Wash. Rev. Code § 36.70.310
Members of planning agencies shall inform themselves on matter affecting the functions and duties of planning agencies. For that purpose, and when authorized, such members may attend planning conferences, meetings of planning executives or of technical bodies; hearings on planning legislation or matters relating to the work of the planning agency. The reasonable travel expenses, registration fees and other costs incident to such attendance at such meetings and conferences shall be charges upon the funds allocated to the planning agency. In addition, members of a commission may also receive reasonable travel expenses to and from their usual place of business to the place of a regular meeting of the commission. The planning agency may, when authorized, pay dues for membership in organizations specializing in the subject of planning. The planning agency may, when authorized, subscribe to technical publications pertaining to planning.
RCW 36.70.310