After the official map has been prepared and recommended by the local planning commission it shall be certified by the commission to the governing body of the locality. The governing body may then approve and adopt the map by a majority vote of its membership and publish it as the official map of the locality. No official map shall be adopted by the governing body or have any effect until approved by ordinance duly passed by the governing body of the locality after a public hearing, preceded by public notice as required by § 15.2-2204. Within thirty days after adoption of the official map the governing body shall cause it to be filed in the office of the clerk of the circuit court.