Only one crossover or walkway across the dune area is permitted for each parcel. It shall run, generally, the shortest practical course between the landward edge or toe of the dune and the bayward edge or toe of the dune, and shall not exceed four feet in width. The surface of the crossover is to remain the natural composition of the dune, a NJDOT non-angular mix 1-5 soil aggregate or roll-out beach mat. The crossover shall be fenced on both sides through the use of sand fencing and connect with the existing sand fence enveloping the dune. Any grading or excavation associated with the installation of the crossover shall not result in the lowering of the beach or dune design specifications. In the event that any crossover shall be or become, in the opinion of the Borough, a substantial detriment to the development and maintenance of the continuous protective dune, the owner of the premises shall be required to repair and/or replace approved materials sufficient to return the dune to its designed specifications.