(a) In this section, “voter-approval tax rate” means the rate equal to the sum of the following tax rates for the district:
(1) the current year‘s debt service tax rate;
(2) the current year’s contract tax rate; and
(3) the operation and maintenance tax rate that would impose 1.08 times the amount of the operation and maintenance tax imposed by the district in the preceding year on a residence homestead appraised at the average appraised value of a residence homestead in the district in that year, disregarding any homestead exemption available only to disabled persons or persons 65 years of age or older.
(b) This section applies only to a district that is not described by § 49.23601 or 49.23602.

(c) If the board of a district adopts a combined debt service, contract, and operation and maintenance tax rate that would impose more than 1.08 times the amount of tax imposed by the district in the preceding year on a residence homestead appraised at the average appraised value of a residence homestead in the district in that year, disregarding any homestead exemption available only to disabled persons or persons 65 years of age or older, the qualified voters of the district by petition may require that an election be held to determine whether to reduce the tax rate adopted for the current year to the voter-approval tax rate in accordance with the procedures provided by Sections 26.075 and 26.081, Tax Code.