Texas Government Code - GOV'T § 852.002. Referendum on Participation

(a) If qualified voters representing at least 10 percent of the total votes cast at the most recent regular municipal election petition the governing body of a municipality for an election on the issue of participation in the retirement system by the municipality or specified departments of the municipality, the governing body shall make arrangements for an election to be held before the 61st day after the day the petition is filed.

(b) If a majority of the votes cast in an election under this section favor municipal or departmental participation in the retirement system, the governing body of the municipality immediately shall elect to participate.