A system for modifying a path of operation of a machine includes a position sensor and a controller. The controller stores the path of operation, receives a plurality of position signals as the work implement moves material along the path of operation, and determines the position of the work surface. The controller further determines an amount of material moved based at least in part upon the position of the work surface and modifies parameters used to determine a subsequent path of operation if the amount of material moved exceeds a predetermined amount.