(a) Except as provided by Section 13.0045, the operation, maintenance, and improvement of state parks shall be financed from the general revenue fund, the state parks account, other accounts that may be authorized by law, and donations, grants, and gifts received by the department for these purposes.
(b) No donation, grant, or gift accruing to the state or received by the department for the purpose of operating, maintaining, improving, or developing state parks may be used for any purpose other than the operation, maintenance, or developing of state parks.