(a) The district may set aside an amount of proceeds from the sale of bonds issued under this subchapter for the payment of interest expected to accrue during construction and a reserve interest and sinking fund. The resolution authorizing the bonds may provide for setting aside and using the proceeds as provided by this subsection.
(b) The district may use proceeds from the sale of the bonds to pay any expense necessarily incurred in accomplishing the district’s purpose, including any expense of issuing and selling the bonds.

(c) The proceeds from the sale of the bonds may be temporarily invested in direct obligations of the United States maturing not later than the first anniversary of the date of investment.