Tex. Transportation Code § 257.025

(a) One or more persons may file a petition with the commissioners court of a county requesting that real property owned by the person or persons be annexed to a road district. The petition must describe the real property by:

(1) metes and bounds; or

(2) lot and block number if there is a recorded plat of the real property.

(b) Before the real property may be annexed to the road district, each petitioner must agree to:

(1) assume the petitioner's share of:

(A) any outstanding bonds, notes, or other obligations of the district; and

(B) any bonds of the district payable in whole or part from taxes that have been approved by the voters but have not been issued; and

(2) authorize the commissioners court to impose a tax on the petitioner's property in each year in which the bonds, notes, or other obligations payable in whole or part from taxes are outstanding to pay the petitioner's share of the indebtedness.

(c) The commissioners court shall hold a hearing to consider the petition and shall give notice of the hearing in the manner required for a hearing for creation of a road district.

(d) The commissioners court may annex the real property described by the petition to the district if the court determines that:

(1) it is to the advantage of the real property to be annexed to the district; and

(2) the real property already in the district will not be injured by the annexation.

(e) If each petitioner agrees to the items specified by Subsection (b), the commissioners court may issue any unissued bonds that have been approved by the voters of the district even though the boundary of the district has been altered by the annexation since the bonds were approved.

(f) If no qualified voter resides on the real property proposed to be annexed to the district, the commissioners court may order the annexation of the real property without further proceedings.

(g) If a qualified voter resides on the real property to be added and there are any outstanding bonds, notes, or other obligations of the district that are payable from taxes, the commissioners court shall order an election to be held in the district, including the real property to be annexed to the district, on the question of the assumption by the real property to be annexed of the district's outstanding and approved but unissued bonds, notes, or other obligations and of the taxes imposed to pay those obligations. Notice of the election shall be given and the election shall be held as provided by law for a bond election in the district.

(h) The order annexing the real property to the district shall provide that the annexation does not take effect unless a majority of the votes cast at the election held under Subsection (g) favor the assumption of the district's outstanding bonds, notes, and other obligations and the imposition of a tax to pay those obligations.