Twin Falls County Water Intelligence Brief

September 14, 2026 | Free-Tier Edition

Situation Summary

Snake River flows at Milner Dam are reading 0 cfs as of September 14, with essentially all available Snake River water diverted into the Twin Falls and Northside canal systems — a condition typical of peak late-season irrigation demand, but one that leaves no buffer for supply shortfalls from the upper basin. At 517 cfs near Twin Falls, residual flows below the diversion reflect return flows and spring contributions rather than a meaningful upstream delivery reserve. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All three monitored SNOTEL stations in the Twin Falls County upstream network are reporting at their expected seasonal baseline for mid-September:

At this point in the calendar, 0.0" SWE across these stations reflects normal seasonal meltout — the median SWE for mid-September at these elevations is also effectively zero, so current readings do not indicate a below-normal condition for today's date. The relevant upstream signal for 2026 is timing: Lewis Lake Divide and companion stations melted out approximately 4–6 weeks ahead of the historical median meltout date, meaning the peak runoff pulse that fills American Falls Reservoir and drives Snake River flows through Milner arrived and passed earlier in the season than typical.

Streamflow Conditions

Two USGS gauges define the operational picture for Twin Falls County irrigators:

The Milner gauge reading of 0 cfs confirms that Twin Falls Canal Company and Northside Canal Company diversions are capturing the full Snake River flow at the diversion dam — the defining hydrology of Magic Valley in irrigation season. This is not an anomaly; during active irrigation season the Snake River below Milner routinely runs at near-zero as essentially the entire flow is directed into approximately 202,000 acres of canal-served farmland. The 517 cfs measured near Twin Falls downstream reflects spring discharge, irrigation return flows, and ESPA contributions entering the river below the diversion — not Snake River mainstem supply. For upstream storage context governing what arrives at Milner in coming weeks, contact IDWR Water District 36 or USBR Pacific Northwest Region for current American Falls and Palisades Reservoir status.

Seasonal Guidance

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

Data Sources: SNOTEL data through September 13, 2026; USGS streamflow data through September 14, 2026

Data Current As Of: September 14, 2026

Important Disclaimers: This brief provides automated analysis for informational purposes only. Specific numerical claims have not been independently verified. Consult official sources including Twin Falls Canal Company (primary south-bank diverter at Milner Dam), Northside Canal Company (north-bank diverter), IDWR Water District 36 watermaster (middle Snake River priority administration), and USBR Pacific Northwest Region (Boise office) for American Falls Reservoir and Palisades Reservoir operational status. This brief does not constitute water rights or legal advice.