Buying Land in Spokane County, Washington

Living above a sole-source aquifer: what it means for a land buyer

Spokane County's defining physical fact, for land-use purposes, is what lies beneath much of it: the Spokane Valley-Rathdrum Prairie (SVRP) Aquifer, a roughly 370-square-mile groundwater system spanning Spokane County and Kootenai and Bonner Counties in Idaho, holding an estimated 10 trillion gallons of water and supplying drinking water to more than 500,000 people. It's also unusually fast-moving, with flow rates reaching as much as 60 feet a day in places -- meaning contamination introduced at the surface can reach drinking-water supplies quickly. The U.S. Environmental Protection Agency designated the SVRP a Sole Source Aquifer in 1978 in direct response to local concerns about vulnerability to contamination, and Spokane County responded in 1985 by creating its own Aquifer Protection Area (APA), a special funding district authorized under RCW 36.36 that assesses fees specifically tied to water withdrawal and on-site sewage disposal within its boundary.

A real, dated 2025 vote: the APA gets renewed and expanded

The APA's original fee structure had gone unchanged since 1985, and it needed voter reauthorization to continue. On August 5, 2025, voters within the Aquifer Protection Area approved Ballot Measure 1 with about 74% support, renewing the APA for another 20 years -- and, notably, expanding it for the first time since 2004 to bring the City of Spokane itself into the APA alongside the cities of Spokane Valley, Millwood, and Liberty Lake, plus overlying unincorporated county land. Under the renewed structure, most residential parcels pay a $15 annual fee, while rural parcels relying on septic systems for on-site sewage disposal pay $30 a year, and multi-family, commercial, and other non-residential properties are billed according to their water-meter size. These fees began showing up as a separate line on property tax bills in 2026. For a buyer evaluating rural Spokane County acreage on septic, the APA's now-broader footprint and its specific dual fee (water withdrawal plus septic) are a real, current cost and compliance factor to confirm before closing, not a historical curiosity.

For the full mechanics of the fee structure and how it interacts with new septic permitting, see the dedicated septic-systems page for Spokane County.

A critical areas ordinance in flux as of 2026

Spokane County was working through a public rewrite of its Critical Areas Ordinance as of spring 2026, with a public draft dated April 23, 2026 circulating for comment. Among the critical-area categories the ordinance addresses is the Critical Aquifer Recharge Area (CARA) designation, which generally restricts activities likely to significantly increase the risk of contaminating the drinking-water aquifer below -- a designation that, given the SVRP Aquifer's footprint, can realistically apply to a meaningful share of county land outside the immediate urban core as well as within it. Because this rewrite was still in draft form as of this research, any specific CARA standard, buffer, or allowed-use list should be confirmed directly with Spokane County's Building and Planning department against the currently adopted (not draft) version of the ordinance before a purchase decision is finalized.