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Gunnison River below Gunnison Tunnel

Transbasin diversion gage · GUNBEPCO · USGS 09128000 · Division 4 · Water District 62 · Montrose County

Live gage at DWR ↗ · USGS monitoring location ↗ · Download daily record (CSV)

Source DWR administrative record · verify at DWR station ↗ Source Independent agency measurement · verify at USGS ↗ Source Our computation, no independent reference · computed here from the screened record

Two different numbers, deliberately: Flowing now is raw 15-minute telemetry, provisional and unreviewed. Latest cached reading is the end of the verified daily record. They are never merged, and the verified series is the one the trend is computed on.

What this gage meters

This is not a natural stream record. The Gunnison Tunnel moves water from Gunnison River in the Black Canyon (Div 4, WD 62) into Uncompahgre Valley via the South Canal (Div 4, WD 68), operated by Uncompahgre Valley Water Users Assn. / USBR — so this record is a ledger of those deliveries. Trends here reflect operational and demand decisions, not the basin's hydrology, and the basin trends page marks it accordingly (⇆). All of Colorado's curated transbasin diversions are collected at /transbasin.

The record

Period of record
1910-10-01 → 2026-09-27
Daily values
42,366
Flowing now
222.0 cfs 2026-10-31 12:00, 3.3 h ago
Latest cached reading
218.0 cfs (2026-09-27)
Trend
decreasing, -79.66 cfs/decade (-7.2% of median)
Pettitt changepoint
~1952

Readings come from the weekly-refreshed cache, never fetched live — the date beside the value says exactly how fresh it is. The live gage is one click up.

Annual flow & trend

Chart: annual mean flow at Gunnison River below Gunnison Tunnel, water years 1910 to 2026. The measured record is decreasing at -79.66 cubic feet per second per decade. A Pettitt changepoint is detected around 1952. The underlying yearly values are available as a CSV download linked at the top of this page.

Loading chart…

This gage measures the Gunnison Tunnel, water carried across the Continental Divide. It is taken from Gunnison River in the Black Canyon (Div 4, WD 62) and delivered to Uncompahgre Valley via the South Canal (Div 4, WD 68) — so what this gage reads leaves one river basin for good and arrives in another.

The two ends: Gunnison Tunnel and South Canal (source, on Gunnison River)

Decrees:

The ditch’s mapped channel is drawn on the map below where the USGS has surveyed it. Every crossing →

Where it sits

Location as DWR records it (5.0).

Provenance

DWR station abbreviation GUNBEPCO; recorded station name “GUNNISON RIVER BELOW GUNNISON TUNNEL, CO”; operated by USGS. Daily flows from the DWR HydroBase snapshot plus CDSS REST updates, refreshed on the weekly cycle. Trend statistics are Mann-Kendall (Hamed-Rao corrected) with Sen's slope in native cfs, the same numbers as the basin Trends tab.