(a) This section applies only to a county:
(1) that is located adjacent to an international border; and
(2) in which a military installation and a national recreation area are located.
(b) The commissioners court of a county to which this section applies may acquire, construct, or operate a water supply system or a sewage system to serve unincorporated areas of the county.
(c) The county may enter a management or lease agreement with another public or private entity for the operation of a county water or sewage system acquired or constructed under this section.
(d) The county may apply for and receive grants or other assistance from a state or federal governmental entity to implement this section.
(e) The county may own, operate, or maintain a water or sewer utility in the same manner as a municipality under Chapter 402.
(f) A county may not construct, operate, or maintain a water supply system or sewage system in an area previously served by the county's water supply or sewage system after the area is annexed by a municipality and the municipality begins providing to the area water or sewer services previously provided by the county.
(g) This section does not authorize a county to sell water for a purpose other than for local use.