The activities or functions of the county shall, with the exceptions herein provided, be distributed among the following general divisions or departments:
The board may establish any of the following additional departments and commissions and such other departments and commissions as it deems necessary to the proper conduct of the county's business:
Any activity which is unassigned by this chapter shall, upon recommendation of the urban county executive, be assigned by the board to the appropriate department. The board may, upon recommendations of the urban county executive, reassign, transfer or combine any county functions, activities or departments.
Va. Code § 15.2-823