Off-grid site report

Grimes County, TX

30.4887, -95.9870 · 377 ft elevation

Read this before you act on anything below. This is my researched starting point for Grimes 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 rulesGrimes County, TX

Zoning & raw-land occupancy

Generally allowedGrimes County has no countywide use-based zoning ordinance for unincorporated land; the county instead regulates subdivision platting under Texas Local Government Code Chapters 232/233. Incorporated towns like Navasota may have their own separate zoning. source

Dwellings, tiny homes & RVs

Varies locallyThe county adopted the 2021 International Residential Code for new residential construction starting December 2024, using a notice-based process rather than full county inspection. No specific policy on tiny homes or RVs as permanent dwellings was found; confirm with the Development Coordinator. source

Building permits & codes

Varies locallyNew residential construction must meet IRC 2021 as adopted by Grimes County Commissioners Court; builders submit Notice of Construction and Notice of Inspection since the county does not inspect structures itself. A separate Infrastructure Regulations order (2025) covers commercial/subdivision development. source

Septic & composting toilets

Generally allowedGrimes County's Environmental Department issues OSSF permits as TCEQ's authorized local agent under 30 TAC Chapter 285. A statewide exemption ('10-acre rule') may apply for a single-family home on 10+ acres meeting setback and site conditions; confirm eligibility with the county. source

Greywater reuse

Unclear - verifyNo standalone Grimes County or state greywater rule was found separate from septic regulation; likely governed under the same OSSF/30 TAC 285 framework, but this is not confirmed. Ask the Environmental Department directly.

Rainwater harvesting

Generally allowedNo Grimes County ordinance restricts rainwater harvesting, and Texas generally takes a permissive approach to it at the state level.

Private wells & water rights

RestrictedGrimes County falls under the Bluebonnet Groundwater Conservation District (covering Grimes, Washington, Waller, and Austin counties), which regulates well registration, spacing, and permitting for non-exempt wells rather than leaving it to pure rule-of-capture. source

Living disconnected from utilities

Unclear - verifyNo county or state mandate requiring connection to electric, water, or sewer utilities for an existing unincorporated residence was found; subdivision infrastructure rules mainly target new development. Confirm with the Development Coordinator if your situation involves platting. source

Open the full county page with sources →

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: 1,460 kWh

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Weather1991-2020

Precipitation: 42 in/yr
Snowfall: 0 in/yr
Heating degree days: 1,878 (mild)
Frost-free season: Mar 14 to Nov 19

How far help isstraight-line

Hospital CHI Saint Joseph Health Grimes Hospital: 8.6 mi
Fire station Anderson Fire Department: 0.4 mi
Hardware store Anderson Auto & Hardware: 0.1 mi
Grocery Arlan's Market: 8.5 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 77830).

Size a solar system Heat loss & insulation Firewood per winter Rainwater harvest Garden size Panel tilt

Looking at a specific parcel in Grimes 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 →

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.