Water Intelligence Brief · Archive

Larimer County, CO

August 10, 2026

Larimer County Water Intelligence Brief

August 10, 2026 | Free-Tier Edition

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

Situation Summary

Larimer County's two-river system — the Cache la Poudre and the Big Thompson — is operating on stored water and late-summer baseflows following a 2026 snowpack season defined by an anomalous March heat wave that drove meltout 4–6 weeks ahead of the historical median across all five headwater SNOTEL stations. With Horsetooth Reservoir and Carter Lake serving as the county's primary in-county storage buffers and late-season C-BT deliveries now governing agricultural supply on the Big Thompson corridor, the supply picture entering the final weeks of the irrigation season is tight. 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 report conditions consistent with normal late-summer snowpack absence. Critically, the 2026 story is not today's readings — it is when meltout occurred.

Big Thompson Headwaters (Rocky Mountain National Park corridor):

Bear Lake (9,490 ft) — August 9: SWE 0.0", snow depth 1.0". The trace depth reading likely reflects instrument artifact or isolated shaded snow remnant rather than a meaningful snowpack. SWE of 0.0" is normal for this station at this calendar date.

Willow Park (10,710 ft) — August 9: SWE 1.0", snow depth 0.0". A notable reading — a small SWE value with zero reported depth is an unusual combination and may reflect sensor conditions. No percent-of-median figure is provided, meaning the median SWE for this date is also near zero; this reading does not indicate anomalous accumulation. Willow Park is the primary high-elevation indicator for Big Thompson River headwater contribution.

Both Big Thompson headwater stations melted out 4–6 weeks ahead of the historical median meltout date, meaning the spring runoff pulse that feeds summer streamflow and C-BT fill operations concluded significantly earlier than a typical year. The implications for late-season Big Thompson flows and C-BT delivery scheduling are a paid-tier analysis item.

Cache la Poudre Headwaters:

Joe Wright (approximately 10,000 ft) — August 9: SWE 0.0", snow depth 5.0". A snow depth of 5 inches with 0.0" SWE suggests dense, highly metamorphosed late-season snow or possible instrument lag. No SWE contribution to streamflow is indicated. Joe Wright monitors the upper Poudre corridor near the Cameron Pass area and is the primary Poudre headwater SNOTEL reference.

Deadman Hill — August 9: SWE 0.0", snow depth 0.0". Full meltout confirmed at this station. Normal condition for this date.

Hourglass Lake — August 9: SWE 0.0", snow depth 0.0". Full meltout confirmed. Normal condition for this date.

All three Cache la Poudre headwater stations also melted out 4–6 weeks ahead of the historical median meltout date. No station reports a percent-of-median figure, confirming that today's 0.0" SWE readings are within normal seasonal range for August 9 — the supply signal is in the timing of meltout, not the current readings themselves.

Streamflow Conditions

Larimer County's two river systems are showing markedly different late-season conditions, reflecting both their distinct hydrology and the role of C-BT infrastructure on the Big Thompson corridor.

Big Thompson River at Loveland (USGS 06741510) — August 10:

Flow is 81 cfs and rising. This gauge captures combined native Big Thompson streamflow and C-BT releases delivered through the Adams Tunnel and Lake Estes system before entering the Loveland agricultural reach. The rising trend is noteworthy at this stage of the season and may reflect managed C-BT releases rather than natural runoff recovery — the 4–6 week early meltout timing makes a natural flow increase from snowmelt unlikely in August. Big Thompson irrigators drawing from the Loveland reach should note this rising signal while tracking Northern Water delivery schedules directly for operational planning.

Cache la Poudre River at Fort Collins (USGS 06752260) — August 10:

Flow is 3 cfs and falling. This in-county gauge on Colorado's only federally designated Wild and Scenic River reflects conditions on the main Poudre channel through Fort Collins. At 3 cfs and declining, the river is running at minimal late-season levels. Municipal diversions by City of Fort Collins Utilities and senior agricultural rights upstream are the dominant demand on available flow. The Wild and Scenic designation constrains any new structural supply options on the designated corridor, making stored water and augmentation plan management the operative tools for downstream users.

Cache la Poudre River above Boxelder Creek near Timnath (USGS 06752280) — August 10:

Flow is 2 cfs and falling. This gauge, also physically in Larimer County near the Larimer/Weld county line, shows further attenuation of Poudre flows below Fort Collins. At 2 cfs and falling, available natural flow for junior direct-flow rights on the lower Poudre is effectively exhausted. Canal companies holding senior Poudre rights should be coordinating with the Water Division 1 Division Engineer office (Greeley) on current priority administration. Augmentation plan holders should verify that replacement obligations are being met given the minimal streamflow available.

Seasonal Guidance

Check Northern Water's operational updates at northernwater.org for current C-BT delivery scheduling, Horsetooth Reservoir status, and Carter Lake conditions — Northern Water is headquartered in Berthoud and is the primary authority for C-BT allotment holder questions.

Contact Colorado Division of Water Resources, Water Division 1 (Greeley office) to verify current priority administration on both the Cache la Poudre and Big Thompson systems, particularly for junior direct-flow rights and augmentation plan compliance.

Canal company members along the Poudre corridor — including Water Supply and Storage Company, New Cache la Poudre Irrigating Company, and North Poudre Irrigation Company — should contact their ditch company superintendents directly for current delivery pro-ration status and end-of-season scheduling.

City of Fort Collins Utilities (Fort Collins Water Resources) is the contact for questions about municipal Poudre diversions and urban return flow timing that affect downstream agricultural supply on the lower Poudre.

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

Data Sources: SNOTEL data through August 9, 2026; USGS streamflow data through August 10, 2026.

Data Current As Of: August 10, 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.

Data & Disclaimers

Sources: NRCS SNOTEL network · USGS National Water Information System · National Weather Service

This brief provides automated analysis for informational purposes only. Consult official sources including your local water district and state Division of Water Rights for regulatory decisions. This document does not constitute legal, regulatory, or engineering advice.

Other Issues

Stay Updated

Water intelligence, delivered.

Free seasonal updates on water conditions across the Mountain West.

Free · Delivered when reports publish