This field have a few big deep depressions in the middle of the field and needs a way for water to drain out. Adding infield ditches could lower the earthworks but at the cost of reduced machinery efficiency and these ditches require maintenance.
Follow this dropbox link for the example survey and unlocked osd file.
Proposed Cut/Fill Map
An OptiSurface4D design has been calculated to let water drain out of the field in any direction. A special 'ridge' subzone, marked by red boundary, was used by the designer to prevent water to exit to the south but instead let all water exit in the east. Significant smoothing was applied in the main slope and the cross slope directions and maximum grades were limited to 2%. This resulted in a smooth design with earthworks of 304 m3/ha (114 yd3/ac).