Polk County, IA Outdoor Lighting: Billboard Lighting (2026)

Article 11, Division 5 of the Polk County Zoning Ordinance covers sign height, clearance, location and illumination together, and Section 4 sets the county's rule for any lit sign: illuminated signs shall divert glare and keep light from encroaching beyond property boundaries and into the road right-of-way. That single sentence is the operative standard for a billboard's floodlights or internal illumination, since an off-site sign under Article 11, Division 4 is a sign for purposes of this Division too. It sits alongside the Division 4, Section 2(B) requirement that off-site signs meet the Iowa Administrative Code, Transportation Department [761], Chapter 117 Outdoor Advertising rules, which is where more technical billboard-lighting limits (such as any brightness or curfew standards for advertising displays along primary highways) are set at the state level.

The county's own sign-illumination rule reaches beyond billboards to any lit sign, but a billboard's scale, its mounted floodlights or internal LED panel, is exactly the kind of fixture the glare-diversion and boundary-encroachment language targets: light thrown from a 300- to 975-square-foot billboard face has real potential to spill across the property line into a residential lot or into a driver's sightline on the facing road, which is the harm Section 4 is written to prevent.