USGS Streamgage 09404120
Colorado River above National Canyon near Supai
Colorado River above National Canyon near Supai is USGS streamgage 09404120 in Arizona, monitoring river discharge in hydrologic subbasin 15010002. It drains a watershed of about 147,931 square miles. Discharge records at this site go back to 1983. Typical flow runs near 14,008.4 cfs in July and 11,372.3 cfs in April, with the higher of the two arriving in July.
Gauge details
- State
- Arizona
- Drainage area
- 147,931 sq mi
- Gauge elevation
- 1,760 ft
- Subbasin (HUC-8)
- 15010002
- Coordinates
- 36.25972, -112.89077
- USGS site number
- 09404120
- Records begin
- 1983-07-31 (43 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 10 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 | — | 13,516.1 | — | |
| February | — | 12,064.5 | — | |
| March | — | 11,537.1 | — | |
| April | — | 11,372.3 | — | |
| May | — | 11,105.2 | — | |
| June | — | 13,182 | — | |
| July | — | 14,008.4 | — | |
| August | — | 15,958.1 | — | |
| September | — | 14,426.7 | — | |
| October | — | 10,092.3 | — | |
| November | — | 10,812.3 | — | |
| December | — | 11,458.4 | — |
All values in cubic feet per second (cfs).
Common questions
- When does Colorado River above National Canyon near Supai normally run highest?
- August, on the long-term record. The median daily flow that month is about 15,958.1 cfs, against 10,092.3 cfs in October, the lowest month. These are historical normals for the date, not a forecast and not today's reading.
- How long has Colorado River above National Canyon near Supai been measured?
- Discharge records at USGS site 09404120 begin in 1983, about 43 years. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Colorado River above National Canyon near Supai?
- The gauge sits at 36.25972, -112.89077, in Arizona, in hydrologic subbasin 15010002, at an elevation of about 1,760 feet, draining roughly 147,931 square miles.
- Can I use Colorado River above National Canyon near Supai 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.