The provisions of this chapter shall not be construed to devolve any additional powers upon county councils with regard to public service districts, special purpose districts, water and sewer authorities, or other political subdivisions by whatever name designated, (which are in existence on the date one of the forms of government provided for in this chapter becomes effective in a particular county) and such political subdivisions shall continue to perform their statutory functions prescribed in laws creating such districts or authorities except as they may be modified by act of the General Assembly, and any such act which dissolves a district or absorbs its function entirely within the county government shall provide that such act shall be effective only upon approval of such abolition or absorption by favorable referendum vote of a majority of the qualified electors of the district voting in such referendum. Upon the dissolution of any district within a county and the assumption of its function by the county government, the county shall take title to the property of the district and assume all of its debts and obligations which shall be retired by charges or assessment of taxes in those areas of the county receiving benefits from the facilities of the district; provided, however, notwithstanding any other provision of law, when any county council under existing law is authorized to appoint members to the governing body of a public or special service district or a water resources commission within the county and such governing body by resolution directed to the council requests a change in the size or manner in which members of such governing body are selected, the council may by ordinance effect such changes and the council action shall have the full force and effect of law from the effective date of the ordinance.