A joint school district and the officers thereof shall possess all the powers and be subject to all of the duties vested in or imposed upon other school districts of the same class and upon the officers thereof, except as otherwise provided by law. Whenever the laws relating to school districts shall provide for any action by a county officer, such action, if required to be performed in behalf of a joint school district, shall be performed by the proper officer of the county to which the joint district belongs, except as otherwise provided by law.
RCW 28A.323.070