Tex. Transportation Code § 313.049: APPEAL OF ASSESSMENT.

(a) A person who owns or claims an interest in assessed property or in an assessed railway may bring suit to contest:

(1) the amount of the assessment;

(2) an inaccuracy, irregularity, invalidity, or insufficiency of the proceedings or contract relating to the assessment or the improvements; or

(3) any matter or thing not in the discretion of the governing body.

(b) The suit must be brought not later than the 15th day after the date the assessment is imposed.

(c) After the period provided by Subsection (b), a person who fails to bring suit:

(1) waives every matter the hearing might have addressed; and

(2) is barred from contesting or questioning in any manner or for any reason:

(A) the assessment;

(B) the amount, accuracy, validity, regularity, or sufficiency of the assessment;

(C) the assessment proceedings; or

(D) a contract relating to the assessment or the improvement.

(d) This section applies to an assessment made under Section 313.048 or 313.050.

Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.