Sec. 15. The ordinance may also provide that the works shall be contracted for, constructed, and paid for under the supervision and approval of consulting engineers employed or designated by the board and satisfactory to the original bond purchasers, successors, assigns, or nominees. The original bond purchasers, successors, assigns, or nominees may be given the right to require that the security given by:
(1) contractors; and
(2) any depository of the proceeds of bonds or revenues of the works or other money pertaining to the works;
be satisfactory to the purchasers, successors, assigns, or nominees.