Tex. Local Government Code § 232.204

(a) A county may not require the owner of a tract of land located outside the limits of a municipality who divides the tract into two or more parts to have a plat of the subdivision prepared if:

(1) the lots are sold to adjoining landowners; and

(2) the lots are added to the adjoining parcel of land owned by the purchasers.

(b) The purchaser of a lot described by Subsection (a) shall provide to the commissioners court a metes and bounds description of the adjoining parcel of land owned by the purchaser that has been updated to reflect the addition of the purchased lot to the adjoining parcel of land.

(c) A county may, subject to Subsection (d), in its sole discretion and on a determination that good cause exists, grant an exception to the plat requirements of this subchapter for an individual lot that the county determines:

(1) is located within 50 feet of a connection to a municipal water service;

(2) is adjacent to a public road;

(3) has either:

(A) sufficient space to accommodate a sewer service facility that complies with the model rules adopted under Section 16.343, Water Code; or

(B) a connection to an existing public sewer service within 50 feet; and

(4) a civil engineer registered to practice in this state and not affiliated with the owner of the lot has certified:

(A) has adequate drainage; and

(B) is not in a floodplain.

(d) Before granting an exception under Subsection (c), the commissioners court must make a finding that specifies the reasons for the court's determination that:

(1) good cause exists to grant the exception; and

(2) the lot meets the requirements for the exception under Subsection (c).

(e) The commissioners court shall enter in the record of the court's proceedings:

(1) the court's findings under Subsection (d); and

(2) the information submitted to the court to support the court's determination under Subsection (c).

(f) The commissioners court may adopt rules and procedures necessary to administer and enforce this section.