Jerome County, ID — Water Intelligence Brief

September 7, 2026 | Free-Tier Edition

Situation Summary

North Side Canal Company deliveries are in the final weeks of the 2026 irrigation season, with upstream American Falls and Palisades reservoir storage levels — not current snowmelt — now determining what remains available for late-season alfalfa cuttings and year-round dairy operation needs. For Jerome County's dairy-dominant, storage-dependent water system, end-of-season reservoir carryover is the number that matters most heading into fall. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

Lewis Lake Divide (SNOTEL, Teton County WY — upstream Snake River headwaters indicator)

As expected at this point in the calendar, Lewis Lake Divide is fully melted out — the historical median SWE for early September is also 0.0", so this reading reflects normal seasonal conditions, not a deficit. The operational signal for Jerome County is not today's snowpack reading but rather *when* meltout occurred: across the upper Snake River headwaters, snowpack melted out 4–6 weeks ahead of the historical median meltout date in 2026, driven by the anomalous March heat wave. That early pulse accelerated inflows to Palisades and American Falls reservoirs ahead of schedule — what those reservoirs captured and carry forward is now Jerome County's primary supply question for the remainder of the season and into 2027 planning.

Streamflow Conditions

No active USGS streamflow gauges within Jerome County boundaries provide agricultural supply data. Jerome County's canal deliveries are referenced through two inherited Snake River gauges — neither physically located in the county — that serve as the definitive supply indicators for North Side Canal operations:

No gauge data was available in today's data feed for either station. Jerome County irrigators and dairy operators should contact North Side Canal Company directly for current delivery status and IDWR Water District 36 for any curtailment or priority administration updates.

Seasonal Guidance

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

Data Sources: SNOTEL data through September 6, 2026; USGS streamflow data through September 7, 2026

Data Current As Of: September 7, 2026. Idaho Department of Water Resources, Eastern Regional Office, Pocatello — (208) 525-7161.

Important Disclaimers: This brief provides automated analysis for informational purposes only. Specific numerical claims have not been independently verified. Consult official sources including North Side 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, northern Magic Valley); Idaho Department of Water Resources, Water District 36 (middle Snake River priority administration); and U.S. Bureau of Reclamation, Pacific Northwest Region (Boise office) for current American Falls and Palisades upstream storage data. Water rights administration decisions should be made only in consultation with IDWR and qualified water rights professionals.