Tex. Water Code § 51.517

If a district adopts the tax plan and assumes the powers in Section 51.512(b)(4) of this code, or if required to conserve and protect the public welfare, the district, in the manner provided in Sections 51.518-51.524 of this code, may provide, pay for, maintain, and operate improvements, service, or facilities peculiar to a designated area or defined property which do not affect the whole district.