Larimer County Water Intelligence Brief

June 15, 2026 | Cache la Poudre & Big Thompson Corridors | Free-Tier Edition

Situation Summary

Both the Cache la Poudre and Big Thompson river systems entered the 2026 irrigation season with snowpack that melted out 4–6 weeks ahead of the historical median meltout date, driven by an anomalous March heat wave across the Mountain West. As of mid-June, streamflows on both rivers are falling, reflecting the transition from snowmelt-driven runoff to baseflow conditions earlier in the season than typical. Reservoir storage data for Horsetooth Reservoir and Carter Lake, along with 7-day forecast details and depletion analysis, are available in the full brief.

Snowpack Conditions

All five SNOTEL stations monitoring Larimer County's headwaters — across both the Big Thompson and Cache la Poudre watersheds — are reporting at or near zero snow water equivalent (SWE) as of June 14, 2026.

Big Thompson Headwaters (Rocky Mountain National Park corridor):

Cache la Poudre Headwaters:

The critical framing for 2026 is not current SWE totals — most stations showing 0.0" are at or near their normal seasonal condition for mid-June. The meaningful signal is meltout timing: across both watersheds, snowpack melted out approximately 4–6 weeks ahead of the historical median meltout date. That early meltout compressed the runoff season, concentrating spring peak flows earlier and shortening the window for reservoir filling and direct-flow diversions. The Joe Wright reading at 11% of median is the only station currently indicating a residual below-normal condition.

Streamflow Conditions

Both river systems are showing falling flows as of June 15, 2026, consistent with the transition from snowmelt runoff to summer baseflow conditions.

Cache la Poudre River:

Both gauges are physically within Larimer County and capture flow along the Poudre corridor as it moves east toward the Larimer/Weld County line. The identical readings at Fort Collins and Timnath suggest minimal net gain or loss between those two points at this snapshot. Fort Collins municipal return flows — from City of Fort Collins Utilities diversions and treated wastewater discharge — contribute to lower Poudre flows in this reach and are a feature of the urban-agricultural interface unique to this corridor.

Big Thompson River:

The Loveland gauge captures combined native Big Thompson streamflow and any C-BT system releases moving through the Big Thompson corridor from Lake Estes and Olympus Dam. The falling trend at this gauge reflects the same early-meltout dynamic as the Poudre system.

Across both rivers, the falling trend at all three gauges indicates that the primary snowmelt pulse has passed. Canal companies and direct-flow irrigators on both corridors should anticipate continued flow decline toward summer baseflow levels in the coming weeks.

Seasonal Guidance

Subscribe for the full brief including reservoir storage, weather forecasts, depletion analysis, and detailed operational recommendations.

Data Sources: SNOTEL data through June 14, 2026; USGS streamflow data through June 15, 2026

Data Current As Of: Colorado Division of Water Resources

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, Northern Colorado Water Conservancy District (Northern Water — headquartered in Berthoud, Larimer County; administers C-BT Project; Horsetooth Reservoir and Carter Lake data via northernwater.org or USBR HydroMet site HRT), City of Fort Collins Utilities (municipal Poudre diversions), and Colorado Division of Water Resources Water Division 1 (Greeley office) for regulatory decisions and water rights administration.