Va. Code § 15.2-855
Within ninety days after the adoption of the urban county executive form of government, the board, after holding a public hearing thereon, shall divide the county into from five to eleven districts. Each district shall be composed of contiguous and compact territory and shall be so constituted as to give, as nearly as is practicable, representation in proportion to the population in the district.
These districts shall serve as the electoral divisions for elections of members of the urban county board of supervisors, and as sanitary districts under the provisions of Article 5 (§ 15.2-858), and shall have such other functions as are specified herein.
Each district shall have at least one of its residents who is a qualified voter of the district appointed to the local planning commission of the county and to the county school board. Each member of the county school board shall be appointed for terms and serve in accordance with all the provisions of § 15.2-837.
Va. Code § 15.2-855