Water Intelligence Brief · Archive
September 21, 2026
Arkansas River Basin | September 21, 2026
Arkansas River flows in Otero County are at critically constrained late-season levels, with the Apishapa River near Fowler reading 3 cfs and rising, while the Arkansas mainstem at La Junta and Rocky Ford are currently reporting no recent data — limiting real-time delivery visibility for Fort Lyon and Catlin canal users this week. Upper Arkansas SNOTEL stations have returned to their normal end-of-season baseline at 0.0" SWE, confirming that snowmelt contributions to Pueblo Reservoir have ended and inflows are tapering toward base flow conditions. Reservoir storage data and 7-day forecast details are available in the full brief.
Both upper Arkansas headwater SNOTEL stations are reporting end-of-season conditions as of September 20:
No percent-of-median figures are shown for either station, which reflects normal seasonal conditions for this date — the historical median SWE at these locations is also 0.0" in late September. These stations are not below normal today; the snowpack signal has simply concluded for the 2026 season.
The critical 2026 context is timing: both stations melted out 4–6 weeks ahead of the historical median meltout date, driven by an anomalous March heat wave. That early meltout compressed the window for Pueblo Reservoir filling and reduced Fry-Ark import volumes to an estimated 10% of the 20-year average. That upstream constraint now defines the remainder of the irrigation season.
The Apishapa River's 3 cfs reading — while rising — reflects minimal tributary contribution to the lower Arkansas system. The absence of current data at both La Junta and Rocky Ford is a meaningful operational gap: irrigators and canal operators cannot assess mainstem delivery conditions or estimate Fort Lyon Canal diversion rates this week from gauge data alone. When both gauges are reporting, the difference between Rocky Ford and La Junta readings provides a useful proxy for active Fort Lyon Canal diversions — that comparison is unavailable until data resumes. Users should contact Fort Lyon Canal Company, Catlin Canal Company, and Holbrook Irrigation District directly for current delivery status.
Subscribe for the full brief including reservoir storage, weather forecasts, depletion analysis, and detailed operational recommendations.
Data Sources: SNOTEL data through September 20, 2026; USGS streamflow data through September 21, 2026
Data Current As Of: September 21, 2026
Important Disclaimers: This brief provides automated analysis for informational purposes only. Specific numerical claims have not been independently verified. Consult official sources including your local water district, U.S. Bureau of Reclamation Eastern Colorado Area Office (Loveland, CO — administers Fryingpan-Arkansas Project and Pueblo Reservoir), Southeastern Colorado Water Conservancy District (SECWCD), and Colorado Division of Water Resources, Water Division 2 (Pueblo office) for regulatory decisions and water rights administration.
Data & Disclaimers
Sources: NRCS SNOTEL network · USGS National Water Information System · National Weather Service
This brief provides automated analysis for informational purposes only. Consult official sources including your local water district and state Division of Water Rights for regulatory decisions. This document does not constitute legal, regulatory, or engineering advice.
Other Issues
Stay Updated
Free seasonal updates on water conditions across the Mountain West.
Free · Delivered when reports publish