It shall be the duty of the Authority so to conduct its affairs as to secure that its revenue (including any grant towards revenue made to it in pursuance of section 10(1) of this Act) is not less than sufficient to meet charges properly chargeable to revenue account, taking one year with another.

It shall be the duty of the Authority, in framing and carrying out proposals involving it in substantial outlay on capital account, to act on lines settled from time to time with the approval of the Secretary of State; and it shall also be the duty of the Authority to secure that any subsidiary of the Authority acts on those lines in framing and carrying out proposals involving the subsidiary in such an outlay.

The Secretary of State may, with the approval of the Treasury, give to the Authority a direction as to any matter relating to the establishment or management of reserves or the carrying of sums to the credit of any reserves or the application of any reserves for the purposes of the Authority.