Tex. Water Code § 51.516

On adoption of the plan of taxation provided in Section 51.512(b)(4) of this code, the district, under the limitations of this subchapter, may apply separately, differentially, equitably, and specifically its taxing power and lien to a defined area or designated property to provide money to construct, administer, maintain, and operate improvements and facilities peculiar to the defined area or the designated property.