West Des Moines, IA Noise Ordinances: Decibel Limits (2026)

Section 4-7-7 of the Noise Control Regulations sets the maximum permissible sound level allowed at or within the property boundary of a receiving land use, separately for unamplified and amplified sound, unless another part of the chapter authorizes something different. For unamplified sound measured as L5A, subsection A caps residential and noise-sensitive land uses at 65 dBA from seven A.M. to seven P.M., 60 dBA from seven P.M. to ten P.M., and 55 dBA from ten P.M. to seven A.M.; commercial land uses stay flat at 65 dBA around the clock, and industrial land uses are allowed up to 80 dBA at all hours.

For amplified sound measured as L5C, subsection B sets residential and noise-sensitive limits of 76 dBC by day, 74 dBC in the evening, and 72 dBC overnight, with commercial capped at 82, 80, and 78 dBC across the same three periods and industrial fixed at 85 dBC around the clock. Subsection C makes any reading that exceeds these limits during a ten-minute meter reading a violation of the chapter. Section 4-7-10 backs this up with a general prohibition: no person may engage in activity producing noise above the section 4-7-7 limits, and property owners, lessees, and event organizers each have a duty to prevent activity on their premises or by their group from exceeding them.

Section 4-7-16 singles out this section for treatment as a municipal infraction only, rather than a criminal misdemeanor, and section 4-7-8 lists activities, such as emergency vehicles and permitted construction hours, that are exempt from these numeric caps.