Any area adjacent to any district created under Sections 19-5-215 through 19-5-241 and situated within the same county as the district, and not being situated within the corporate boundaries of any existing municipality, may be annexed to and become a part of such district by the same procedure prescribed in Sections 19-5-215 through 19-5-241 for the original creation of the district. All costs incident to the publication of notice and all other costs incident to the hearings, election and proceedings shall be paid by the board of supervisors.