Twin Falls County Water Intelligence Brief

October 26, 2026 | Free-Tier Edition

Situation Summary

Snake River flows at Milner Dam are reading zero cfs as of October 26, signaling that the irrigation season diversion has effectively ended and the Twin Falls Canal Company and Northside Canal Company have wound down seasonal deliveries. The Snake River near Twin Falls reads 423 cfs and falling, reflecting post-diversion baseflow conditions as the system transitions fully into the off-season. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All three SNOTEL stations in the Twin Falls County monitoring network are reporting conditions consistent with normal late-October snowpack — none of the stations has yet accumulated meaningful seasonal snowpack.

Lewis Lake Divide (Teton County, WY — 7,880 ft): 0.0" SWE, 0.0" depth as of October 25. The median SWE for this date is also 0.0", meaning the station is at its normal seasonal condition for this point in the calendar. Lewis Lake Divide is the far-upstream Yellowstone-area station that Twin Falls Canal Company irrigators watch most closely — its winter accumulation will govern how much water flows into Jackson Lake and downstream through Palisades and American Falls to Milner by midsummer. Early-season accumulation here has not yet begun, which is unremarkable for late October. Notably, 2026 was an extremely early-melt year: Lewis Lake Divide melted out 4–6 weeks ahead of the historical median meltout date, driven by an anomalous March heat wave — that timing is now background context as the system resets for the 2026–2027 accumulation season.

Magic Mountain: 0.2" SWE, 0.0" snow depth as of October 25. No percent-of-median figure is provided, indicating this reading represents early-season trace accumulation.

Wilson Creek: 0.2" SWE, 0.0" snow depth as of October 25. Similar early trace accumulation; no percent-of-median deviation indicated.

The snowpack story for Twin Falls County water managers now shifts entirely forward — the question is how much snow Lewis Lake Divide and the upper Snake River headwaters accumulate between November and March.

Streamflow Conditions

Snake River at Milner Dam (USGS 13087995): 0 cfs, stable, as of October 26. This is the defining data point for Magic Valley irrigation. A zero reading at Milner confirms that the Twin Falls Canal Company (south bank) and Northside Canal Company (north bank) have completed their seasonal diversions. Milner running at zero in late October is operationally expected as the irrigation season closes.

Snake River near Twin Falls (USGS 13090500): 423 cfs, falling, as of October 26. This gauge monitors 22,360 square miles of upper basin drainage and reflects post-diversion Snake River baseflow below the Milner structure. The falling trend is consistent with seasonal recession as upstream contributions diminish and off-season conditions take hold.

Water managers should note that 423 cfs below Milner in late October, while falling, represents the Snake River running as a river again — during peak irrigation season, the reach below Milner typically runs at near-zero as essentially the entire flow is diverted. The current falling trend bears watching as it will establish the baseline entering winter.

Seasonal Guidance

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Data Sources: SNOTEL data through October 25, 2026; USGS streamflow data through October 26, 2026

Data Current As Of: October 26, 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), Twin Falls Canal Company (primary south-bank diverter at Milner Dam), Northside Canal Company (primary north-bank diverter at Milner Dam), and U.S. Bureau of Reclamation, Pacific Northwest Region (Boise office — for American Falls Reservoir and Palisades Reservoir upstream context) for regulatory decisions and water rights administration.