Waterloo, IA Noise Ordinances: Decibel Limits (2026)

Table II in § 4-5-3 sets the city's core numeric noise ceiling, splitting the day (7:00 A.M. to 11:00 P.M.) from the night (11:00 P.M. to 7:00 A.M.) across three zones: residential is capped at 80 dBA by day and 55 dBA at night, commercial at 80 dBA by day and 60 dBA at night, and industrial at 82 dBA by day and 75 dBA at night. The code states plainly that any noise above those dBA figures is a violation, and measurements are taken at the nearest lot line, but never less than twenty-five feet from the noise source.

A separate Table I sets vehicle noise limits by class and speed: 86 dBA at 45 mph or less, rising to 90 dBA above 45 mph, for interstate and other trucks over 10,000 pounds GCWR; 80 dBA and 84 dBA for motorcycles; and 74 dBA and 80 dBA for all other vehicles, measured at least twenty-five feet from the curb and one hundred feet from any intersection. Section 4-5-4 then cross-references Table II throughout its list of specifically prohibited noise sources, from amplified sound and loudspeakers to construction equipment and power tools, so the zone-and-time limits in Table II function as the baseline every other noise provision in the chapter measures against. The city council may also designate a noise-sensitive zone with its own, stricter decibel limits under § 4-5-4(N).