Caribou County, ID — Agricultural Water Intelligence Brief

June 1, 2026

Situation Summary

Caribou County enters June 2026 in a critically stressed water supply position. Snowpack across the Bear River and surrounding basins has essentially vanished, with nearly all SNOTEL monitoring stations reporting zero snow water equivalent as of May 31. The 2026 season has been characterized as one of the worst snow years on record in the Mountain West, and that characterization is borne out by local data. While several streamflow gauges are currently recording moderate to stable flows, those readings reflect residual runoff rather than ongoing snowmelt contributions of any significance. Agricultural water users across all four watersheds serving Caribou County — Bear River, Blackfoot River, Portneuf River, and Salt River — should anticipate a difficult summer and begin active supply management now.

Snowpack Conditions

The snowpack picture across Caribou County's contributing watersheds is, in nearly every respect, exhausted. Of the eight SNOTEL stations monitored in the region, six are reporting 0.0 inches of snow water equivalent (SWE) and 0.0 inches of snow depth as of May 31: Bear River RS, Emigrant Summit, Garden City Summit, Giveout, Slug Creek Divide, and Tony Grove Lake. Tony Grove Lake, which carries a normal June 1 median of 6.6 inches SWE, is at 0% of median — a stark indicator of how far below normal conditions have fallen.

Two stations retain trace amounts. Franklin Basin is reporting 0.6 inches SWE with 2.0 inches of depth, and USU Doc Daniel is reporting 0.9 inches SWE (5% of its 16.4-inch median) with 4.0 inches of depth. These remnant readings represent negligible contributions to seasonal water supply and should not be interpreted as a meaningful snowmelt buffer going forward.

In practical terms: the seasonal snowpack contribution to summer streamflow and reservoir replenishment is, for all purposes, complete. Water supply for the remainder of the 2026 irrigation season will depend almost entirely on existing reservoir storage, groundwater, and whatever precipitation events may occur.

Streamflow Conditions

Current streamflow readings across the basin present a mixed picture that warrants careful interpretation. Several gauges are recording flows that may appear adequate in isolation but should be viewed in the context of a depleted snowpack and advancing season.

Within the Bear River Basin, the Bear River at Pescadero, ID — the gauge most directly relevant to Caribou County diversions — is recording 910 cfs (stable) as of June 1. The Bear River at Border, WY is reading 255 cfs (rising), and Bear River near Corinne, UT is at 780 cfs (rising). The Logan River above State Dam is at 342 cfs (rising), Blacksmith Fork is at 67 cfs (stable), Little Bear River at Paradise is at 40 cfs (rising), and the Malad River near Bear River City is at 6 cfs (most recent data from May 15).

In the Blackfoot River Basin, flows above the reservoir near Henry, ID are at 105 cfs (rising). The Portneuf River at Pocatello is recording 76 cfs (rising). The Salt River above reservoir near Etna, WY is at 496 cfs (stable).

The rising trend on several gauges may reflect recent precipitation or localized late-season drainage rather than sustained snowmelt. With snowpack effectively gone at nearly all stations, users should not plan on these flows being maintained through peak demand months. Streamflow declines during July and August are a foreseeable outcome under current conditions.

Key Reservoir Systems

Caribou County's agricultural water supply depends on several reservoir systems that serve as the primary buffer against low-snowpack years:

Current storage figures are not included in this brief. Users are strongly encouraged to contact the U.S. Bureau of Reclamation for Blackfoot Reservoir status and PacifiCorp/Bear River Commission for Bear Lake storage data before making supply assumptions. In a low-snowpack year, carry-in storage levels are especially consequential and should be verified directly.

Water Rights Administration Outlook

Caribou County users operate under Idaho's prior appropriation doctrine, administered by the Idaho Department of Water Resources (IDWR). Given the near-total absence of snowpack and the likelihood of declining streamflows through the summer, there is a high likelihood of water rights curtailments affecting junior priority holders across one or more of the county's watersheds.

Bear River compact administration adds a layer of complexity, as interstate obligations may influence how available flows are distributed among Idaho users. Users with junior priority dates — particularly those holding rights from the 20th century — should assess their exposure now rather than waiting for formal curtailment notices.

Users are encouraged to contact the IDWR Eastern Regional Office in Pocatello (208-525-7161) for current administration status and to review their priority dates relative to likely call conditions. Canal companies and irrigation districts should communicate proactively with their membership about the potential for reduced or interrupted deliveries.

Groundwater Considerations

Groundwater users in Caribou County operate primarily within the Bear River Groundwater Management Area (Bear River GWMA), designated in 2001 by IDWR and covering Bear Lake, Caribou, and Franklin counties. The relevant aquifer is the Bear River Valley alluvial aquifer. Users in eastern and northern portions of the county, particularly near Soda Springs, may have some connection to Snake River basin aquifer systems, though Bear River valley floor users are primarily within the Bear River GWMA.

In dry surface water years, pressure on groundwater typically increases as irrigators seek supplemental supply. Users considering increased groundwater pumping should verify their water rights authorize such use and consult IDWR regarding any applicable management area rules before expanding pumping. Increased withdrawals from a stressed system can affect neighboring users and may be subject to administration.

Management Recommendations

Immediate Actions (Now through mid-June):

Planning Actions (June–July):

Efficiency Actions (Ongoing):

Historical Context

The 2026 season bears resemblance to several historically difficult water years in the Mountain West. The 2021 drought brought significant curtailments across Idaho and adjacent states, with many irrigation districts implementing prorated deliveries and some users receiving only a fraction of their normal allotments. The 2015 drought similarly triggered emergency measures across the region, including voluntary and mandatory reductions in groundwater pumping and canal deliveries. The 1977 drought — still referenced as a benchmark low-water year — required widespread agricultural adjustments, with some operations unable to sustain normal production levels.

Each of those years underscored that early planning and proactive communication with water managers produced better outcomes than reactive responses. The current snowpack data suggests 2026 may belong in this same category of difficult years.

Data Sources

NRCS SNOTEL network (8 stations), USGS National Water Information System (10 gauges), National Weather Service seasonal outlooks

Data Current As Of

SNOTEL data through May 31, 2026; USGS streamflow data through June 1, 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 (Eastern Regional Office in Pocatello, (208) 525-7161, for Bear River basin counties), U.S. Bureau of Reclamation (for Blackfoot Reservoir), and PacifiCorp/Bear River Commission (for Bear Lake storage) for regulatory decisions and water rights administration.

*Next recommended update: June 8, 2026 | Prepared for Caribou County agricultural users*