Tex. Loc. Gov't Code § 271.024

If a governmental entity is required by statute to award a contract for the construction, repair, or renovation of a structure, road, highway, or other improvement or addition to real property on the basis of competitive bids, and if the contract requires the expenditure of more than $100,000 from the funds of the entity, the bidding on the contract must be accomplished in the manner provided by this subchapter.