Cassia County Water Intelligence Brief

September 28, 2026 | Free-Tier Edition

Situation Summary

Streamflows in Cassia County are at late-season levels consistent with end-of-irrigation expectations: Cassia Creek is registering 4 cfs and falling, while the Raft River near Malta is at 11 cfs and rising — a modest positive signal for southern county ranching operations heading into fall. Burley Irrigation District delivery status for the Snake River corridor should be confirmed directly with the district, as no active USGS Snake River gauge exists within Cassia County boundaries and upstream conditions govern supply availability for contracted potato, beet, and processing industry users. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All three SNOTEL stations reporting for the Cassia County area are at end-of-season baseline:

No percent-of-median figures are shown for any station, which is expected — the median SWE for late September at these elevations is also effectively 0.0", meaning current readings reflect normal end-of-season conditions for this calendar date, not a deficit signal. The relevant 2026 snowpack story is timing: across these stations, snowpack melted out approximately 4–6 weeks ahead of the historical median meltout date, driven by the anomalous March heat wave. That early meltout is background context for understanding the 2026 irrigation season's supply trajectory — it is not a current snowpack concern.

New accumulation season begins in the coming weeks. First meaningful SWE readings at these stations typically emerge in October–November.

Streamflow Conditions

Cassia Creek Below Blacksmith Creek (09/28): 4 cfs, falling trend. This small tributary system in the northern county is at a low late-season reading consistent with end-of-irrigation conditions. The falling trend indicates continued seasonal recession with no significant recharge event in recent days.

Raft River Above Onemile Creek Near Malta (13078000, 09/28): 11 cfs, rising trend. This is the primary in-county streamflow indicator for the Raft River Valley (south county — Oakley, Malta, Almo area). At 11 cfs and rising, the gauge is showing a modestly positive signal for late September — the rising trend may reflect recent local precipitation or reduced upstream consumptive demand as the irrigation season winds down. For southern Cassia County ranchers and hay producers, this reading suggests some continued surface water availability, though volumes remain modest and characteristic of the Raft River's limited-flow character in this reach.

Snake River Corridor note: No active USGS Snake River gauge exists within Cassia County boundaries — the Snake River near Burley (USGS 13085045) is discontinued. Supply assessment for the Burley Irrigation District service area relies on upstream gauges outside the county. Cassia County Snake corridor irrigators, potato operations, and Amalgamated Sugar's Burley factory should contact Burley Irrigation District directly for current delivery status.

Seasonal Guidance

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

Data Sources: SNOTEL data through September 27, 2026; USGS streamflow data through September 28, 2026.

Data Current As Of: September 28, 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, Idaho Department of Water Resources (IDWR — Water District 36, Burley office), Burley Irrigation District, and U.S. Bureau of Reclamation Pacific Northwest Region (Boise office) for current delivery status, call administration, and upstream reservoir storage data before making operational or regulatory decisions.