Streamflow
Below normalColorado River at Lees Ferry streamflow
Daily mean discharge, Colorado (Compact Point) basin, Arizona
Data through Oct 15, 2026 · source last checked Oct 17, 2026 · page revised Oct 16, 2026
Cite
- Discharge
About this data
- Source
- US Geological Survey (USGS)
- Series
- Daily mean streamflow (discharge)
- Geography
- Colorado River at Lees Ferry
- Unit
- cfs
- Calculation
- Daily mean
- Last observation
- Oct 15, 2026
- Update frequency
- Daily
Now 6,580 cfs, 15% below the 5-yr median.
Colorado River discharge at Lees Ferry stood at 6,580 cfs, 15% below the 5-year median. Flow declined 18.1% month over month from 8,030 cfs. Year over year, discharge fell 15.3% from 7,770 cfs.
| Period | Current | Prior | Change |
|---|---|---|---|
| Week over week | 6,580 cfs | 6,600 cfs | -0.3% |
| Month over month | 6,580 cfs | 8,030 cfs | -18.1% |
| Year over year | 6,580 cfs | 7,770 cfs | -15.3% |
| vs 5-yr median | 6,580 cfs | 7,760 cfs | -15.2% |
| Reading | Discharge |
|---|---|
| Lowest on record for this week | 6,880 cfs |
| Median for this week | 7,760 cfs |
| Highest on record for this week | 8,310 cfs |
Previous weeks
An earlier week
Discharge at Lees Ferry reads 6,590 cfs, down 16.3% over the past month and 17.9% year over year. The flow sits 17% below the 5-year median.
Week of Oct 7, 2026
Discharge at Lees Ferry dropped to 6,640 cfs, down 16.4% week over week. The flow is 17% below the 5-year median and down 17.2% from a year ago.
Week of Sep 30, 2026
Discharge at Lees Ferry stood at 7,940 cfs, 16% below the 5-year median. Week over week the flow dipped 1.6%, while year-over-year it declined 15.6%.
Week of Sep 23, 2026
Colorado River discharge at Lees Ferry is 8,070 cfs, 15% below the 5-yr median. Flow rose 3.1% on the week but sits 17.1% below last year's level.
About Colorado River at Lees Ferry
The Colorado River at Lees Ferry ran 6,580 cfs on Oct 15, 2026: 6,580 cubic feet of water passing the gauge every second (what cfs means), or about 13,051 acre-feet a day. That is 15% below the 5-year median of 7,760 cfs for the date, and below the lowest reading for this week of the year in the 5-year record (6,880 cfs). A month earlier it ran 8,030 cfs on Sep 15, 2026, so the river has fallen 18% since then. The water passing Lees Ferry was released from Lake Powell at Glen Canyon Dam and runs on through Grand Canyon into Lake Mead, so this line is the main supply of the lake below it.
USGS gage 09380000 sits on the Colorado River at Lees Ferry, Arizona, about 15 miles below Glen Canyon Dam and just above the head of Grand Canyon. It is the most consequential streamflow station in the West: the Colorado River Compact divides the basin at this point, and the Upper Basin's delivery obligation to the Lower Basin is measured as flow past this gage.
Because it sits below Glen Canyon Dam, what it records is almost entirely a release schedule rather than a hydrograph. Reclamation sets an annual release volume for Lake Powell and shapes it month to month, so the natural snowmelt peak that dominates every unregulated gage upstream barely appears here; the visible pattern is instead the daily and seasonal rhythm of hydropower generation. A change in the level of this line is a change in policy, usually an annual operating decision made months earlier, and it shows up downstream in Lake Mead.