Caribou County Water Intelligence Brief

September 14, 2026 | Agricultural Water Supply Summary

Situation Summary

Bear River mainstem flows at Pescadero, ID are running at 1,060 cfs and rising, providing a relatively robust late-season signal for irrigators in Caribou County's primary watershed, though downstream conditions at Corinne, UT have stabilized at 215 cfs and the Blackfoot River above the reservoir remains low at 14 cfs. With the irrigation season in its final weeks, current delivery conditions appear workable, but Blackfoot River basin users should monitor supply closely given the minimal tributary inflow. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

All eight SNOTEL stations serving Caribou County watersheds are reporting at or near zero snow water equivalent (SWE) as of September 13, 2026 — a normal condition for mid-September in this region, as historical median SWE for most stations is also 0.0" at this date.

| Station | SWE | Snow Depth |

|---|---|---|

| Bear River RS | 0.0" | 0.0" |

| Emigrant Summit | 0.2" | 1.0" |

| Franklin Basin | 0.0" | 0.0" |

| Garden City Summit | 0.0" | 0.0" |

| Giveout | 0.4" | 0.0" |

| Slug Creek Divide | 0.0" | 1.0" |

| Tony Grove Lake | 0.0" | 0.0" |

| USU Doc Daniel | 0.0" | 0.0" |

Emigrant Summit (0.2" SWE, 1.0" depth) and Giveout (0.4" SWE) show trace early-season accumulations, while Slug Creek Divide reports 1.0" of snow depth with no measurable SWE — consistent with light, low-density early-fall snow. These readings do not represent meaningful water supply. Background context: the 2026 snowpack melted out 4–6 weeks ahead of the historical median meltout date basin-wide, driven by an anomalous March heat wave — a condition that shaped this season's streamflow timing and is now historical context as the season winds down.

Streamflow Conditions

Bear River Basin

The Bear River at Pescadero, ID is the most relevant mainstem indicator for Caribou County irrigators, currently running at 1,060 cfs on a rising trend — a notably active late-season reading that suggests meaningful reservoir management or upstream inflow contribution. The Bear River at Border, WY (the upstream entry point) shows 51 cfs rising, indicating modest but increasing inflow from the Wyoming headwaters. Downstream at Corinne, UT, the river has stabilized at 215 cfs — the sharp contrast between Pescadero and Corinne reflects intervening diversions, storage operations, and tributary losses through the system.

Tributary gauges in the broader Bear River system show a mixed picture. Blacksmith Fork above the upper and lower canal dam near Hyrum, UT is stable at 48 cfs. Logan River above State Dam near Logan, UT reads 61 cfs, stable. Little Bear River at Paradise, UT is falling at 23 cfs — a typical late-season declining signal. The Malad River near Bear River City, UT shows 6 cfs, though that reading is dated to May 15 and should not be treated as a current condition.

Blackfoot River Basin

The Blackfoot River above the reservoir near Henry, ID reads 14 cfs, stable. This is a low late-season flow consistent with end-of-summer conditions and limited precipitation input. Blackfoot Reservoir operations (Bureau of Reclamation) will govern available supply for basin users more than inflow at this point in the season.

Portneuf River Basin

The Portneuf River at Pocatello, ID reads 43 cfs and is falling — a declining late-season trajectory that irrigators in the Portneuf basin should monitor if deliveries remain active.

Salt River Basin

The Salt River above reservoir near Etna, WY shows 375 cfs, stable — a healthy reading for this point in the season and relevant context for regional water balance, though this gauge is upstream of the Idaho/Wyoming boundary.

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: 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.