On the hearing of the petition, all parties interested may appear and be heard, and the county board may grant or reject the application. If granted, it shall appoint a licensed surveyor to make the survey, with whom a written contract for the performance of the work must be made, secured by a sufficient bond executed by the surveyor and approved by the board. Two weeks’ published notice of the appointment of the surveyor, specifying the date when the survey will begin, must be given. At the appointed time, the work shall begin, and shall continue without unnecessary delay until completed.