Off-grid site report
Karnes County, TX
28.8851, -97.9012 · 436 ft elevationRead this before you act on anything below. This is my researched starting point for Karnes 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 rulesKarnes County, TX
Zoning & raw-land occupancy
Varies locallyKarnes County has no general zoning power over unincorporated land, but its subdivision rules require floodplain, driveway, and septic permits before occupancy. Incorporated towns like Karnes City or Kenedy may zone within their limits and ETJ, so check locally if near a town. source
Dwellings, tiny homes & RVs
Unclear - verifyNo specific county ordinance on minimum dwelling size or RV occupancy was found; confirm directly with the county's Special Projects/Development office. source
Building permits & codes
Varies locallyUnincorporated county requires a Determination Development Permit before OSSF application, but no general countywide building code was confirmed. Karnes City has its own building permit system through the Building Officials office at City Hall. source
Septic & composting toilets
Generally allowedKarnes County issues OSSF permits under state TCEQ rules, requiring a Development Permit first; aerobic systems need maintenance contracts and the permit transfers with property sale. A statewide 10-acre exemption may apply in some cases but confirm with the county. source
Greywater reuse
Unclear - verifyNo standalone Karnes County greywater ordinance was found; it's presumably addressed within the state's general OSSF rules (30 TAC 285). Not confirmed at the county level.
Rainwater harvesting
Generally allowedRainwater harvesting is permitted and actively promoted by the Evergreen Underground Water Conservation District, which covers Karnes County, through public education programs. No added county permit requirement was found.
Private wells & water rights
Varies locallyKarnes County lies within the Evergreen Underground Water Conservation District, so local well rules and possible permitting apply rather than pure rule-of-capture; the district is actively studying well-spacing policy for the county's aquifer.
Living disconnected from utilities
Unclear - verifyNo countywide utility-connection mandate was found for unincorporated areas; within Karnes City limits, a utility service availability review appears to be part of the building permit process. source
Sun30-year normals
- Peak-sun hours, annual average
- 5.5 hrs/day
- Worst month (sizes an off-grid array)
- 4.2 hrs/day
- Yearly output per 1 kW of panels
- 1,509 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 30 in/yr
- Snowfall
- 0 in/yr
- Heating degree days
- 1,373 (mild)
- Frost-free season
- Feb 24 to Dec 5
How far help isstraight-line
- Hospital
Otto Kaiser Memorial Hospital - 2.8 mi
- Fire station
Karnes City Volunteer Fire Department - 0.2 mi
- Hardware store
- none within range
- Grocery
Walmart Supercenter - 4.1 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 78118).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Karnes 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.