Thurston planning panel reopens debate on Grand Mound density, sewer and traffic limits

The Thurston County Planning Commission discussed whether to meet state-mandated housing allocations for the Grand Mound urban growth area by allowing higher-density zoning in one large parcel or by requiring mixed-use housing on larger arterial commercial lots.

The debate centered on an applicant-initiated UGA expansion that includes two properties — Black Lake Quarry (BLQ) and the Wilmovsky site — and on how changes to density rules could help the county meet an identified need for low- and moderate-income housing. Planning staff told commissioners the Grand Mound UGA needs about 223 units in the 0–80% area median income bracket; commissioners and residents questioned whether proposed zoning changes would translate into buildable, affordable homes.

Why it matters: Thurston County must show it has land capacity across income brackets under state housing requirements. Commissioners said the Wilmovsky site could yield “116 to 464 units,” but staff advised that the type of housing that can be built under the current r-4 to r-16 zoning would not produce enough units in the lowest affordability band. That…