A unit of state government may pay a claim resolved in accordance with this subchapter only from money appropriated to it for payment of contract claims or for payment of the contract that is the subject of the claim. If money previously appropriated for payment of contract claims or payment of the contract is insufficient to pay the claim or settlement, the balance of the claim may be paid only from money appropriated by the legislature for payment of the claim.
Tex. Gov't. Code § 2260.054