Off-grid site report
Duval County, TX
27.7631, -98.2353 · 325 ft elevationRead this before you act on anything below. This is my researched starting point for Duval 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 rulesDuval County, TX
Zoning & raw-land occupancy
Generally allowedTexas counties, including Duval County, have no general zoning authority; that power belongs only to cities. No official Duval County zoning ordinance was found, and any zoning would only apply inside San Diego, Benavides, or Freer city limits, not on unincorporated county land.
Dwellings, tiny homes & RVs
Unclear - verifyTexas counties gained narrow authority in 2009 to set some residential construction standards in unincorporated areas, but no official Duval County ordinance adopting such rules or RV occupancy standards was found. Confirm with the Duval County Commissioners Court.
Building permits & codes
Unclear - verifyTexas has no statewide building code and county adoption is optional. No official Duval County building-permit office, adopted code, or portal was located, so this remains unconfirmed either way. source
Septic & composting toilets
Generally allowedSeptic systems (OSSF) are regulated statewide by TCEQ under Texas Health and Safety Code Chapter 366 and 30 TAC Chapter 285. Duval County did not appear on the list of TCEQ-authorized agent counties, so permitting most likely runs through the applicable TCEQ regional office, though this was not directly confirmed. source
Greywater reuse
Unclear - verifyThere is no standalone TCEQ greywater program or confirmed Duval County greywater rule; greywater appears to be handled within the same OSSF framework as septic under 30 TAC 285. source
Rainwater harvesting
Generally allowedRainwater harvesting for domestic use is encouraged at the Texas state level, and no official Duval County restriction or extra permit requirement was found.
Private wells & water rights
Unclear - verifyIt's not confirmed whether Duval County lies within a Groundwater Conservation District; if it does, that district (not the county) sets well-spacing and production rules. Otherwise the state's default rule of capture applies. Check the Texas Water Development Board's GCD directory.
Living disconnected from utilities
Unclear - verifyNo Texas state law requires connecting to utilities, and no official Duval County ordinance on off-grid utility disconnection was found. Any such rule would most likely only exist within San Diego, Benavides, or Freer city limits.
Sun30-year normals
- Peak-sun hours, annual average
- 5.5 hrs/day
- Worst month (sizes an off-grid array)
- 4.3 hrs/day
- Yearly output per 1 kW of panels
- 1,527 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 28 in/yr
- Heating degree days
- 901 (mild)
- Frost-free season
- Jan 31 to Dec 18
How far help isstraight-line
- Hospital
CHRISTUS Spohn Hospital Alice - 11.8 mi
- Fire station
San Diego Fire Department - 0.3 mi
- Hardware store
Sutherlands - 10.9 mi
- Grocery
H-E-B - 10.6 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 78384).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Duval 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.