Washoe County, NV Environmental Rules: Flood Zones (2026)

Washoe County adopts its building code amendments in Code Chapter 100, and several provisions apply specifically to construction within FEMA-mapped special flood hazard areas. 3, the county requires that, in special flood hazard areas, the elevations of the bottom floor (including any crawl space or basement), the next higher floor, the attached garage floor, the lowest machinery or equipment serving the building, and the lowest and highest adjacent grades be certified by a licensed engineer or land surveyor on a FEMA Elevation Certification; that certification must go to the County Engineer for review and approval before the building official will conduct the final inspection.

2, the site plan accompanying a building-permit application must show, as applicable, flood hazard areas, floodways, and design flood elevations, drawn to an accurate boundary-line survey, alongside lot lines and finished grades. 3 of the International Existing Building Code, even where other alteration work could otherwise rely on the code in effect when the building was built. Together these sections mean a property owner building, adding onto, or substantially repairing a structure in a mapped flood hazard area cannot get a final inspection signed off without a surveyor-certified elevation on file with the County Engineer, and cannot get the permit issued without the site plan disclosing the flood hazard area and design flood elevation.