Tex. Spec. Dist. Local Laws Code § 9068.051

After the district is organized and has obtained voter approval for the issuance of, or has sold, bonds payable wholly or partly from ad valorem taxes, land within the district boundaries subject to taxation that does not need or utilize the services of the district may be excluded and other land not within the boundaries of the district may be included within the boundaries of the district without impairment of the security for payment of the bonds or invalidation of any prior bond election, as provided by this section and Sections 54.740 through 54.747, Water Code.