Tex. Water Code § 54.741
An application for exclusion can only be considered by the board if an application is filed by an owner of other land lying outside the boundaries of the district seeking inclusion of land that can be served in a practical manner by the district of at least equal value to the land proposed for exclusion. Such land must be included within the district boundaries and taxing jurisdiction of the district simultaneously with the exclusion of the land proposed for exclusion. Such included land must be of sufficient acreage to avoid an impairment of the security for payment of voted and issued bonds and any other contract obligations payable or secured, in whole or in part, from ad valorem taxes or revenues of the district.
Tex. Water Code § 54.741