(a) On final approval of the annual budget, the board shall impose a tax on all property in the district subject to district taxation.
(b) The board shall impose the tax to:
(1) pay the interest on and create a sinking fund for bonds issued or assumed by the district for hospital purposes as provided by this chapter;
(2) provide for the operation and maintenance of the hospital or hospital system;
(3) make improvements and additions to the district's hospital system; and
(4) acquire necessary sites for improvements or additions by purchase, lease, or condemnation.