Off-grid site report

Lewis County, WA

46.6632, -122.9668 · 210 ft elevation

Read this before you act on anything below. This is my researched starting point for Lewis County, WA, 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 rulesLewis County, WA

Zoning & raw-land occupancy

Varies locallyLewis County has countywide zoning (LCC Title 17) with rural districts each carrying their own permitted-use chart; most rural zones require around one dwelling unit per five acres, but this varies by district, so confirm your parcel's zone with the county. source

Dwellings, tiny homes & RVs

RestrictedRVs and park trailers occupied more than 60 days are treated as mobile homes and must meet siting/inspection rules unless in a licensed RV park or used for temporary construction housing; used mobile homes need an approved inspection insignia. Tiny houses on foundations follow the state building code baseline. source

Building permits & codes

Generally allowedLewis County Community Development requires permits for most construction, alteration, or occupancy changes, and starts new development through a Master Site Review that flags needed county, state, and federal permits. source

Septic & composting toilets

Generally allowedThe Lewis County Onsite Sewage Program handles septic permitting including soil evaluation, and covers systems (including registered composting toilets) up to fairly large daily capacities; any work beyond the tank needs a permit. source

Greywater reuse

Unclear - verifyNo Lewis County-specific greywater ordinance was found; this appears to default to Washington State Department of Health rules, so confirm with county Environmental Health or state DOH. source

Rainwater harvesting

Generally allowedWashington Department of Ecology's statewide policy allows rainwater harvesting if used on the same property and collected from existing, non-dedicated structures; no added Lewis County restriction was found. source

Private wells & water rights

Varies locallySmall domestic wells generally qualify for the state's groundwater permit exemption administered by Ecology's Southwest Regional Office, while Lewis County's Water Program handles Group B systems and well-site inspections. source

Living disconnected from utilities

Unclear - verifyNo standalone county ordinance bans full utility disconnection, but an approved septic/composting system and approved water source must clear Master Site Review before a building permit is issued. source

Open the full county page with sources →

Sun30-year normals

Peak-sun hours, annual average: 3.6 hrs/day
Worst month (sizes an off-grid array): 1.3 hrs/day
Yearly output per 1 kW of panels: 982 kWh

JFMAMJJASOND

Weather1991-2020

Precipitation: 47 in/yr
Heating degree days: 4,649 (moderate)
Frost-free season: Apr 13 to Oct 31

How far help isstraight-line

Hospital Providence Centralia Hospital: 3.5 mi
Fire station Chehalis Fire Department: 0.2 mi
Hardware store Ewe and I Yarn, LLC: 0.3 mi
Grocery Safeway: 0.8 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 98532).

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

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.