- How long has Bill Williams River below Alamo Dam, AZ been measured?
- Discharge records at USGS site 09426000 begin in 1891, about 135 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 Bill Williams River below Alamo Dam, AZ?
- The gauge sits at 34.23108, -113.60993, in Arizona, in hydrologic subbasin 15030204, at an elevation of about 954 feet, draining roughly 4,633 square miles.
- Can I use Bill Williams River below Alamo Dam, AZ 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.