Colusa County, CA Noise Ordinances: Decibel Limits (2026)

Colusa County's numeric noise standards are in Section 13-6 and Table No. 1 of Chapter 13 (Ord. No. 730). For residential land use, the maximum noise level is 55 dBA from 7 a.m. to 9 p.m. and 50 dBA from 9 p.m. to 7 a.m. For agricultural, commercial, and industrial land use, the limit is 60 dBA from 7 a.m. to 10 p.m. and 55 dBA from 10 p.m. to 7 a.m. A 'high noise traffic corridor' limit of 65 dBA applies anytime, and the table names Highway 20 and Interstate 5 as those corridors. The applicable land use and time period are determined by the affected (complainant's) property's land use under the county general plan, and decibel levels are measured at the complainant's property plane at the point closest to the noise source. Section 13-2 specifies that 'noise level' is measured with a Type S2A-or-better sound level meter on the 'A' weighting scale with the meter response set to 'SLOW.' Section 13-7 establishes an absolute ceiling: no person may produce a noise level more than 20 dBA above the Table No. 1 limit, and in no case greater than 80 dBA, measured at the property plane, regardless of any other exception, except for emergencies and the Section 13-8(a)-(d) activities. These limits apply across unincorporated Colusa County.