Tex. Spec. Dist. Local Laws Code § 8501.002

This chapter does not affect any existing rights, or existing priorities in the rights, to water from the source of supply. The formation of the authority or a contract for the purchase of water with the authority is not an abandonment or waiver of those rights or priorities and is not an abandonment of the original point of diversion from the source of supply. All those rights existing at the time of the formation of the authority are preserved.