Iron County Water Intelligence Brief

August 17, 2026 | Cedar-Parowan Closed Basin

Situation Summary

Iron County's water story is fundamentally a closed-basin groundwater story: Cedar Valley and Parowan Valley are internally draining basins with no surface outlet, and both aquifers have been pumped beyond sustainable recharge for decades — a structural condition that no single wet season can reverse. The 2026 snowpack on the Markagunt Plateau melted out 4–6 weeks ahead of the historical median meltout date, compressing the natural recharge window that feeds both valley aquifers. Reservoir storage data and detailed operational recommendations are available in the full brief.

Snowpack Conditions

All six SNOTEL stations monitoring Iron County's Markagunt Plateau and surrounding uplands are reporting at fully melted-out conditions as of August 16, 2026 — which is normal for mid-August at these elevations. However, the critical 2026 context is timing: snowpack at these stations melted out 4–6 weeks ahead of the historical median meltout date, meaning the natural recharge season delivered its pulse to Cedar Valley and Parowan Valley aquifers significantly earlier in the calendar year than typical.

Station readings (August 16, 2026):

Brian Head SNOTEL is the primary recharge signal for both valleys — at 10,040 feet, it captures the high-elevation Markagunt snowpack that drives seasonal infiltration into the aquifer systems below. The trace residual depth at Brian Head and the 0.1" SWE reading at Castle Valley are not operationally meaningful at this point in August. What matters for Parowan Valley irrigators and Cedar City water managers is that the recharge contribution from this season's snowpack was delivered earlier than normal, and no further snowmelt recharge is expected until the next accumulation season.

Streamflow Conditions

Coal Creek Near Cedar City (USGS 10242000): 9 cfs — stable (August 16, 2026)

Coal Creek is Iron County's only active USGS streamflow gauge. At 9 cfs, the creek is running at a late-summer baseflow level consistent with the post-meltout period. This reading should be understood as a recharge signal, not an irrigation supply volume — Iron County agriculture is groundwater-dependent, and Coal Creek at this scale (draining approximately 80.9 square miles of Markagunt Plateau) does not represent a meaningful direct supply source for Parowan Valley alfalfa and hay operations.

For Cedar Valley, Coal Creek's baseflow at this level reflects the tail end of seasonal discharge from the Markagunt Plateau. The creek's annual contribution — roughly 24,200 acre-feet in average years — is small by Mountain West standards and terminates in a dry lake/playa rather than connecting to any larger river system. Iron County is a closed basin: snowmelt that falls on these mountains stays here or is consumed here.

A critical monitoring gap exists for Parowan Valley: no active USGS gauge operates on Parowan Creek or Center Creek. Conditions in the primary agricultural valley cannot be assessed through public streamflow data. Parowan Valley irrigators must rely on groundwater management plan reporting, local well monitoring, and direct contact with the Utah Division of Water Rights for current aquifer status.

Seasonal Guidance

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

Data Sources: SNOTEL data through August 16, 2026; USGS streamflow data through August 17, 2026

Data Current As Of: Utah Division of Water Rights

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, Utah Division of Water Rights (State Engineer — issues and administers groundwater management plans for Cedar Valley and Parowan Valley aquifers; the governing documents for long-term aquifer protection; waterrights.utah.gov), Iron County Water Conservancy District (local water authority), Cedar City Water Department (primary municipal water provider for Cedar City area), and local irrigation companies serving Parowan Valley agricultural users for regulatory decisions and water rights administration.