Hydrohistorian
Adams Tunnel at East Portal-Computed Flow
Transbasin diversion gage · ADANETCO · Division 1 · Water District 4 · Larimer County
What this gage meters
This is not a natural stream record. The Alva B. Adams Tunnel moves water from Colorado River headwaters at Grand Lake (Div 5) into Big Thompson River at Estes Park (Div 1), operated by Northern Water / USBR (Colorado-Big Thompson) — 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
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
Where it sits
Location as DWR records it (3.0).
Provenance
DWR station abbreviation ADANETCO; recorded station name “ADAMS TUNNEL AT EAST PORTAL-COMPUTED FLOW”; 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.