The damages for the taking or injury of any property for use as a public wharf, pier, or bulkhead shall include full compensation for the value of said property taken or injured; and, in the event that the property so taken or injured shall constitute a part of a plant used as an entirety, the damage to owner or tenant shall be assessed by taking the difference in market value of such plant as a whole, including buildings, machinery, fixtures, and other equipment, installed and used in said plant, before and after such taking or injuring, and notwithstanding that part of said plant may be separated by a street or public highway.