The department of conservation and development may, but, by this chapter, shall not be required to, operate the canal and the locks thereof, and, as a part of such operation, permit the use of the canal by pleasure and commercial craft, or pleasure craft alone, passing through or requiring the use of such locks. In the event of such operation, the department of conservation and development shall adopt and formulate, from time to time, a tariff of tolls and lock charges to be paid by the craft so using the canal.