(a) The proposed rate for the district sales and use tax imposed under Subchapter B, Chapter 321, Tax Code, may be any rate that is an increment of one-eighth of one percent, that the municipality determines is appropriate, and that would not result in a combined rate that exceeds the maximum combined rate prescribed by Section 321.101(f), Tax Code. The proposed rate for the district sales and use tax imposed under Subchapter B, Chapter 323, Tax Code, may be only:
(1) one-eighth of one percent;
(2) one-fourth of one percent;
(3) three-eighths of one percent; or
(4) one-half of one percent.
(b) A sales and use tax approved under this chapter may be charged in addition to any other sales and use tax authorized by law and is included in computing a combined sales and use tax rate for purposes of any limitation provided by law on the maximum combined sales and use tax rate of political subdivisions.
(c) A municipality that creates a district shall adopt a sales and use tax under Section 321.108, Tax Code, for financing the operation of the district.