(a) The board may pay the cost of acquiring and repairing sanitary sewer systems from:
(1) the proceeds of sale of bonds or other obligations issued by the district;
(2) revenue obtained from maintenance taxes; or
(3) revenue from the operation of the district's improvements.
(b) The board may pay the cost of maintaining and operating sanitary sewer systems with funds obtained from maintenance taxes or from operating revenues. The board may not pay these costs with borrowed money.