Tex. Water Code § 16.141

The board may execute contracts with the United States and with state agencies and political subdivisions and with others to the extent authorized for the development and operation of recreational facilities at any project in which the state has acquired an interest. Income received by the board under these contracts may be used for the same purposes as income from the sale of water. The legislature may appropriate money for the development and operation of recreational facilities at projects in which the state has acquired an interest.