Upon the filing and examination of the report of the surveyor or civil engineer as provided in section 31-206, the county board shall examine the same and, if it finds that the ditch or ditches, drain or drains, is or are necessary for agricultural or sanitary purposes, that they will be conducive to the public welfare, and that the benefits to be derived therefrom will equal or exceed the cost of procuring the right-of-way therefor and the expense of constructing the same, the board shall cause the county clerk to notify all landowners whose lands or lots may be damaged, taken, affected or crossed by such ditch or drain at least five days prior to the day set for hearing said matter. Such notice shall be given in writing by personal service, or by a copy thereof being left at the usual place of residence of the owner or owners of said lands or lots, if the owner or owners of the lands or lots are residents of the county, the notice to be served by the sheriff of the county, unless the owner or owners of the lands or lots shall in writing accept service thereof. If the owner or owners of such lands or lots are nonresidents of the county, then the notice shall be published once each week for three successive weeks in some newspaper published and of general circulation in the county, and if no newspaper is published in the county, such notice shall be published in some newspaper having a general circulation therein. The board shall also cause a notice to be served upon the occupant or occupants or agents, if any, of the lands or lots belonging to any nonresident owner or owners. The notice shall state the time and place when all matters relating to such ditch or drain will be heard, the land affected thereby, and the time of the appointment of the appraisers as hereinafter provided.