Juvenile court shall be administered by the superior court, except that by local court rule and agreement with the legislative authority of the county this service may be administered by the legislative authority of the county. Juvenile probation counselor and detention services shall be administered by the superior court, except that (1) by local court rule and agreement with the county legislative authority, these services may be administered by the county legislative authority; (2) for the consortium in existence on July 23, 2017, if a consortium of three or more counties, located east of the Cascade mountains and whose combined population exceeds two hundred thousand, jointly operates a juvenile correctional facility, the county legislative authorities may prescribe for alternative administration of the juvenile correctional facility by ordinance; and (3) in any county with a population of one million or more, probation and detention services shall be administered in accordance with chapter
13.20 RCW. The administrative body shall appoint an administrator of juvenile court, probation counselor, and detention services who shall be responsible for day-to-day administration of such services, and who may also serve in the capacity of a probation counselor. One person may, pursuant to the agreement of more than one administrative body, serve as administrator of more than one juvenile court. If a county participating in a consortium authorized under subsection (2) of this section withdraws from participation, the withdrawing county may rejoin the consortium at a later time so long as a majority of the consortium members agree.