Tex. Water Code § 55.366: INSUFFICIENT ASSESSMENTS.

If the assessments made under this subchapter are not sufficient to pay the necessary expenses of the district, the unpaid balance shall be assessed, pro rata, in accordance with the assessments made for the current year. The additional assessments shall be paid under the same conditions and penalties within 30 days from the date of assessment.

Acts 1971, 62nd Leg., p. 458, ch. 58, Sec. 1, eff. Aug. 30, 1971.