Streamflow
Below normalGunnison River below Gunnison Tunnel streamflow
Daily mean discharge, Gunnison-Colorado basin, Colorado
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
- Gunnison River below Gunnison Tunnel
- Unit
- cfs
- Calculation
- Daily mean
- Last observation
- Oct 15, 2026
- Update frequency
- Daily
Now 240 cfs, 31% below the 5-yr median.
Discharge was 240 cfs, 31% below the 5-year median. Flow rose 14.8% from a week ago but remains 30.6% below last year's 346 cfs.
| Period | Current | Prior | Change |
|---|---|---|---|
| Week over week | 240 cfs | 209 cfs | +14.8% |
| Month over month | 240 cfs | 255 cfs | -5.9% |
| Year over year | 240 cfs | 346 cfs | -30.6% |
| vs 5-yr median | 240 cfs | 346 cfs | -30.6% |
| Reading | Discharge |
|---|---|
| Lowest on record for this week | 308 cfs |
| Median for this week | 346 cfs |
| Highest on record for this week | 479 cfs |
Previous weeks
An earlier week
Discharge measured 208 cfs on 2026-10-14, 40% below the 5-year median. Flow fell 11.1% from the prior month and 39.9% compared to a year ago.
Week of Oct 7, 2026
Gunnison River below Gunnison Tunnel is running at 209 cfs, 42% below the 5-year median. Flow fell 17.7% over the past month and 41.9% year over year.
Week of Sep 30, 2026
The Gunnison River below Gunnison Tunnel ran at 210 cfs, down 41.8% from a year ago. Flow is 53% below the 5-year median. The gauge fell 14.6% week over week.
Week of Sep 23, 2026
Gunnison River discharge sits at 246 cfs, 45% below the 5-year median. The river is down 36.3% year over year and 7.2% on the month.
About Gunnison River below Gunnison Tunnel
The Gunnison River below Gunnison Tunnel ran 240 cfs on Oct 15, 2026: 240 cubic feet of water passing the gauge every second (what cfs means), or about 476 acre-feet a day. That is 31% below the 5-year median of 346 cfs for the date, and below the lowest reading for this week of the year in the 5-year record (308 cfs). A month earlier it ran 255 cfs on Sep 15, 2026, so the river has fallen 6% since then. Its water comes out of the Aspinall Unit, led by Blue Mesa Reservoir. Below the Black Canyon the Gunnison joins the Colorado at Grand Junction, upstream of the Colorado River near Cisco gauge.
USGS gage 09128000 sits on the Gunnison River just below the Gunnison Tunnel diversion, at the foot of the Black Canyon in western Colorado. Above it is Reclamation's Aspinall Unit, the three-reservoir chain of Blue Mesa, Morrow Point and Crystal that stores most of the upper Gunnison's runoff. Directly at this point the Gunnison Tunnel takes water out of the river and carries it under the canyon rim to the Uncompahgre Valley, so the gage reads the river after both the reservoirs and the diversion have had their say.
The year runs on release schedules: a spring peak shaped to meet a National Park Service water right in the Black Canyon, then a summer floor. Because Blue Mesa is the largest reservoir in Colorado and a key piece of Upper Basin drought-response storage, low readings here are usually a symptom of a decision to hold water back rather than of the weather in any given week.