Caribou County Water Intelligence Brief

October 5, 2026 | Free-Tier Edition

Situation Summary

Bear River flows through Caribou County are running low and falling, with upper-basin gauges at 42–45 cfs as the irrigation season winds down; water managers should anticipate continued decline through October as upstream snowpack accumulation has not yet begun. The Blackfoot River above the reservoir is holding stable at 20 cfs, offering a modest but steady late-season signal for Blackfoot Reservoir inflows. Reservoir storage data, 7-day forecast details, and delivery reliability analysis for Blackfoot Reservoir and Bear Lake are available in the full brief.

Snowpack Conditions

All monitored SNOTEL stations serving Caribou County's four watersheds are reporting minimal to zero snow water equivalent (SWE) as of October 4, 2026 — a normal condition for this date, as historical median SWE values at these stations are also at or near 0.0" in early October.

Station Readings:

The two stations showing measurable SWE — Emigrant Summit (0.1") and Giveout (0.1") — reflect early-season trace accumulation rather than a meaningful snowpack signal. Franklin Basin's 1.0" snow depth with 0.0" SWE suggests a very light, low-density early dusting. Slug Creek Divide data remains unavailable due to collection issues; users dependent on that station's watershed contribution should contact NRCS directly for status.

Background context: the 2026 water year was marked by an anomalous March heat wave that caused mountain snowpack across the Bear River basin to melt out 4–6 weeks ahead of the historical median meltout date, compressing the spring runoff window and reducing total seasonal water delivery. That event is now well behind the calendar; attention appropriately shifts to accumulation-season monitoring beginning in November.

Streamflow Conditions

Ten USGS gauges spanning Caribou County's four watersheds provide the current streamflow picture. Conditions are broadly low and falling across the Bear River system, consistent with end-of-irrigation-season patterns.

Bear River Basin:

The upper Bear River corridor — from the Wyoming border through Pescadero — is running low and declining, with flows in the 42–45 cfs range. This is a thin margin for any remaining late-season diversion needs. The divergence between upper-basin falling flows and the rising signals at Corinne (475 cfs) and Logan River (96 cfs) warrants attention; rising lower-basin readings may reflect reservoir releases, tributary contributions, or return flow dynamics downstream of Caribou County's primary service area. The Malad River reading is flagged: the 6 cfs figure carries a date of May 15 and should not be treated as current — users relying on that tributary should seek updated data directly from USGS NWIS.

Blackfoot River Basin:

The Blackfoot River is holding steady at 20 cfs above the reservoir — a stable if modest inflow signal heading into the fall storage accumulation period.

Portneuf River Basin:

The Portneuf is falling at 95 cfs. While this gauge is at the downstream Pocatello reference point rather than in Caribou County's core agricultural zone, the falling trend is consistent with system-wide late-season drawdown.

Salt River Basin:

The Salt River is running comparatively robust at 399 cfs and holding stable — a constructive signal for that basin's reservoir inflow and storage outlook heading into the off-season.

Seasonal Guidance

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

Data Sources: SNOTEL data through October 4, 2026; USGS streamflow data through October 5, 2026

Data Current As Of: Idaho Department of Water Resources (Eastern Regional Office in Pocatello, (208) 525-7161, for Bear River basin counties)

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, U.S. Bureau of Reclamation (for Blackfoot Reservoir), and PacifiCorp/Bear River Commission (for Bear Lake storage) for regulatory decisions and water rights administration.