Hydrohistorian
← Basin trends · All gages in this district
Arkansas River below John Martin Reservoir
Reservoir gage · ARKJMRCO · USGS 07130500 · Division 2 · Water District 67 · Bent 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.
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.
The water itself
USGS keeps a sensor here. Latest readings, with the last 30 days of daily means beside each. Provisional: not yet reviewed by USGS, and revised when it is.
Fetched 2026-10-14 03:21 UTC from USGS NWIS (site 07130500). The USGS page has the full sensor record; every Colorado sensor site is listed on one page.
Annual flow & trend
Chart: annual mean flow at Arkansas River below John Martin Reservoir, water years 1938 to 2026. The measured record is no trend at 0.7 cubic feet per second per decade. The underlying yearly values are available as a CSV download linked at the top of this page.
Where it sits
Location as DWR records it (5.0).
Provenance
DWR station abbreviation ARKJMRCO; recorded station name “ARKANSAS RIVER BELOW JOHN MARTIN RESERVOIR, 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.