Neb. Rev. Stat. § 31-907

After a determination has been made as provided in section 31-904 , if at any time a petition signed by one or more owners of lots and lands affected is filed with the board requesting: (1) The cleaning of a road ditch; (2) the cleaning of a public or private ditch which is used for drainage by more than one landowner; (3) the cleaning of a watercourse; (4) the construction of any dike, revetment or bank protection; or (5) the installation of a culvert or drain, the board shall make a determination as to whether said improvement would be conducive to public health, convenience or welfare.