USGS Streamgage 09429490
Colorado River above Imperial Dam, Az-Ca
Colorado River above Imperial Dam, Az-Ca is USGS streamgage 09429490 in California, monitoring river discharge in hydrologic subbasin 15030104. It drains a watershed of about 188,500 square miles. Discharge records at this site go back to 1973. Typical flow runs near 9,979 cfs in July and 11,036.7 cfs in April, with the higher of the two arriving in April.
Gauge details
- State
- California
- Drainage area
- 188,500 sq mi
- Subbasin (HUC-8)
- 15030104
- Coordinates
- 32.88494, -114.46811
- USGS site number
- 09429490
- Records begin
- 1973-10-16 (53 years)
Typical flow by month
Long-term daily discharge percentiles from the USGS record (up to 50 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 | 3,149.4 | 5,179.4 | 14,938.7 | |
| February | 4,503.8 | 6,956.6 | 16,006.9 | |
| March | 6,961.3 | 9,519 | 15,038.7 | |
| April | 8,851.7 | 11,036.7 | 14,540 | |
| May | 7,791.9 | 9,725.2 | 13,738.7 | |
| June | 7,875.7 | 9,583.7 | 15,153.3 | |
| July | 7,816.1 | 9,979 | 17,332.3 | |
| August | 6,554.2 | 8,679.7 | 16,032.3 | |
| September | 6,198.3 | 7,839.7 | 14,703.3 | |
| October | 5,526.5 | 7,086.5 | 13,209.7 | |
| November | 4,361.3 | 5,909 | 12,076.7 | |
| December | 3,461.9 | 5,074.5 | 14,735.5 |
All values in cubic feet per second (cfs).
Common questions
- When does Colorado River above Imperial Dam, Az-Ca normally run highest?
- April, on the long-term record. The median daily flow that month is about 11,036.7 cfs, against 5,074.5 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 Colorado River above Imperial Dam, Az-Ca?
- It depends on the month. In January, half of days historically fall near 5,179.4 cfs, with the middle 80% of days between 3,149.4 and 14,938.7 cfs. The month-by-month table on this page gives the full range.
- How long has Colorado River above Imperial Dam, Az-Ca been measured?
- Discharge records at USGS site 09429490 begin in 1973, about 53 years, covering roughly 9,125 days of published daily values. The long record is what makes the monthly percentiles on this page meaningful.
- Where is Colorado River above Imperial Dam, Az-Ca?
- The gauge sits at 32.88494, -114.46811, in California, in hydrologic subbasin 15030104, draining roughly 188,500 square miles.
- Can I use Colorado River above Imperial Dam, Az-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
- Crir Main Canal near Parker, AZ
- Gardner Lateral Spill near Parker, AZ
- Poston Wasteway near Poston, AZ
- Palo Verde Canal near Blythe, CA
- Palo Verde Drain near Parker, AZ
- Crir Lwr Main Drain below Tyson Ww, near Ehrenberg, AZ
- Colorado River below Palo Verde Dam, Az-Ca
- Pvid F-Canal Spill near Blythe, CA