(a) The annexation of territory under this subchapter is not final until ratified by:
(1) a majority of the voters voting at a separate election held in the district; and
(2) a majority of the voters voting at a separate election held in the territory to be annexed.
(b) If the district has outstanding debts or taxes, the proposition for the territory's assumption of its proportion of the debts or taxes on annexation shall be submitted at the same time and at the same election.
(c) The manner of holding the election, the election notice, and the manner and time of giving notice of the election under this section are governed by Chapters 49 and 51, Water Code.