(a) A county judge is entitled to an annual salary supplement from the state in an amount equal to 18 percent of the state base salary paid to a district judge as set by the General Appropriations Act in accordance with § 659.012(a) if at least 18 percent of the:
(1) functions that the judge performs are judicial functions; or
(2) total hours that the judge works are in the performance of judicial functions.
(b) To receive a supplement under Subsection (a), a county judge must file with the comptroller‘s judiciary section an affidavit stating that at least 18 percent of the:
(1) functions that the judge performs are judicial functions; or
(2) total hours that the judge works are in the performance of judicial functions.

(c) The commissioners court in a county with a county judge who is entitled to receive a salary supplement under this section may not reduce the county funds provided for the salary or office of the county judge as a result of the salary supplement required by this section.