Iron County Water Intelligence Brief

Cedar-Parowan Closed Basin | October 19, 2026

*Free-Tier Brief*

Situation Summary

Coal Creek near Cedar City is running at 18 cfs and falling — a signal that the Markagunt Plateau's early-season moisture has largely moved through and late-October recharge contributions will be limited. For Parowan Valley irrigators, the more consequential story remains unchanged: both the Cedar Valley and Parowan Valley aquifers are structurally overdrafted closed-basin systems, and groundwater management plan compliance — not surface water delivery scheduling — is the operational frame that governs your water supply this week and every week. Reservoir storage data and 7-day forecast details are available in the full brief.

Snowpack Conditions

Iron County's SNOTEL network is showing typical mid-October seasonal conditions — most stations are at or near zero snowpack, which reflects normal calendar position rather than below-normal accumulation.

Station readings as of October 18, 2026:

For Iron County's closed-basin hydrology, the Brian Head station at the top of the Markagunt Plateau is the most consequential indicator — it is the primary elevation zone that generates recharge for both Cedar Valley and Parowan Valley aquifers. Brian Head's 0.1" SWE reading represents the season's earliest measurable accumulation rather than residual summer snow. The zero readings at lower-elevation stations are consistent with normal seasonal conditions at this point in October.

As background context: the 2026 water year was defined by an anomalous March heat wave that drove snowmelt across the Markagunt Plateau 4–6 weeks ahead of the historical median meltout date. That early meltout compressed the primary recharge window for both valley aquifers earlier into spring. That story is now historical context — the current question is how the 2026–2027 accumulation season develops from this starting point.

Streamflow Conditions

Coal Creek near Cedar City (USGS 10242000): 18 cfs, falling — October 19, 2026

Coal Creek is the only active USGS streamflow gauge in Iron County, and it should be read as a recharge signal for Cedar Valley, not as an irrigation supply indicator. At 18 cfs and falling, the creek is reflecting late-October baseflow conditions as Markagunt Plateau snowmelt and summer monsoon contributions wind down. This is a small system — Coal Creek's drainage area is approximately 80.9 square miles, and annual average flows are modest by Mountain West standards.

The falling trend is expected at this point in the season. Whether October and November bring early storm recharge events that sustain or briefly spike flows will have marginal bearing on the broader aquifer condition in Cedar Valley, given the chronic structural overdraft that defines the basin.

Parowan Valley monitoring gap: No active USGS gauge exists on Parowan Creek or Center Creek. Parowan Valley surface water conditions cannot be assessed from real-time gauge data. Parowan Valley irrigators should rely on Utah Division of Water Rights reporting and local well monitoring for current supply status — not surface water indicators.

Iron County is a closed basin with no outlet. Water that falls on these mountains stays here or is consumed here — there is no surface water connection to the Sevier River, Virgin River, Colorado River, or any other regional system.

Seasonal Guidance

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Data Sources: SNOTEL data through October 18, 2026; USGS streamflow data through October 19, 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, Cedar City Water Department, and local irrigation companies serving Parowan Valley agricultural users for regulatory decisions and water rights administration.