Larimer County Water Intelligence Brief

August 3, 2026 | Free-Tier Edition

*Cache la Poudre & Big Thompson Corridors | C-BT System | Water Division 1*

Situation Summary

Larimer County's two-river system — the Cache la Poudre and Big Thompson — is operating on late-summer baseflows following an anomalous 2026 snowpack season in which mountain snowpack melted out 4–6 weeks ahead of the historical median meltout date across all five headwater SNOTEL stations. In-county C-BT storage at Horsetooth Reservoir and Carter Lake, along with the C-BT delivery schedule administered by Northern Water, are now the dominant supply variables for both agricultural irrigators and municipal users through the remainder of the season. Reservoir storage data, 7-day forecast details, and operational recommendations are available in the full brief.

Snowpack Conditions

All five SNOTEL stations monitoring Larimer County's headwater zones reported zero or near-zero snowpack as of August 2, 2026 — consistent with the county's early-meltout story for this season.

Big Thompson Headwaters (Rocky Mountain National Park corridor):

Bear Lake and Willow Park are the primary snowpack indicators for the Big Thompson delivery corridor and the Adams Tunnel transbasin system. Both stations melted out 4–6 weeks ahead of the historical median meltout date. The 1.0" SWE reading at Willow Park with 0.0" depth is an instrument artifact consistent with end-of-season residual signal — no meaningful snowpack exists at either station. No percent-of-median figure is shown for either station, meaning the August 2 median SWE is also 0.0" — these stations are at their normal seasonal condition for this point in the calendar.

Cache la Poudre Headwaters:

The Poudre headwater stations tell a similar story. Joe Wright's anomalous 6.0" snow depth reading with 0.0" SWE indicates residual compacted snow or ice with no measurable free-water equivalent — not meaningful snowmelt runoff potential. Deadman Hill and Hourglass Lake show completely bare conditions. As with the Big Thompson stations, no percent-of-median figure is reported for any of these stations, meaning the August 2 median is also 0.0" — current readings reflect normal late-season conditions, not below-normal snowpack. The critical 2026 signal is meltout timing: the Poudre headwater snowpack concluded 4–6 weeks earlier than historical median, compressing the spring runoff window significantly and pulling forward demand on stored water supplies.

Bottom line: No snowmelt contribution is available from either river system. Larimer County's water supply picture for the remainder of the 2026 irrigation season depends entirely on stored water — principally Horsetooth Reservoir and Carter Lake — and whatever residual native streamflow remains in the two river corridors.

Streamflow Conditions

Big Thompson River at Loveland (USGS 06741510): 71 cfs — Stable (August 3)

The Loveland gauge captures the combined signature of native Big Thompson flow and C-BT releases through the Olympus Dam system. At 71 cfs, the Big Thompson is delivering a modest but stable late-summer flow into the Loveland agricultural reach. The stable trend is notable — it suggests C-BT release management is currently sustaining flows rather than allowing rapid decline. This gauge is the primary supply indicator for Big Thompson corridor irrigators south and east of Loveland.

Cache la Poudre River at Fort Collins (USGS 06752260): 22 cfs — Falling (August 3)

The Fort Collins gauge is physically in Larimer County and reflects the integrated Poudre system: native headwater flows, upstream agricultural diversions, and municipal return flows from Fort Collins Utilities. At 22 cfs and falling, the upper Poudre reach is in clear late-summer recession. The falling trend warrants attention for irrigators diverting on the Fort Collins reach, particularly those with junior priority dates. Fort Collins municipal return flows continue to contribute to the lower Poudre system, partially offsetting upstream diversions.

Cache la Poudre River Above Boxelder Creek near Timnath (USGS 06752280): 9 cfs — Falling (August 3)

The Timnath gauge, near the Larimer/Weld County line, shows the Poudre system at its lowest and most stressed point in Larimer County. At 9 cfs and falling, available native flow for downstream diversions is extremely limited. Canal companies and direct-flow appropriators on the lower Poudre corridor — including those operating under augmentation plan obligations in Water Division 1 — should be treating this gauge as a critical operational signal. Senior rights on the lower Poudre date to the 1860s and 1870s; junior appropriators should expect limited or no direct-flow availability at current levels.

Bottom line: The Big Thompson corridor shows stable late-summer conditions supported by C-BT release management. The Cache la Poudre corridor is in active late-season decline, with the Timnath reach at critically low levels. The contrast between these two systems reflects the structural difference in Larimer County water supply: the Big Thompson is buffered by C-BT infrastructure; the Poudre depends more directly on native flow conditions.

Seasonal Guidance

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

Data Sources: SNOTEL data through August 2, 2026; USGS streamflow data through August 3, 2026

Data Current As Of: August 3, 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.