Tex. Local Government Code § 81.033

(a) This section applies only to a commissioners court of a county that has a population of more than 4,500, is located within 100 miles of an international boundary, and contains no incorporated territory of a municipality.

(b) If approved at an election held in the county for that purpose, the commissioners court has, in addition to the powers given to it under this code or other law, all the powers of the governing body of a Type A general-law municipality, including the powers contained in Subtitle A, Title 7, except that:

(1) the commissioners court may not regulate an activity outside the county;

(2) the commissioners court may not regulate a tract of land that is appraised as agricultural or open-space land by the appraisal district;

(3) the commissioners court may not exercise the powers of a municipality under Chapter 211 or 213; and

(4) if this code or other law provides for a procedure by which a county exercises a power, the commissioners court must use that procedure.

(c) For an election under this section, the ballot shall be prepared to permit voting for or against the proposition: "Granting (name of county) County the authority to enact ordinances in the same manner as a general-law municipality."

(d) If a majority of the votes cast at the election favor the proposition, the commissioners court has the powers described by Subsection (b).

(e) If territory of the county becomes incorporated in a municipality:

(1) in the area outside the municipality and outside the municipality's extraterritorial jurisdiction, the authority of the commissioners court to exercise a power under this section:

(A) expires, on the date of the incorporation, with regard to a subject on which the court has not previously acted under this section; and

(B) continues with regard to a subject on which the court has previously acted under this section; and

(2) in the area in the municipality or in the extraterritorial jurisdiction of the municipality, the authority of the commissioners court to exercise a power under this section expires on the 180th day after the date of the municipal incorporation.

(f) On receipt of a petition signed by at least 10 percent of the county's registered voters, the commissioners court shall call an election on the repeal of an order or ordinance authorized by this section on the first uniform election date that occurs after the 90th day after the date the petition is filed. The order or ordinance is repealed if a majority of the votes cast at the election favor repeal. A petition requiring an election under this subsection may not be filed sooner than the fifth anniversary of the date of an election held under this subsection.