The official grade of the streets of the city of Pinole shall be established by the Council by resolution at any regular meeting; provided, however, that after the first day of April, 1914, no grade shall be established unless notice of the same stating the time and place of hearing has been posted for ten days prior thereto on each piece, lot or tract of property affected thereby or served personally for the same period on each owner of property affected thereby and an opportunity given by the Council for hearing the objections of the owner of the property to the proposed establishing of the official grade. (Prior code § 45).