Mariposa County, CA Noise Ordinances: Construction Hours (2026)

Mariposa County has not adopted a construction-hours ordinance, and there are no codified start or stop times for building, grading or demolition in the unincorporated county. The General Plan Noise Element (Chapter 15) lists construction-noise control only as a future goal: Implementation Measure 15.1a(2) states that 'County development standards shall require means of controlling noise at its source,' and Measure 15.1a(3) states the County 'shall develop and implement standards that will reduce vibration from construction activities to a level that is less than perceptible at adjacent property lines.' The word 'shall develop' signals these were intermediate-term measures, not adopted limits. Because the entire county is unincorporated, the Mariposa County Planning Department administers land-use and building permits, and a specific project may carry conditions of approval that limit work hours on that site even though no countywide hour limit exists. For outdoor public events, the General Plan does authorize project-level conditions on amplification, start and finish times and duration (Measure 15-2b(3)). In the absence of a general construction-hours rule, early-morning or late-night construction that becomes loud and unreasonable can still be addressed under California Penal Code Section 415. Anyone building in communities like Midpines, Bootjack or Mormon Bar should confirm project-specific conditions with the Planning Department.