Cassia County, ID — Water Intelligence Brief

August 17, 2026 | Free-Tier Edition

Situation Summary

Cassia County enters the final stretch of the 2026 irrigation season with snowpack-derived runoff fully exhausted across all monitored SNOTEL stations — an expected mid-August condition, though the 2026 season was defined by snowmelt completing 4–6 weeks ahead of the historical median meltout date, compressing the spring recharge window significantly. Both the Snake River corridor (Burley/Rupert area) and the Raft River Valley (Oakley/Malta area) are now fully dependent on stored and diverted supplies with no supplemental snowmelt available. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All three SNOTEL stations monitored for the Cassia County region are reporting zero snow water equivalent (SWE) and zero snow depth as of August 16, 2026 — a normal condition for this date in mid-August, when the mountain snowpack has fully melted. No percent-of-median figure is shown for any station because the historical median SWE for this calendar date is also 0.0", meaning current readings are at seasonal norms for this point in the year.

Station readings (August 16, 2026):

The operationally significant snowpack story for 2026 is not current SWE — it is meltout timing. All stations melted out 4–6 weeks ahead of the historical median meltout date due to the anomalous March 2026 heat event across the Mountain West. That early meltout accelerated spring runoff into a narrower window, reducing the sustained streamflow contribution that typically carries Snake River canal systems and Raft River surface supplies into mid-summer. That pulse has passed. No further snowmelt contribution should be expected for the remainder of the 2026 irrigation season.

Streamflow Conditions

Two active USGS gauges provide in-county streamflow intelligence for Cassia County's two distinct agricultural zones.

Cassia Creek below Blacksmith Creek (Snake River Basin): 6 cfs, rising — August 17, 2026

Cassia Creek is a minor tributary within the Snake River Basin. The current reading of 6 cfs with a rising trend is a modest positive signal but reflects a small drainage — this gauge serves as a local watershed indicator rather than a supply volume of significance to large-scale irrigated agriculture. Users in the Cassia Creek drainage should note the rising trend and monitor whether it is sustained.

Raft River above Onemile Creek near Malta (13078000): 2 cfs, stable — August 17, 2026

This gauge is the primary streamflow indicator for the Raft River Valley (southern Cassia County — Oakley, Malta, Elba, Almo area). At 2 cfs and stable, the Raft River is at a characteristically low late-season level consistent with its modest drainage and limited baseflow. Raft River Valley ranchers and irrigators should treat this as a minimal-supply condition. Hay and alfalfa operations dependent on Raft River surface diversions should manage remaining irrigation demand carefully, as no meaningful flow increase from snowmelt is forthcoming this season.

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 reference points outside the county. Contact Burley Irrigation District directly for current diversion status.

Seasonal Guidance

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

Data Sources: SNOTEL data through August 16, 2026; USGS streamflow data through August 17, 2026.

Data Current As Of: August 17, 2026. SNOTEL data provided by NRCS National Water and Climate Center. Streamflow data provided by USGS National Water Information System.

Important Disclaimers: This brief provides automated analysis for informational purposes only. Specific numerical claims have not been independently verified. Consult official sources for regulatory and operational decisions, including: Burley Irrigation District (primary Snake River corridor delivery infrastructure); IDWR Water District 36, Burley office (water rights administration, call status, ESPA monitoring); USBR Pacific Northwest Region, Boise office (American Falls Reservoir and Palisades Reservoir upstream storage context); and IDWR Eastern Regional Office, Pocatello — (208) 525-7161 (Raft River Valley water right administration and regional groundwater questions). This brief does not constitute legal, engineering, or water rights advice. Contact the appropriate agency before making operational decisions based on this information.