The necessary engineering services required by the City shall be provided for by ordinance of the Council. The engineering services may be provided by contracting with a registered civil engineer licensed to practice within the State of Ohio, or by the creation of a Department of Engineering. 
   The Mayor taking office on January 1, 1972, shall investigate the various methods of providing necessary engineering services for the City and shall submit a report of his investigation and his recommendations to the Council not later than July 1, 1973.