Where the Authority, in exercise of the powers conferred upon them by any enactment, commence any work from which revenue may after its completion be derived, they may, during such period not exceeding ten years, from the commencement of that work as they determine, charge to capital as part of the cost of that work interest on any money raised to defray—
(a)the cost of acquisition of lands for the purpose of that work; and
(b)the expenses of constructing or carrying out that work.