Before the city shall undertake any project the cost of which, or part thereof, is to be borne by the abutting property, or the property benefited or its owner, the City Council shall hold a public hearing after public notice as hereinabove provided. Upon such hearing, the City Council shall hear the objections of interested parties, and may adjourn from time to time to complete such hearing. After such hearing, the City Council may make such changes, additions or omissions as it deems proper in the proposed local improvement without the necessity of a further hearing, and may by resolution direct the commencement of said local improvement either by city forces or by contract.