Larimer County Water Intelligence Brief

July 6, 2026 | Free Tier

Situation Summary

The two-river system serving Larimer County — the Cache la Poudre and the Big Thompson — is operating under late-season low-flow conditions, with both rivers reflecting the consequences of an anomalous March heat wave that drove snowmelt across the Big Thompson headwaters and Poudre headwaters 4–6 weeks ahead of historical median meltout dates. Horsetooth Reservoir and Carter Lake, Larimer County's primary in-county C-BT storage facilities, and current C-BT allotment delivery status are the key variables shaping the operational outlook for the remainder of the irrigation season. 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 — across both the Big Thompson and Cache la Poudre corridors — are reporting 0.0" snow water equivalent (SWE) as of July 5, 2026. This is the expected seasonal condition for early July; because the historical median SWE for these stations at this date is also 0.0", these readings do not indicate below-normal snowpack relative to today's calendar position.

The meaningful signal for 2026 is timing, not current depth. Bear Lake (9,490 ft, Big Thompson headwaters) and Willow Park (Big Thompson corridor) both report 0.0" SWE and 0.0" depth. These stations are the primary snowpack indicators for the Big Thompson delivery corridor and Rocky Mountain National Park headwaters. Joe Wright (Cache la Poudre headwaters) shows a residual 0.1" SWE with 4.0" snow depth — a trace signal indicating the very last remnant of the snowpack at elevation, consistent with near-complete meltout. Deadman Hill and Hourglass Lake, also monitoring the Poudre headwaters, report 0.0" SWE and 0.0" depth.

Taken together, these five stations confirm that both river systems' snowpack contributions for 2026 were delivered to the stream system well ahead of schedule. The operational consequence is that runoff-driven streamflow support has already ended — any remaining flow in the Poudre and Big Thompson is now driven by baseflow, groundwater discharge, and managed releases rather than continuing snowmelt input.

Streamflow Conditions

Streamflow across both river systems is low and falling as of July 6, 2026.

Big Thompson River at Loveland (USGS 06741510): 74 cfs, falling. This gauge captures combined native Big Thompson flow and C-BT system releases through the Loveland agricultural reach — it is the primary supply indicator for Big Thompson corridor irrigators east of Loveland. At 74 cfs and falling, conditions reflect the post-meltout transition to baseflow-dominated supply.

Cache la Poudre River at Fort Collins (USGS 06752260): 3 cfs, falling. This in-county gauge, located within the Fort Collins city reach, reflects sharply diminished mainstem Poudre flow. At 3 cfs, meaningful direct-flow diversions from the Poudre mainstem at this location are essentially absent. Fort Collins municipal return flows may represent a notable share of what remains in the channel at this stage.

Cache la Poudre River above Boxelder Creek near Timnath (USGS 06752280): 1 cfs, falling. At the Larimer/Weld County line, Poudre mainstem flow has effectively reached minimum conditions. Canal company members and Water Division 1 augmentation plan holders on the lower Poudre should treat this reading as confirmation that direct-flow rights are not being met from the river at current levels.

The contrast between the two river systems is notable: the Big Thompson at 74 cfs reflects the managed release character of the C-BT delivery infrastructure, while the Poudre at 1–3 cfs reflects an unmanaged, native-flow-dependent reach that has exhausted its runoff pulse. Irrigators relying on direct Poudre diversions without storage or augmentation backing are operating in a critically constrained environment.

Seasonal Guidance

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Data Sources: SNOTEL data through July 5, 2026; USGS streamflow data through July 6, 2026.

Data Current As Of: July 6, 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 storage data available 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. This brief does not constitute legal, engineering, or water rights advice.