(a) The commissioners court shall impose a tax for the benefit of the district on all property in the district subject to district taxation.
(b) The commissioners court shall impose the tax to:
(1) pay the interest on and create a sinking fund for bonds assumed or issued by the district for hospital purposes as provided by this chapter;
(2) pay for indebtedness assumed by the district;
(3) provide for the operation and maintenance of the hospital or hospital system, including medical or other health facilities; and
(4) when requested by the board and approved by the commissioners court, make improvements and additions to the hospital system, including medical and other health facilities, and acquire necessary sites by purchase, lease, or condemnation.