Texas Local Government Code - LOC GOV'T § 552.061. Application of Subchapter to Certain Municipalities

(1) have all or a major part of its territory in a county with a population of more than 25,000; or

(2) be located in a county in which at least 60 percent of the total area is regularly covered by water and in which is located the majority of the total area of a wildlife refuge for species of wildlife on the federal endangered species list.