Off-grid site report
Callahan County, TX
32.3947, -99.3943 · 1,719 ft elevationRead this before you act on anything below. This is my researched starting point for Callahan 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 rulesCallahan County, TX
Zoning & raw-land occupancy
Unclear - verifyTexas counties lack general zoning power over unincorporated land, and no Callahan County zoning ordinance was found. The county does control land division via its Subdivision Regulations, adopted by the Commissioners' Court, but that's platting control, not general zoning. source
Dwellings, tiny homes & RVs
Unclear - verifyNo Callahan County ordinance on dwelling size, tiny homes, or RV occupancy was confirmed; this appears to inherit the state baseline under Texas Local Government Code Chapter 232.
Building permits & codes
Unclear - verifyNo general countywide building code or permit requirement was confirmed beyond the county's subdivision/plat process, which the Callahan County Subdivision Regulations tie to OSSF permit eligibility. source
Septic & composting toilets
Generally allowedSeptic (OSSF) systems are regulated statewide by TCEQ under Texas Health & Safety Code Ch. 366 and 30 TAC Chapter 285, and Callahan County's Subdivision Regulations add plat-review requirements including drainage and groundwater compatibility; the county's Commissioners' Court and OSSF representative review and approve permits locally. source
Greywater reuse
Unclear - verifyNo standalone greywater ordinance or program was found at the county or state level; greywater appears to be handled within the general OSSF framework. Confirm directly with the county's OSSF representative.
Rainwater harvesting
Generally allowedNo Callahan County ordinance restricts rainwater harvesting, and the practice is generally encouraged at the state level in Texas.
Private wells & water rights
Varies locallyIt's not confirmed whether any Groundwater Conservation District covers Callahan County; outside a GCD, Texas defaults to the rule of capture. The county's Subdivision Regulations do require plats to note well locations and proper plugging of unused wells. source
Living disconnected from utilities
Unclear - verifyNo Callahan County ordinance or state law was found requiring connection to electric, water, or sewer utilities for unincorporated land.
Sun30-year normals
- Peak-sun hours, annual average
- 5.9 hrs/day
- Worst month (sizes an off-grid array)
- 4.7 hrs/day
- Yearly output per 1 kW of panels
- 1,656 kWh
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Weather1991-2020
- Precipitation
- 27 in/yr
- Snowfall
- 5 in/yr
- Heating degree days
- 2,676 (mild)
- Frost-free season
- Mar 31 to Nov 8
How far help isstraight-line
- Hospital
Hendrick Medical Center South - 20.4 mi
- Fire station
Baird Volunteer Fire Department - 0.1 mi
- Hardware store
Big Country Hardware - 5.9 mi
- Grocery
United Supermarkets - 5.8 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 79504).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Callahan 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.