Tex. Water Code § 15.318

Sec. 15.318. PRICE OF SALE: FACILITIES ACQUIRED UNDER CONTRACTS WITH THE UNITED STATES. (a) The price of the sale or transfer of a state facility acquired on or subsequent to September 1, 1981, under a contract with the United States shall be the sum of the direct cost of acquisition, plus an amount of interest calculated by multiplying the lending rate in effect at the time of acquisition, by the amount of board money disbursed for the acquisition of the facility times the number of years and fraction of a year from the date or dates of disbursement of the money to the date or dates of sale or transfer, plus the board's cost of operating and maintaining the facility from the date of acquisition to the date of the sale or transfer of the facility, less any payments received by the board from the lease of the facility or the sale of water from it.

(b) If, in transferring any contract, the board remains in any way directly, conditionally, or contingently liable for the performance of any part of the contract, then the transferee, in addition to the payments prescribed by Subsection (a) of this section, as applicable, shall pay to the board annually one-half of one percent of the remaining amount owed to the other party to the contract, and shall continue these payments until the board is fully released from the contract.