Provo, UT Environmental Rules: Flood Zones (2026)

180 implements the National Flood Insurance Act of 1968 and requires a floodplain development permit before construction or development begins anywhere within a special flood hazard area (SFHA) mapped on the FIRM. Applications must show the elevation, relative to mean sea level, of the lowest floor (including basement) of every proposed structure, and plans must demonstrate that floor is at least one foot above the base flood elevation (BFE), Provo's local freeboard standard. Depending on whether the project would alter floodplain delineations, the Floodplain Administrator can require a Conditional Letter of Map Revision (CLOMR) or CLOMR-F submitted to FEMA before the permit issues, followed by a LOMR or LOMR-F to close out the process.

Nonresidential structures may instead be dry-floodproofed below the BFE if a registered engineer or architect certifies the design resists hydrostatic and hydrodynamic loads; a building later converted to residential use cannot rely on that floodproofing and must be retrofitted to residential standards. Within designated regulatory floodways, encroachments including fill and new construction are prohibited unless a registered professional engineer certifies, via a no-rise analysis, that the work will not raise the base flood elevation. Manufactured homes in Zones A1-30, AH, AE, V, VE and V1-30 must be elevated on a permanent foundation with the lowest floor one foot above the BFE and anchored against flotation and lateral movement.

Enclosed crawlspaces and under-floor areas need flood vents sized at one square inch per square foot of enclosed area, with vent bottoms no more than one foot above grade. Subdivisions and manufactured home parks exceeding fifty lots or five acres must generate BFE data where none exists.