Larimer County Water Intelligence Brief

June 29, 2026 | Free-Tier Edition

Situation Summary

The two-river system serving Larimer County — the Cache la Poudre and Big Thompson — is operating on declining late-season flows following an anomalous early-melt year in which snowpack across both watersheds melted out 4–6 weeks ahead of the historical median meltout date. Horsetooth Reservoir and Carter Lake, Larimer County's primary in-county C-BT storage facilities, are now carrying the seasonal supply burden that snowpack would normally still be contributing through late June and into July. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All five SNOTEL stations monitoring Larimer County's headwaters are reporting at or near zero snow water equivalent as of June 28, 2026 — a condition that is normal for this calendar date, but which arrived 4–6 weeks earlier than the historical median meltout date due to the anomalous March heat wave.

Big Thompson headwaters (Rocky Mountain National Park corridor):

These two stations are the primary snowpack indicators for the Big Thompson delivery corridor. Bear Lake is fully melted out. Willow Park carries a trace 0.2" SWE — a negligible residual at this date with no depth reading, indicating isolated remnant patches rather than meaningful snowpack. No percent-of-median is reported for either station, meaning the median SWE for this date is also 0.0"; the stations are at normal seasonal condition for late June. The supply signal is not current deficit — it is the absence of snowmelt contribution that would normally still be running through this period.

Cache la Poudre headwaters:

Joe Wright's 0.1" SWE with 3.0" snow depth suggests very wet, dense remnant snow — likely shaded north-facing terrain holding isolated late patches. Deadman Hill's 1.0" depth with 0.0" SWE reflects saturated or icy surface conditions with no meaningful water content. Hourglass Lake is fully melted out. As with the Big Thompson stations, no percent-of-median is reported, confirming these readings reflect normal late-June seasonal conditions rather than below-normal snowpack. The 2026 concern is timing: snowmelt that typically sustains Poudre and Big Thompson flows through early-to-mid July has already concluded.

Streamflow Conditions

Both river systems are showing falling flows as of June 29, consistent with the exhaustion of snowmelt contribution.

Big Thompson River at Loveland (06741510): 82 cfs, falling

This gauge captures combined native Big Thompson flow and C-BT releases through the Olympus Dam system. At 82 cfs and falling, the Loveland agricultural reach is receiving meaningfully reduced flow relative to peak irrigation season demand. Big Thompson irrigators drawing below this gauge should monitor delivery conditions closely.

Cache la Poudre River at Fort Collins (06752260): 54 cfs, falling

This in-county gauge on the Poudre reflects conditions through the Fort Collins reach, inclusive of municipal diversions and return flows. At 54 cfs and falling, mid-summer agricultural demand pressure on the Poudre corridor is building.

Cache la Poudre River above Boxelder Creek near Timnath (06752280): 35 cfs, falling

This downstream gauge captures residual Poudre flow after Fort Collins municipal diversions and agricultural withdrawals upstream. At 35 cfs — roughly two-thirds the flow at the Fort Collins gauge — the Timnath reach reflects the cumulative draw on the lower Poudre system. All three gauges are on falling trends, with no snowmelt input remaining to reverse course naturally.

Seasonal Guidance

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Data Sources: SNOTEL data through June 28, 2026; USGS streamflow data through June 29, 2026

Data Current As Of: June 29, 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, 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.