Section 193. Power of Council to make special assessments.
   The Council shall have power to provide for the construction, repair and maintenance by contract, or directly by the employment of labor, of all things in the nature of local improvements, and to provide for the payment of any part of the cost of any such improvement by levying and collecting special assessments upon abutting, adjacent and contiguous, or other specially benefited property, or upon the property within the boundaries of a district in which the improvement is located. The amount assessed against the property specially benefited by such local improvements shall not exceed the amount of benefits to such property.
   Provided, that whenever all of the property owners to be assessed for any improvement shall present a petition to the Council requesting the City to make any improvement directly by the employment of labor the cost of which is to be assessed on such abutting property owners, the Council by resolution shall instruct the Director of Public Service to proceed with the work of making such improvement, to employ the necessary labor, and purchase the necessary materials. Such petition shall be in the form prescribed by the Director of Public Service; but no notice shall be required, and publication of the same shall be dispensed with. When such improvement is completed, the cost of the same shall be assessed against the property benefited thereby.
   Provided, further, that when bids are received for any contract work for any improvement, the cost of which is to be assessed upon the lands benefited thereby, the Director of Public Service shall fix a time not less than five days after the receipt of the bids for a public hearing. A notice of the same shall be mailed to the owners of the lands to be assessed, provided their addresses are known or can be ascertained.