The corporate limits shall be those existing at the time of ratification of this Charter, as set forth on the official map of the Town or in a written description, and as they may be altered from time to time in accordance with law. An accurate delineation of the current boundaries shall be maintained permanently in the office of the Town Clerk and shall be available for public inspection, as provided in G.S. 160A-22. Immediately upon alteration of the corporate limits, the appropriate filings shall be made in the offices of the Secretary of State, the Duplin or Pender County Register of Deeds, and the appropriate boards of elections, as required by general law.