(a) Council, upon the recommendations of the City Engineer, shall determine the costs of opening any street, alley or other public way. Council shall apportion the actual costs among abutting property owners, unless:
(1) The city assumes the costs of the opening; or
(2) One or more property owners voluntarily assumes the entire costs of opening in writing.
(b) The statement of the estimated costs of opening and the method of assessment under this section shall be contained in any resolution by Council approving the opening.