Off-Grid Living in Spokane County, Washington

Spokane County, Washington sits in an interesting spot for off-grid hopefuls: it's unincorporated county land governed by the Spokane County Building & Planning Department, but water rules bring in the Washington Department of Ecology, and health/septic matters go through the Spokane Regional Health District (SRHD), a joint city-county agency. That mix of authorities means you're never dealing with just one office here, so keep notes on who told you what.

Zoning is countywide and zone-specific. The Rural Traditional (RT) zone and other rural classifications allow a range of uses per the county's Rural Zones Matrix, but only one residential use per lot unless otherwise specified, and anything not listed in the use tables is prohibited by default. I could not confirm from official sources whether truly raw occupancy (tent, no structure) is allowed outright in any zone, so call Building & Planning before you set up camp long-term.

Dwellings, tiny homes, RVs: the county's main path for small secondary units is the ADU process. RVs as temporary housing during construction appear tied to an active building permit and SRHD-approved sanitation, consistent with state practice, but I didn't find a Spokane-specific ordinance spelling out tiny-house-on-wheels standards. Confirm directly with the county.

Building permits are issued locally but hinge on proving water availability, a well log and SRHD sign-off on water quantity/quality almost everywhere. In the Little Spokane watershed and the Spokane Valley-Rathdrum Prairie (SVRP) aquifer areas, state-driven mitigation rules kick in, sometimes requiring a Mitigated Residential Building Permit and a water right senior to base flow under state law.

Septic systems and holding tanks are permitted and inspected by SRHD under the statewide WAC framework, with recurring inspection reporting required. Illegal discharge to natural outlets is banned by county code. Composting toilets fall under that same state WAC baseline, no separate county page turned up.

Greywater reuse isn't addressed in a distinct county ordinance I could find, so it defaults to state WAC rules administered by SRHD, treat this as unsettled until you ask.

Rainwater harvesting for non-potable use appears unrestricted at the county level, the county's focus is stormwater and floodplain management, not catchment.

Wells are generally permit-exempt at small domestic scale, but the Little Spokane and SVRP areas carry extra mitigation-certificate or water-bank requirements set by the state and implemented locally.

Full utility disconnection: no standalone ban exists, but any permitted dwelling still needs an approved water source and wastewater system, well and septic satisfy that, total omission does not appear to be a legal option.