The treasurer and collector may appoint as many deputies within the number allowed by the board as may be necessary for the discharge of the duties of their offices, the deputies to hold office at the pleasure of the appointing officer and subject to the powers of the board. Appointments shall be in writing and filed in the office of the district. These deputies shall take and file an oath in the manner required of their principals before assuming the duties of office.
Ca. Water Code § 21187