Wash. Rev. Code § 36.32.560
If a county operating under home rule charter zones pursuant to its inherent charter authority and not pursuant to chapter 35.63 RCW, nor chapter 36.70 RCW, and that county does not provide for the siting of residential care facilities in zones or areas that are designated for single-family or other residential uses, the county shall conduct a review of the need and demand for the facilities, including the cost of any conditional or special use permit that may be required. The review shall be completed by August 30, 1990. A copy of the findings, conclusions, and recommendations resulting from the review shall be sent to the *department of community development by September 30, 1990.
On or before June 30, 1991, each municipality that plans and zones under this chapter shall have adopted an ordinance or ordinances that are necessary to implement the findings of this review, if the findings indicate that such changes are necessary, or shall notify the *department of community development as to why such implementing ordinances were not adopted.
RCW 36.32.560
*Reviser's note: Powers, duties, and functions of the department of community development and the department of trade and economic development were transferred to the department of community, trade, and economic development by 1993 c 280, effective July 1, 1994. The "department of community, trade, and economic development" was renamed the "department of commerce" by 2009 c 565.