Wash. Rev. Code § 3.38.070
A county legislative authority for a county that has a single district but has multiple locations for courtrooms may establish separate electoral districts to provide for election of district court judges by subcounty local districts. In any county containing a city of more than four hundred thousand population, the legislative authority of such a county shall establish such separate electoral districts. The procedures in chapter 3.38 RCW for the establishment of district court districts apply to the establishment of separate electoral districts authorized by this section.
RCW 3.38.070
Intent-1989 c 227: "It is the intent of the legislature to continue to provide the option for local election of district court judges where a county district court with multiple courtrooms is unified into a single district court for operational and administrative purposes." [ 1989 c 227 s 1.]