Mariposa County, CA Swimming Pools & Spas: Pool Permits (2026)

Mariposa County is entirely unincorporated, so the County's own Building Department issues all pool and spa permits countywide. Per the County's 'Above-Ground and In-Ground Swimming Pool/Spa Requirements' handout, all swimming pools require a building permit for installation unless specifically exempt under the 2025 California Building Code, Title 24, Part 2, Chapter 1, Section 105.2. The exemptions are narrow: prefabricated pools accessory to a single-family (Group R-3) home that are less than 18 inches deep, hold no more than 5,000 gallons, and are installed entirely above ground need no permit. All other pool and spa work requires a permit. The County requires a drowning-prevention safety device or enclosure approved under California Health & Safety Code sections 115920-115929 and a GFCI-protected electrical system. Submittal documents include a pool/spa information sheet, cover sheet/site plan, pool equipment plan, documentation of at least two required safety features, gas line diagram (if applicable), structural calculations, Title 24 compliance documentation (if heated), the amount of soil to be moved, and erosion-control Best Management Practices. Environmental Health also has requirements that must be met. Contact Building at 209-966-3934.