Off-grid site report
Tuolumne County, CA
37.9613, -120.2390 · 2,579 ft elevationRead this before you act on anything below. This is my researched starting point for Tuolumne County, CA, not legal advice and not a guarantee. Rules change, and the deciding facts on any specific parcel (setbacks, perc results, overlay districts, deed restrictions, road frontage) live at the county or town office, not in any database. Before you buy land or build, confirm the current rules directly with the local zoning and health offices - the sources on this page tell you exactly who to call.
The local rulesTuolumne County, CA
Zoning & raw-land occupancy
RestrictedTuolumne County's countywide Zoning Ordinance (Title 17) covers all unincorporated land; raw-land occupancy without an approved dwelling is enforced as a violation. Some ag/resource districts like AE-160 permit low-density rural dwellings under acreage minimums. source
Dwellings, tiny homes & RVs
RestrictedThe county treats RV living beyond 30 days as a code violation; tiny homes are classified per state HCD rules and then must meet county zoning/building rules; ADUs are permitted under a dedicated county ADU chapter plus state law. source
Building permits & codes
RestrictedTuolumne County's Building and Safety Division reviews and inspects nearly all construction in unincorporated areas, and building without a permit is actively enforced; a pre-approved plan program exists for ADUs and single-family homes. source
Septic & composting toilets
RestrictedEnvironmental Health permits septic systems under a state-approved Local Agency Management Program requiring a soil/site feasibility study; composting toilets as a standalone system are not clearly addressed, so ask Environmental Health directly. source
Greywater reuse
Generally allowedNo Tuolumne-specific greywater ordinance was found; the statewide California Plumbing Code Chapter 15 baseline appears to apply as administered locally by Building/Environmental Health. Not confirmed whether stricter local rules exist. source
Rainwater harvesting
Generally allowedNo county-specific rainwater ordinance was located; assume the state Water Code baseline applies with no added county permit for simple rooftop catchment, though this is not explicitly confirmed.
Private wells & water rights
RestrictedEnvironmental Health, under its Local Enforcement Agency program, permits siting, construction, and water quality testing for new wells, with fees set in the county's Environmental Health fee schedule. source
Living disconnected from utilities
RestrictedNo ordinance names off-grid living directly, but permit, septic/well, and RV-occupancy rules together mean year-round occupancy generally requires a permitted dwelling with approved water and wastewater systems; solar-only electric setups are not specifically addressed, so confirm with Building and Safety. source
Sun30-year normals
- Peak-sun hours, annual average
- 5.9 hrs/day
- Worst month (sizes an off-grid array)
- 4.0 hrs/day
- Yearly output per 1 kW of panels
- 1,611 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 35 in/yr
- Heating degree days
- 3,719 (moderate)
- Frost-free season
- Apr 18 to Nov 6
How far help isstraight-line
- Hospital
Adventist Health Sonora - 7.3 mi
- Fire station
Tuolumne City Fire Department - 0.0 mi
- Hardware store
Kolpack Construction - 3.0 mi
- Grocery
Twain Harte Market - 5.5 mi
From OpenStreetMap. Road miles will be longer, often much longer in hill country.
Plan this spot
These open with this location's real numbers already filled in (ZIP 95379).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Tuolumne County, CA?The rules above are the jurisdiction. The land check runs the parcel itself: flood zone, soils and septic suitability, wetlands, slope, access, climate, and these verdicts, from a parcel number or coordinates.
Check a parcel →Share or save this report:New report
Sources: US Census Bureau geocoder; NLR PVWatts v8 (solar); NOAA NCEI 1991-2020 climate normals (nearest station) or Open-Meteo (ZIP-centroid) for weather; Open-Elevation; OpenStreetMap contributors. Public data retrieved Aug 22, 2026; agencies update their layers on their own schedules. Planning data, not a survey or legal advice.
New here, or not sure where this fits? Start here walks through the whole thing in order.