Off-grid site report

Whitman County, WA

47.0079, -117.1410 · 2,464 ft elevation

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

Zoning & raw-land occupancy

Varies locallyWhitman County has countywide zoning under Title 19, including Agricultural and Cluster Residential Districts with farmland buffers; what's allowed depends on the specific district, per the County Code of Ordinances. source

Dwellings, tiny homes & RVs

Unclear - verifyNo county-specific rule on tiny houses on wheels or long-term RV occupancy was found; state baseline standards likely apply, but this is not confirmed for Whitman County. Ask the Building & Development Division. source

Building permits & codes

Generally allowedThe Whitman County Building & Development Division issues building, plumbing, and mechanical permits for unincorporated areas of the county under state building code. source

Septic & composting toilets

Generally allowedWhitman County Public Health administers on-site sewage (OSS) permitting under state WAC 246-272A/246-272B, starting with a site evaluation. Composting toilets aren't separately addressed, so confirm with the department. source

Greywater reuse

Varies locallyNo Whitman County-specific greywater ordinance was found; the state WAC 246-274 framework is presumed to apply, but whether the county adds local requirements is not confirmed. source

Rainwater harvesting

Generally allowedNo county restriction on non-potable rainwater catchment was found; state DOH guidance treats rainwater as an alternative water source, with more scrutiny only for potable use.

Private wells & water rights

Varies locallyIndividual wells are common outside city limits and are regulated by the Washington Department of Ecology for construction and water rights, with most domestic wells under a withdrawal exemption; Whitman County Public Health requires water testing once a source is established. source

Living disconnected from utilities

Unclear - verifyNo standalone county ordinance banning off-grid or utility-disconnected living was found; practical compliance depends on meeting building, septic, and water-source requirements separately.

Open the full county page with sources →

Sun30-year normals

Peak-sun hours, annual average: 4.5 hrs/day
Worst month (sizes an off-grid array): 1.7 hrs/day
Yearly output per 1 kW of panels: 1,253 kWh

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Weather1991-2020

Precipitation: 20 in/yr
Snowfall: 27 in/yr
Heating degree days: 6,278 (cold)
Frost-free season: May 9 to Sep 24

How far help isstraight-line

Hospital Whitman Hospital & Medical Clinics: 14.7 mi
Fire station Farmington Volunteer Fire Department: 7.1 mi
Hardware store Four Star Supply: 13.4 mi
Grocery Schaut's Marketplace: 0.0 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 99130).

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.