Tex. Local Government Code § 232.074

(a) Unless a person has completed the installation of all water and sewer service facilities required by this subchapter on the date that person applies for final approval of a plat under Section 232.073, the commissioners court shall require the subdivider of the tract to execute and maintain in effect a bond or, in the alternative, a person may make a cash deposit in an amount the commissioners court determines will ensure compliance with this subchapter. A person may not meet the requirements of this subsection through the use of a letter of credit unless that letter of credit is irrevocable and issued by an institution guaranteed by the Federal Deposit Insurance Corporation. The subdivider must comply with the requirement before subdividing the tract.

(b) The bond must be conditioned on the construction or installation of water and sewer service facilities that will be in compliance with the model rules adopted under Section 16.343, Water Code.