Cassia County Water Intelligence Brief

June 22, 2026 | Free-Tier Edition

Situation Summary

The 2026 season is defined by early meltout — snowpack across the upper Snake River basin melted out 4–6 weeks ahead of the historical median meltout date, compressing the natural recharge window for both Snake River corridor deliveries and Raft River Valley surface supplies. Cassia County's two distinct agricultural zones — the Snake River corridor (Burley/Rupert processing hub) and the Raft River Valley (Oakley/Malta ranching zone) — are both operating under tightening late-season supply conditions as of mid-June. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All three SNOTEL stations reporting for Cassia County's source watersheds show complete meltout as of June 21, 2026:

At this point in the calendar (late June), a median SWE of 0.0" is expected at all three stations — the stations are at their normal seasonal condition for this date. The critical 2026 story is not today's readings but meltout timing: all stations reached zero SWE 4–6 weeks earlier than the historical median meltout date, meaning the seasonal pulse of snowmelt runoff that recharges the Snake River system and drives early-season canal delivery capacity arrived and passed well ahead of schedule. No additional snowmelt contribution to streamflow or aquifer recharge should be anticipated from these stations for the remainder of the 2026 season.

Streamflow Conditions

Two USGS gauges provide in-county surface water intelligence for Cassia County's distinct zones:

Cassia Creek Below Blacksmith Creek, ID — reading 8 cfs, falling as of June 22. Cassia Creek is a minor tributary in the Snake River corridor portion of the county. The falling trend at this point in the season is consistent with post-meltout recession; no snowmelt pulse remains to sustain or rebuild flows. This gauge is a local tributary indicator, not a Snake River delivery indicator.

Raft River Above Onemile Creek Near Malta, ID (USGS 13078000) — reading 1 cfs, falling as of June 22. This is the primary surface water supply indicator for the Raft River Valley (southern Cassia County — Oakley, Malta, Almo, Elba area). At 1 cfs and falling, the Raft River is at the low end of its seasonal range. Raft River Valley ranchers and alfalfa irrigators dependent on surface water diversions should treat this as a critically constrained supply signal for the remainder of the irrigation season. The Raft River system is structurally modest — flows in the 1–10 cfs range at this gauge are the operational reality of a ranching-scale watershed, not a large irrigated system — but 1 cfs falling leaves minimal margin for diversion-dependent operations.

Important note on Snake River corridor supply: 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 indicators at Milner and near Twin Falls. Those upstream signals, combined with American Falls and Palisades Reservoir storage context, are the governing variables for Burley Irrigation District delivery capacity — covered in the full brief.

Seasonal Guidance

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

Data Sources: SNOTEL data through June 21, 2026; USGS streamflow data through June 22, 2026.

Data Current As Of: June 22, 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; Burley district office for Cassia County water rights), Burley Irrigation District (primary delivery infrastructure for the Snake River corridor), and U.S. Bureau of Reclamation, Pacific Northwest Region (Boise office) for American Falls Reservoir and Palisades Reservoir upstream storage context. Raft River Valley users should contact IDWR Water District 36 (Burley office) for surface water call status and any local storage information for the Oakley area. This brief does not constitute water rights legal advice — consult IDWR or a licensed water rights consultant for regulatory decisions.