Iowa Code § 468.11: Survey.

1. The engineer shall examine the lands described in the petition and any other lands which would be benefited by said improvement or necessary in carrying out the purposes of the petition.

2. The engineer shall locate and survey such ditches, drains, levees, settling basins, pumping stations, and other improvements as will be necessary, practicable, and feasible in carrying out the purposes of the petition and which will be of public benefit or utility, or conducive to public health, convenience, or welfare.