Each system of the authority shall operate independently of the others and shall be self-sustaining, except insofar as the board may by resolution combine any of the systems which, in the opinion of the board, shall be advisable and economical and which by the general laws of the state or any federal laws or any contracts or indentures are not required to be operated separately. Telecommunications service shall continue to be maintained as a separate division pursuant to §7-36-107(a)(6).