If the boundaries of any city, township, or rural precinct are changed in the manner provided by law, the county auditor shall update the registration records of every registered voter whose place of residence is affected thereby. It shall not be necessary for any registered voter whose registration has been changed from one precinct to another, by a change of boundary, to apply to the county auditor for a transfer of registration. The county auditor shall mail a notice to each registered voter.
RCW 29A.16.070