These rules or one or more specific provision(s) of these rules may be waived by ParksCorp or the BPCA pursuant to the specific terms of a permit where activities necessary or appropriate for the maintenance, operation, construction, public enjoyment, restoration or upkeep of the physical condition of the parks or adjacent areas are involved, as determined by ParksCorp or the BPCA, each in its sole discretion, provided that such waiver shall not be contrary to law.