Streamflow
Below normalGunnison River below Gunnison Tunnel streamflow
Daily mean discharge, Gunnison-Colorado basin, Colorado
Data through Oct 28, 2026 · source last checked Oct 30, 2026 · page revised Oct 29, 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 28, 2026
- Update frequency
- Daily
Now 273 cfs, 19% below the 5-yr median.
The Gunnison River below Gunnison Tunnel ran at 273 cfs, 19% below the 5-year median. Flow rose 28.2% on the week and 27.6% on the month, though it remains 17.5% below year-ago levels.
| Period | Current | Prior | Change |
|---|---|---|---|
| Week over week | 273 cfs | 213 cfs | +28.2% |
| Month over month | 273 cfs | 214 cfs | +27.6% |
| Year over year | 273 cfs | 331 cfs | -17.5% |
| vs 5-yr median | 273 cfs | 338 cfs | -19.2% |
| Reading | Discharge |
|---|---|
| Lowest on record for this week | 282 cfs |
| Median for this week | 338 cfs |
| Highest on record for this week | 475 cfs |
Previous weeks
An earlier week
The gauge read 227 cfs through Oct 27, running 33% below the 5-yr median. Year over year, flow is down 30.2%. It has recovered 6.6% from a week earlier.
An earlier week
The gauge reads 227 cfs, 33% below the 5-yr median. Flow has risen 6.6% week over week. Year-over-year discharge is 26.3% lower.
Week of Oct 25, 2026
Gunnison River discharge stands at 228 cfs, 33% below the 5-year median. The gauge gained 7% on the week but has fallen 26% year over year.
An earlier week
Gunnison River below Gunnison Tunnel measured 228 cfs, up 7% on the week but down 26% year-over-year. The current flow is 32% below the 5-yr median.
About Gunnison River below Gunnison Tunnel
The Gunnison River below Gunnison Tunnel ran 273 cfs on Oct 28, 2026: 273 cubic feet of water passing the gauge every second (what cfs means), or about 541 acre-feet a day. In gallons, that is about 122,531 gallons per minute (convert cfs to gpm). That is 19% below the 5-year median of 338 cfs for the date, and below the lowest reading for this week of the year in the 5-year record (282 cfs). A month earlier it ran 214 cfs on Sep 28, 2026, so the river has risen 28% 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.