Council may, by ordinance grant to any individual, company or corporation operating a public utility, the right to extend the appliances and service of such utility. All such extensions shall become a part of the aggregate property of the utility and shall be subject to all of the obligations and reserved rights applicable to the property of the utility by virtue of the ordinance providing for its construction and operation.
   The right to use and maintain any such extension shall expire with the original grant of the utility to which the extension was made or any renewal thereof.