Tex. Water Code § 63.337: SUIT TO SET ASIDE OR CORRECT ASSESSMENT.

(a) A property owner with an assessment or reassessment against him or his property may bring suit within 20 days after the assessment or reassessment in any court with jurisdiction to set aside or correct the assessment or reassessment or any proceeding with reference to the assessment or reassessment due to any error or invalidity.

(b) The cost of a suit to set aside or correct an assessment or reassessment shall be paid by the loser of the litigation.

(c) After the 20-day period following the assessment or reassessment, the owner or his heirs, assigns, or successors do not have a right of action or a defense of invalidity of the assessment or reassessment in any action in which the assessment or reassessment is in question, except in case of fraud.

Acts 1971, 62nd Leg., p. 110, ch. 58, Sec. 1, eff. Aug. 30, 1971.