(a) District bonds mature not more than 30 years after their date and bear interest at a rate ordered by the commissioners court but not more than six percent annually.
(b) The bonds must provide the interest rate and the time, place, manner, and conditions of payment as ordered by the commissioners court.
(c) The bonds may be payable annually or semiannually.
(d) The bonds must be issued in denominations of not less than $100 nor more than $1,000.