Jerome County, ID — Water Intelligence Brief

August 31, 2026 | Free-Tier Edition

Situation Summary

North Side Canal Company deliveries are in the final weeks of the 2026 irrigation season, with late-season alfalfa cutting schedules and year-round dairy operation water demand now dependent almost entirely on upstream reservoir carryover from American Falls and Palisades. Reservoir storage data and 7-day forecast details are available in the full brief. Jerome County's storage-dominant supply profile makes late-season reservoir drawdown — not current Snake River flows — the decisive variable for dairy operators and alfalfa growers managing the remainder of the irrigation season.

Snowpack Conditions

Lewis Lake Divide (SNOTEL, Teton County WY, 7,880 ft.) — August 30, 2026:

Snow water equivalent: 0.0" | Snow depth: 0.0"

Lewis Lake Divide — the upstream Continental Divide station governing inflow to Jackson Lake, Palisades Reservoir, and ultimately American Falls — is fully melted out, which is normal for this point in the calendar. The median SWE for late August at this station is also 0.0", so current conditions reflect expected seasonal meltout, not a below-normal snowpack reading. The operational signal from this station is timing, not current deficit: the 2026 snowpack melted out 4–6 weeks ahead of the historical median meltout date, meaning the seasonal pulse of snowmelt inflow to Palisades arrived earlier and concluded earlier than normal. For Jerome County — where 80% of irrigation supply originates from upstream reservoir storage — what matters now is how much of that early runoff was captured in Palisades and American Falls. Snowpack monitoring is no longer the relevant supply indicator for the remainder of the 2026 season.

Streamflow Conditions

No active USGS streamflow gauges within Jerome County boundaries provide agricultural supply data. Jerome County water managers rely on two inherited Snake River reference points: the Snake River at Milner Dam (USGS 13087995, pre-diversion indicator) and the Snake River near Twin Falls (USGS 13090500, basin integrator). Neither gauge is physically located in Jerome County, but both are the definitive supply references for North Side Canal deliveries. No gauge data was available in this reporting cycle. Near-zero or zero flow below Milner Dam during active irrigation season is normal operating condition — the Milner diversion captures essentially the full Snake River flow for both the Twin Falls Canal Company (south bank) and North Side Canal Company (north bank). This is canal infrastructure functioning as designed, not a crisis signal. Supply anomalies for Jerome County irrigators are best read through above-Milner flow levels and upstream reservoir storage status — not below-Milner readings.

Seasonal Guidance

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

Data Sources: SNOTEL data through August 30, 2026; USGS streamflow data through August 31, 2026.

Data Current As Of: August 31, 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), Northside Canal Company (primary north-bank diverter at Milner Dam, serving approximately 85,000 acres across Jerome, Lincoln, and adjacent counties), A&B Irrigation District (USBR Bureau of Reclamation project serving northern Magic Valley area in Jerome and Lincoln counties), and U.S. Bureau of Reclamation, Pacific Northwest Region (Boise office — for American Falls and Palisades upstream storage context) for regulatory decisions and water rights administration.