(a) Not later than the 10th day after the date of the commissioner's election, each commissioner shall:
(1) take and subscribe an oath of office with conditions in the oath as provided by law for members of the commissioners court of a county; and
(2) enter into a good and sufficient bond in the amount of $1,000 payable to the district, conditioned on the faithful performance of the commissioner's duties as a commissioner.
(b) The bond of a commissioner must be approved by the board.