The Director of Finance may authorize the withdrawal from the General Fund of an amount or amounts not to exceed the amount of the unsold bonds that have been authorized by the committee to be sold for the purpose of carrying out this chapter. Any amount withdrawn shall be deposited in the fund. Any money made available under this section shall be returned to the General Fund, plus an amount equal to the interest that the money would have earned in the Pooled Money Investment Account, from money received from the sale of bonds for the purpose of carrying out this chapter.