Jerome County, ID — Water Intelligence Brief

October 12, 2026 | Free-Tier Edition

Situation Summary

As irrigation season winds down across Jerome County, North Side Canal Company deliveries are transitioning toward end-of-season operations — a normal pattern for mid-October, when alfalfa cutting schedules are completing final harvests and dairy support acreage shifts to dormancy preparation. For Jerome County's dairy operators and alfalfa growers, the relevant question now is carryover storage entering winter: American Falls and Palisades reservoir levels heading into the off-season will determine supply availability when North Side Canal reopens in spring. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

Lewis Lake Divide (SNOTEL, Teton County WY — upper Snake River headwaters):

As of October 11, Lewis Lake Divide shows 0.1" SWE and 0.0" snow depth. No percent-of-median figure is provided, indicating the median SWE for this date is also effectively 0.0" — this station is at its normal seasonal condition for mid-October. No below-normal language is warranted based on today's reading alone.

For Jerome County context: Lewis Lake Divide monitors Continental Divide snowpack above the upper Snake River, governing inflow to Jackson Lake, then Palisades Reservoir, then American Falls — the supply chain that delivers approximately 80% of Jerome County's irrigation water. The critical 2026 signal is timing: snowpack at this and surrounding stations melted out 4–6 weeks ahead of the historical median meltout date, driven by an anomalous March heat wave. That early meltout shaped this season's reservoir fill trajectory. Meaningful new accumulation at Lewis Lake Divide is not expected until November or later — current conditions are seasonally normal.

Streamflow Conditions

No active USGS streamflow gauges serving Jerome County agricultural water supply are included in this brief's current data set. Jerome County has no in-county Snake River gauges relevant to supply management — the county relies on upstream references at Milner (USGS 13087995) and near Twin Falls (USGS 13090500) as the definitive indicators for North Side Canal delivery conditions. Neither gauge is physically located in Jerome County. Users should contact North Side Canal Company directly for current delivery status and contact IDWR Water District 36 for Snake River operational readings at Milner.

Note: Near-zero Snake River flow below Milner Dam during active irrigation season is normal canal operations — the diversion captures essentially the full river for North Side and Twin Falls Canal deliveries. This is not a supply anomaly.

Seasonal Guidance

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

Data Sources: SNOTEL data through October 11, 2026; USGS streamflow data through October 12, 2026

Data Current As Of: Data sourced from NRCS SNOTEL network and USGS National Water Information System as of dates noted above.

Important Disclaimers: This brief provides automated analysis for informational purposes only. Specific numerical claims have not been independently verified. Consult official sources including: Idaho Department of Water Resources (IDWR, administers Water District 36 — middle Snake River priority system); 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 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 Bear River basin inquiries, contact Idaho Department of Water Resources Eastern Regional Office, Pocatello, (208) 525-7161. This brief does not constitute water rights, legal, or regulatory advice.