Summit County, UT Environmental Rules: Flood Zones (2026)

Floodplain regulation in unincorporated Summit County is governed by Title 12 (Flood Control) of the Summit County Code. Title 12 Chapter 2 establishes the general provisions and statement of compliance: under Section 12-2-3, no structure or land may be constructed, located, extended, converted, or altered without full compliance with the terms of Title 12 and other applicable regulations, and a Floodplain Development Permit must be obtained before any construction or development begins within any Area of Special Flood Hazard established by the FEMA Flood Insurance Study and accompanying FIRMs adopted in Section 12-2-2. Title 12 Chapter 3 (Administration) sets out the framework for the Floodplain Administrator and permitting process, including Section 12-3-1 (Designation of Administrator), Section 12-3-2 (Floodplain Development Permit), Section 12-3-3 (Duties and Responsibilities of Administrator), Section 12-3-4 (Permit Procedures), and Section 12-3-5 (Appeal and Variance Procedures). Under Section 12-3-2, applications for a Floodplain Development Permit must include a site plan drawn to scale showing location, dimensions, and elevation of proposed alterations, existing and proposed structures, and the location in relation to areas of special flood hazard, including horizontal boundaries and base flood elevation. Applicants must provide base flood elevation data for the proposed development area, the elevation in relation to mean sea level of the lowest floor (including basement) of all structures, the elevation to which any structure has been or will be floodproofed, and certification by a licensed professional engineer or architect that floodproofing methods used for any nonresidential structure meet the floodproofing criteria of Title 12. Approval or denial of a permit is based on factors including the danger to life and property due to flooding or erosion damage, the susceptibility of the proposed facility and its contents to flood damage, the danger that materials may be swept onto other lands, the compatibility of the proposed use with existing development, and the safety of access to the property in times of flood for ordinary and emergency vehicles. Summit County is a participating community in the National Flood Insurance Program; Special Flood Hazard Areas in the unincorporated county and incorporated municipalities (Coalville, Francis, Henefer, Kamas, Oakley, Park City) are mapped by FEMA on the effective FIRM panels available at the FEMA Map Service Center (msc.fema.gov). Major flood sources in Summit County include the Weber River and its tributaries flowing west toward the Wasatch Front, the headwaters of the Provo River draining the south slope of the Uinta Mountains, and Chalk Creek, Silver Creek, and other mountain streams subject to spring snowmelt and high-elevation runoff. The Utah Division of Emergency Management's Floodplain Mapping Program (the Cooperating Technical Partner with FEMA) maintains state-level mapping resources at floodhazards.utah.gov, and the Utah Geospatial Resource Center publishes flood-area data at gis.utah.gov. Property owners who believe a structure is mistakenly mapped within an SFHA may apply to FEMA for a Letter of Map Amendment (LOMA) or Letter of Map Revision (LOMR). Sandbags and emergency flood response in unincorporated areas are coordinated by Summit County Public Works at (435) 336-3200; residents inside Coalville, Francis, Henefer, Kamas, Oakley, or Park City should contact their respective city public works departments.