Tex. Loc. Gov't Code § 395.0515

A political subdivision may not increase the amount of an impact fee for three years from the later of the date the fee was adopted or most recently increased, if applicable. Nothing in this section prohibits the political subdivision from implementing an impact fee collection schedule that allows less than the maximum adopted impact fee to be collected or phased in up to the maximum adopted impact fee for a period not to exceed ten years, as authorized by this chapter.