Oregon Revised Statutes Water Resources: Irrigation, Drainage, Flood Control, Reclamation § 547.115

Each supervisor before entering upon official duties shall take and subscribe to an oath before some officer authorized by law to administer oaths, that the supervisor will honestly, faithfully and impartially perform the duties devolving upon the supervisor in office as supervisor of the drainage district in which the supervisor was elected, and that the supervisor will not neglect any of the duties imposed upon the supervisor by the Drainage District Act.