Larimer County Water Intelligence Brief

Agricultural & Municipal Water Users — Cache la Poudre & Big Thompson Corridors

*October 5, 2026 | Free-Tier Brief*

Situation Summary

Both the Cache la Poudre and Big Thompson rivers are running at critically low late-season flows, with gauges at 5–6 cfs and trending downward — conditions that effectively mark the end of meaningful direct-flow deliveries for the 2026 irrigation season along both corridors. C-BT allotment holders and canal company members should treat this week as a transition point: late-season augmentation obligations under Water Division 1 remain active, and operators relying on Horsetooth Reservoir or Carter Lake releases for remaining deliveries should confirm scheduling directly with Northern Water. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All five SNOTEL stations monitoring Larimer County's mountain headwaters are reporting minimal to no snow water equivalent (SWE) as of October 4, 2026 — a condition that is consistent with normal seasonal expectations at this point in the calendar, when the historical median SWE for these dates is also at or near 0.0".

Big Thompson headwaters (Rocky Mountain National Park corridor):

Cache la Poudre headwaters:

The trace readings at Bear Lake, Willow Park, Joe Wright, and Deadman Hill, and the zero reading at Hourglass Lake, reflect the seasonal baseline — not a below-normal anomaly for early October. The relevant 2026 snowpack story is one of timing: an anomalous March heat wave caused mountain snowpack across both the Big Thompson and Poudre headwaters to melt out 4–6 weeks ahead of the historical median meltout date, compressing the spring runoff window and reducing total seasonal delivery volumes for both river systems. That event is now background context. New snowpack accumulation for water year 2027 is the forward-looking indicator to watch as October progresses.

Streamflow Conditions

Both river systems are reporting low, falling flows consistent with end-of-season conditions in an early-meltout year.

Big Thompson River:

The Loveland gauge captures combined native Big Thompson flow and any C-BT system releases from Olympus Dam. At 6 cfs and falling, this gauge signals that deliveries to the Loveland agricultural reach are at or below meaningful irrigation thresholds. Big Thompson irrigators east of Loveland should treat current flows as effectively non-irrigable for most crop applications.

Cache la Poudre River:

The Fort Collins gauge reflects combined native Poudre flow and municipal return flows from City of Fort Collins Utilities — at 5 cfs, even the augmenting effect of urban return flows is insufficient to support meaningful direct diversions. The Timnath gauge, downstream near the Larimer/Weld County line, shows identical flow, indicating minimal additional tributary contribution between Fort Collins and Timnath. Canal companies along the lower Poudre corridor should note that the Wild and Scenic designation constrains future infrastructure responses on the designated reach — current low-flow conditions underscore the importance of in-county storage at Horsetooth and Carter Lake as the operational buffer.

Seasonal Guidance

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

Data Sources: SNOTEL data through October 4, 2026; USGS streamflow data through October 5, 2026

Data Current As Of: October 5, 2026 | 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.