Texas Civil Practice and Remedies Code - CIV PRAC & REM § 15.0151. Certain Political Subdivisions

(a) Except as provided by a law not contained in this chapter, an action against a political subdivision that is located in a county with a population of 100,000 or less shall be brought in the county in which the political subdivision is located.  If the political subdivision is located in more than one county and the population of each county is 100,000 or less, the action shall be brought in any county in which the political subdivision is located.

(b) In this section, “political subdivision” means a governmental entity in this state, other than a county, that is not a state agency.  The term includes a municipality, school or junior college district, hospital district, or any other special purpose district or authority.