Hydrohistorian
Grass Valley Canal near Rifle Falls
Ditch / canal gage · GRSVALCO · Division 5 · Water District 39 · Garfield County
The record
Period of record
1986-04-03 → 2026-07-06
Daily values
12,566
Latest cached reading
19.5 cfs (2026-07-06)
Trend
decreasing, -14.37 cfs/decade
Pettitt changepoint
~2008
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
Loading chart…
Where it sits
Location as DWR records it (5).
Provenance
DWR station abbreviation GRSVALCO; recorded station name “GRASS VALLEY CANAL NEAR RIFLE FALLS, CO”; operated by DWR. 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.