Off-grid site report
Galveston County, TX
29.4041, -95.0364 · 30 ft elevationRead this before you act on anything below. This is my researched starting point for Galveston 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 rulesGalveston County, TX
Zoning & raw-land occupancy
Varies locallyUnincorporated Galveston County has no general zoning code; land use is mainly controlled through county floodplain/engineering permitting. Cities within the county, like Galveston, run their own separate zoning ordinances. source
Dwellings, tiny homes & RVs
Unclear - verifyThe county has a defined process for RV/mobile-home parks in unincorporated areas, but placing a single RV or tiny home as a standalone residence isn't addressed in any county ordinance I found, so confirm with the county engineering office. Inside city limits, municipal permitting applies. source
Building permits & codes
Varies locallyUnincorporated county areas have adopted parts of the International Residential Code but there's no general countywide building-permit department; cities like Galveston run full permitting and Certificate of Occupancy programs. source
Septic & composting toilets
Generally allowedThe Galveston County Health District, acting as the state's authorized agent, issues OSSF permits, requires an approved plan before construction, and inspects installed systems. source
Greywater reuse
Unclear - verifyNo standalone greywater ordinance or permit is listed by Galveston County; it appears folded into the general OSSF/septic permitting framework, which is really a state-level baseline. Ask GCHD to confirm.
Rainwater harvesting
Generally allowedNo Galveston County restriction was found; rainwater harvesting is governed by state law rather than a county-specific rule. source
Private wells & water rights
RestrictedGalveston County lies within the Harris-Galveston Subsidence District, a state-created special district that requires a well permit application for each well, a stricter regime than simple rule-of-capture. source
Living disconnected from utilities
Generally allowedThe county states that its floodplain permit issuance does not guarantee or require utility availability, suggesting unincorporated land can be developed off-grid; city rules within municipal limits may differ. source
Sun30-year normals
- Peak-sun hours, annual average
- 5.1 hrs/day
- Worst month (sizes an off-grid array)
- 4.0 hrs/day
- Yearly output per 1 kW of panels
- 1,438 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 57 in/yr
- Snowfall
- 0 in/yr
- Heating degree days
- 1,400 (mild)
- Frost-free season
- Feb 12 to Dec 9
How far help isstraight-line
- Hospital
Houston Methodist Saint John Hospital - 10.5 mi
- Fire station
Texas City Fire Department Station 3 - 2.2 mi
- Hardware store
The Home Depot - 5.1 mi
- Grocery
SK Quick Mart - Citgo - 3.9 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 77510).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Galveston 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.