The City Council shall establish rates to be paid for the use of heat and improvements supplied by the City for the production and distribution of heat, and such rates shall be called heat rates. Such heat rates shall be a lien in the nature of a real estate tax upon the real estate so supplied with heat, improvements for the delivery of heat, or both, and shall be collected and enforced under such regulations and ordinances as the City Council shall prescribe. (Amended 2011, No. M-6, § 5, eff. May 6, 2011.)