The Secretary of State may from time to time, after consultation with a new water and sewerage authority, direct them—
(a)to pay to him, on a date specified in the direction, such sum as may be so specified, being a sum not required; or
(b)to invest, in such manner as may be so specified, such sum as may be so specified, being a sum not immediately required,
for the exercise of their functions nor apart from this section payable under or by virtue of any provision of this Act.