(a) The board shall prepare and approve an annual budget.
(b) The budget must contain a complete financial statement, including a statement of the:
(1) outstanding obligations of the district;
(2) amount of cash on hand to the credit of each fund of the district;
(3) amount of money received by the district from all sources during the previous year;
(4) amount of money estimated to be available to the district from all sources during the ensuing year;
(5) amount of the balances expected at the end of the year in which the budget is being prepared; and
(6) estimated amount of revenues and balances available to cover the proposed budget.