For the purposes of carrying out this part, 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 which have been authorized to be sold for the purpose of carrying out this part. Any amounts withdrawn shall be deposited in the fund. Any money made available under this section shall be returned to the General Fund, plus interest that the amounts would have earned in the Pooled Money Investment Account, from money received from the sale of bonds for the purpose of carrying out this part.