Off-grid site report
Alameda County, CA
37.8106, -122.2639 · 36 ft elevationRead this before you act on anything below. This is my researched starting point for Alameda 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 rulesAlameda County, CA
Zoning & raw-land occupancy
RestrictedIn unincorporated Alameda County, Title 17 zoning districts govern what you can do with land, and raw/vacant land occupancy outside an approved use typically needs Site Development Review from the County Planning Department. If you're inside a city like Oakland, Fremont, or Livermore, that city's own planning department controls instead, not the county. source
Dwellings, tiny homes & RVs
RestrictedThe county's zoning code has a dedicated combining RV District, meaning RVs generally aren't allowed as standalone permanent dwellings outside that designation, and tiny homes aren't treated as independent freestanding dwellings either. Accessory units are regulated separately with their own size and occupancy limits, so confirm with the Alameda County Planning Department before trying to live full-time in an RV or tiny home on unincorporated land. source
Building permits & codes
RestrictedAlameda County has adopted its own building ordinance layered on top of the state code, and critically, no county department or city within the county will issue a building permit for a site not connected to public sewer unless an OWTS (septic) Installation Permit has already been issued. That means your building permit and your wastewater plan are tied together from day one, so check with the County's building authority and Department of Environmental Health together. source
Septic & composting toilets
RestrictedThe Alameda County Department of Environmental Health (ACDEH) administers its own OWTS ordinance and an approved Local Agency Management Program covering septic systems, containment units, and portable toilets, with fees set by the Board of Supervisors. If you're in the Tri-Valley/Livermore-Amador area, Zone 7 Water Agency adds its own layer of review on top of ACDEH's; composting toilets specifically aren't spelled out, so ask ACDEH how they'd be handled. source
Greywater reuse
Unclear - verifyI couldn't confirm a county-specific greywater ordinance beyond the state Plumbing Code baseline; the county's stormwater rules cover discharge to storm drains but not greywater reuse directly. Ask the Alameda County Department of Environmental Health how they want greywater systems permitted on your property.
Rainwater harvesting
Generally allowedRainwater harvesting appears to be encouraged as a conservation practice by county-affiliated resources, and I found no county ordinance restricting or specially licensing residential collection, so this seems to just follow the state's generally permissive baseline. Still worth a quick check with the County Planning Department if you're adding large storage tanks or structures.
Private wells & water rights
RestrictedWell permitting in Alameda County is split three ways by geography: Zone 7 Water Agency covers Dublin, Livermore, Pleasanton, and Sunol; Alameda County Water District covers Fremont, Newark, and Union City; and the County's own Public Works Agency handles the rest of unincorporated territory. Zone 7 requires a Drilling Permit Application and sitemap submitted at least ten business days ahead, and the county also requires disclosure of any existing wells on land-use applications, so confirm which agency actually has jurisdiction over your parcel before drilling. source
Living disconnected from utilities
RestrictedThere's no standalone county ordinance specifically banning off-grid electric or water living, but the building permit tie-in to OWTS approval (see building and septic above) means going fully off public sewer still requires county sign-off on your wastewater plan. Confirm specifics with the County's Department of Environmental Health and building authority for unincorporated areas.
Sun30-year normals
- Peak-sun hours, annual average
- 5.7 hrs/day
- Worst month (sizes an off-grid array)
- 3.8 hrs/day
- Yearly output per 1 kW of panels
- 1,595 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 24 in/yr
- Snowfall
- 0 in/yr
- Heating degree days
- 2,363 (mild)
How far help isstraight-line
- Hospital
Menlo Park Surgical Hospital - 24.8 mi
- Fire station
Alameda Fire Station 3 - 2.5 mi
- Hardware store
Pagano's Hardware Store - 3.8 mi
- Grocery
Lakeshore Natural Foods - 1.1 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 94612).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Alameda 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.