(1) No unincorporated area may be annexed to a municipality unless one of the following conditions first has been met:
(2) The provisions of this section shall not apply to annexations to the city and county of Denver, to the extent that such annexations are governed by other provisions of the constitution.
(3) The general assembly may provide by law for procedures necessary to implement this section. This section shall take effect upon completion of the canvass of votes taken thereon.