The surveyor prepares, maintains, and keeps in their office a legal survey record book showing maps of sections, grants, subdivisions, or groups of such areas in sufficient detail so that the location of each is known. The surveyor also maintains a corner stone record book. The information is the basis for determining the location of parcels within the county. In addition, the surveyor supervises all drain construction, reconstruction, and maintenance. They serve as an ex officio member of the county drainage board and serve as a member of the county plan commission.