Cassia County Agricultural Water Intelligence Brief

June 29, 2026 | Free-Tier Edition

Situation Summary

Snowpack across the headwater stations serving Cassia County's water supply areas has fully melted out, with all SNOTEL stations recording zero snow water equivalent — a condition that arrived 4–6 weeks ahead of the historical median meltout date due to the anomalous March heat wave across the Mountain West. Streamflow on both the Raft River near Malta and Cassia Creek below Blacksmith Creek reflects this advanced seasonal transition, with in-county indicators showing modest flows appropriate to late-June conditions. Reservoir storage data for American Falls and Palisades — the upstream facilities governing Snake River supply to Burley Irrigation District — and 7-day forecast details are available in the full brief.

Snowpack Conditions

All three SNOTEL stations reporting for Cassia County's supply area show complete meltout as of June 28, 2026:

For late June, zero SWE at these stations is the normal seasonal condition — the median SWE for this calendar date is also 0.0", so these readings do not indicate below-normal snowpack *today*. The meaningful signal for 2026 is timing: these stations melted out 4–6 weeks ahead of the historical median meltout date. That earlier-than-normal meltout means peak runoff pulse has already passed, and the Snake River system is now dependent on stored water in upstream reservoirs rather than ongoing snowmelt contributions. For Cassia County's Snake River corridor, that shifts the operational focus squarely to American Falls and Palisades Reservoir storage levels and Burley Irrigation District delivery management for the remainder of the season.

Streamflow Conditions

Two USGS gauges provide in-county streamflow data for Cassia County's two distinct agricultural zones:

Raft River Valley (south county):

Raft River above Onemile Creek near Malta (13078000): 2 cfs, stable as of June 29. This reading reflects the Raft River Valley's character as a limited-flow system — flows in the 1–10 cfs range at this gauge are typical for the late irrigation season. At 2 cfs stable, the Raft River is providing minimal supply for the Oakley-area ranching and hay operations that depend on it. Ranchers and irrigators in the Malta, Oakley, and Elba areas should treat current Raft River flows as a tight supply environment with little margin for increased demand.

Cassia Creek (north county tributary zone):

Cassia Creek below Blacksmith Creek (12 cfs, rising as of June 29): This rising signal on Cassia Creek is a localized indicator for the tributary drainage rather than a Snake River mainstem supply measure. The rising trend warrants monitoring but should not be read as a broad improvement in Snake River corridor supply.

Important note for Snake River corridor users: No active USGS Snake River gauge exists within Cassia County boundaries — the Snake River near Burley gauge (13085045) is discontinued. Supply assessment for the Burley Irrigation District service area relies on upstream gauges at Milner and near Twin Falls. Snake River flow near zero below Milner Dam during peak irrigation season is normal canal operations, not a supply failure signal. Upstream American Falls and Palisades storage levels are the meaningful late-season supply variable for Burley Irrigation District users.

Seasonal Guidance

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

Data Sources: SNOTEL data through June 28, 2026; USGS streamflow data through June 29, 2026.

Data Current As Of: June 29, 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 — administers Water District 36, the middle Snake River priority system; Burley district office), Burley Irrigation District (primary delivery infrastructure for the Snake River corridor in Cassia County), and U.S. Bureau of Reclamation, Pacific Northwest Region (Boise office — for American Falls Reservoir and Palisades Reservoir upstream context) for regulatory decisions and water rights administration.