Except as otherwise provided in Sections 27550.1 and 27641.1 or in this section, or in Section 21123 or 34711 of the Water Code, or in any landowner voting district, as defined in paragraph (8) of subdivision (b) of Section 10500 of the Elections Code, a person is not eligible to an elective county or district office, unless the person is a registered voter of the county or district in which

the duties of the office are to be exercised at the time that nomination papers are issued to the person or, if appointed to the elective office to fill a vacancy, at the time of the appointment of the person.