Off-grid site report
Calhoun County, TX
28.6333, -96.6284 · 30 ft elevationRead this before you act on anything below. This is my researched starting point for Calhoun 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 rulesCalhoun County, TX
Zoning & raw-land occupancy
Varies locallyCalhoun County has no countywide zoning ordinance; land use in unincorporated areas is controlled instead through Floodplain Administration, Subdivision Regulations, RV Park Regulations, and Mobile Home Park Regulations. Incorporated towns like Port Lavaca may impose their own zoning within limits/ETJ, not covered here.
Dwellings, tiny homes & RVs
Varies locallyPermanent dwellings on platted land follow county subdivision rules, while parks follow separate RV Park or Mobile Home Park Regulations; whether standalone tiny homes on raw land face a minimum size rule is not confirmed, so check with the Floodplain Administrator.
Building permits & codes
Varies locallyThe county requires a development permit with flood-resistant construction and elevation above Base Flood Elevation for flood-hazard areas; separately, the state's windstorm zone map puts Calhoun County under 2006 IBC/IRC with Texas Revisions at 120 mph design wind speed for windstorm insurance purposes. No general countywide building code adoption was confirmed beyond these. source
Septic & composting toilets
Generally allowedCalhoun County administers OSSF (septic/holding tank) permitting as TCEQ's authorized local agent; a 10-acre exemption may apply under state rules if specific conditions are met. Aerobic treatment units are typical locally due to soil conditions. source
Greywater reuse
Unclear - verifyNo standalone Calhoun County greywater rule was found; greywater appears to be handled within the standard OSSF permitting process under state (TCEQ) rules. Confirm with the county's OSSF/Environmental Health office whether a simplified permit exists. source
Rainwater harvesting
Generally allowedNo Calhoun County restriction on rainwater harvesting was found, and Texas state water policy (TWDB) affirmatively encourages it, so the state baseline applies.
Private wells & water rights
RestrictedThe Calhoun County Groundwater Conservation District no longer requires a drilling permit for water wells, but written notice of intent must be given to the district before drilling; larger or transfer uses still need production/transfer permits. source
Living disconnected from utilities
Unclear - verifyNo Calhoun County ordinance requiring connection to electric, water, or sewer utilities in unincorporated areas was found; any such requirement would come from an incorporated town like Port Lavaca and was not researched here.
Sun30-year normals
- Peak-sun hours, annual average
- 5.3 hrs/day
- Worst month (sizes an off-grid array)
- 3.9 hrs/day
- Yearly output per 1 kW of panels
- 1,474 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 43 in/yr
- Heating degree days
- 1,125 (mild)
How far help isstraight-line
- Hospital
Memorial Medical Center - 0.9 mi
- Fire station
Port Lavaca FIre Department - 0.3 mi
- Hardware store
Ace Hardware - 0.8 mi
- Grocery
Walmart Supercenter - 0.1 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 77979).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Calhoun 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.