Off-grid site report
McMullen County, TX
28.4612, -98.5494 · 259 ft elevationRead this before you act on anything below. This is my researched starting point for McMullen County, TX, 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 rulesMcMullen County, TX
Zoning & raw-land occupancy
Generally allowedMcMullen County has no countywide zoning ordinance or zoning department, and there are no incorporated cities in the county to impose municipal zoning. Texas counties generally lack broad zoning power over unincorporated land.
Dwellings, tiny homes & RVs
Unclear - verifyNo county ordinance on minimum dwelling size, tiny homes, or RV living was found on the official county site; not confirmed, ask the county directly.
Building permits & codes
Unclear - verifyThe county's permits page lists permit downloads, but no adopted residential building code (like the IRC) was found referenced by the county; septic is the clearest documented permit type. source
Septic & composting toilets
Generally allowedMcMullen County runs its own OSSF (septic) permitting program under statewide TCEQ rules, with a possible exemption for single-family homes on 10+ acres meeting specific TCEQ conditions. source
Greywater reuse
Unclear - verifyNo county-specific greywater ordinance was found; greywater is generally handled through the same OSSF/septic rules administered by the county rather than a separate permit. source
Rainwater harvesting
Generally allowedNo county ordinance restricting rainwater harvesting was found; it falls under general state-level allowance and standard plumbing practice.
Private wells & water rights
RestrictedAll of McMullen County lies within the McMullen Groundwater Conservation District, created by the Legislature and confirmed by county voters, which sets its own rules for well permitting and groundwater production rather than leaving it to unrestricted rule of capture. source
Living disconnected from utilities
Unclear - verifyNo county ordinance requiring connection to electric, water, or sewer utilities was found, and there are no incorporated cities to impose such a requirement, but this is not fully confirmed, check with the county.
Sun30-year normals
- Peak-sun hours, annual average
- 5.6 hrs/day
- Worst month (sizes an off-grid array)
- 4.4 hrs/day
- Yearly output per 1 kW of panels
- 1,531 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 24 in/yr
- Snowfall
- 0 in/yr
- Heating degree days
- 1,219 (mild)
- Frost-free season
- Feb 16 to Dec 6
How far help isstraight-line
- Hospital
Methodist Hospital South - 32.6 mi
- Fire station
Tilden Volunteer Fire Department - 0.1 mi
- Hardware store
Three Rivers Lumber Yard - 22.2 mi
- Grocery
Lowe's Market - 22.2 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 78072).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in McMullen County, TX?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 21, 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.