Colo. Const. art. XX, § 4

(1) The people of the city and county of Denver are hereby vested with and they shall always have the exclusive power in making, altering, revising or amending their charter.

(2) and (3) (Deleted by amendment, L. 2000, p. 2778, effective upon proclamation of the Governor, L. 2001, p. 2391, December 28, 2000.)

(4) Any franchise relating to any street, alley, or public place of the said city and county shall be subject to the initiative and referendum powers reserved to the people under section 1 of article V of this constitution. Such referendum power shall be guaranteed notwithstanding a recital in an ordinance granting such franchise that such ordinance is necessary for the immediate preservation of the public peace, health, and safety. Not more than five percent of the registered electors of a home rule city shall be required to order such referendum. Nothing in this section shall preclude a home rule charter provision which requires a lesser number of registered electors to order such referendum or which requires a franchise to be voted on by the registered electors. If such a referendum is ordered to be submitted to the registered electors, the grantee of such franchise shall deposit with the treasurer the expense (to be determined by said treasurer) of such submission. The council shall have power to fix the rate of taxation on property each year for city and county purposes.