Larimer County Water Intelligence Brief

September 7, 2026 | Free-Tier Edition

Situation Summary

Both the Cache la Poudre and Big Thompson rivers are delivering late-season flows well into the low end of what Larimer County irrigators and canal companies typically manage in early September, with the Poudre trending downward at both in-county gauges and the Big Thompson holding steady in the Loveland reach. For alfalfa, hay, and livestock operations drawing from either corridor, this is the week to confirm remaining delivery allocations with your ditch company and assess whether late-season cutting schedules are still viable under current conveyance conditions. Reservoir storage data for Horsetooth and Carter Lake, along with 7-day forecast details and C-BT delivery outlook, 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 September 6 — a normal seasonal condition for this date, as median SWE for early September is also 0.0" at these elevations. No station is below a percent-of-median benchmark, because the benchmark itself is zero this time of year.

The relevant 2026 context is timing, not current depth: stations across both the Big Thompson and Cache la Poudre headwaters melted out approximately 4–6 weeks ahead of the historical median meltout date, driven by the anomalous March heat wave. That early meltout is a completed event — its significance lies in what it meant for spring and summer runoff timing and volume, not for conditions on the ground today.

Station-by-station readings (September 6):

Bear Lake's 1.0" snow depth with 0.0" SWE likely reflects a trace accumulation with negligible water content — not a meaningful supply signal. Joe Wright's 0.2" SWE is a minor isolated reading insufficient to influence streamflow. No meaningful snowmelt contribution to either river system should be expected from the headwaters at this stage of the season.

Streamflow Conditions

Big Thompson River at Loveland (USGS 06741510): 45 cfs, stable as of September 7. This gauge captures combined native Big Thompson flow plus any C-BT releases moving through Olympus Dam — making it the primary operational indicator for Big Thompson corridor irrigators in the Loveland agricultural reach. At 45 cfs and holding steady, conditions are tight but currently maintaining delivery. Irrigators drawing from the Big Thompson below Loveland should monitor closely for any shift from stable to falling trend.

Cache la Poudre at Fort Collins (USGS 06752260): 11 cfs, falling as of September 7. This in-county gauge reflects upper Poudre delivery conditions through Fort Collins, including municipal diversions by City of Fort Collins Utilities. At 11 cfs and trending downward, the lower Poudre is in a constrained late-season posture. Fort Collins municipal return flows provide some augmentation to downstream agricultural users, but with the mainstem falling, the buffer is narrowing.

Cache la Poudre above Boxelder Creek near Timnath (USGS 06752280): 9 cfs, falling as of September 7. The Timnath gauge sits near the Larimer-Weld county line and represents the Poudre's condition as it exits Larimer County. At 9 cfs falling, senior water rights holders in the lower Poudre corridor and any users dependent on the Poudre's contribution eastward into Weld County are operating under minimal native flow conditions. Canal companies with direct-flow rights on the lower Poudre should confirm administrative status with Water Division 1.

Across both river systems, the directional signal is clear: Big Thompson is holding while the Poudre is declining. The divergence likely reflects C-BT release management on the Big Thompson side. Users on the Poudre corridor face tighter conditions entering the final weeks of the irrigation season.

Seasonal Guidance

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Data Sources: SNOTEL data through September 6, 2026; USGS streamflow data through September 7, 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 Northern Colorado Water Conservancy District (Northern Water — headquartered in Berthoud, Larimer County; Horsetooth Reservoir and Carter Lake data via northernwater.org or USBR HydroMet site HRT), City of Fort Collins Utilities, Colorado Division of Water Resources Water Division 1 (Greeley office), and your local ditch or canal company for regulatory decisions and water rights administration.