Notwithstanding any other provision of law, the department is authorized to retain all miscellaneous funds generated by the operation of its park, historic, and recreational sites and facilities for use in the operation and maintenance of those sites and facilities. Any such funds not expended for this purpose in the fiscal year in which they are generated shall be deposited in the state treasury, provided that nothing in this Code section shall be construed so as to allow the department to retain any funds required by the Constitution of Georgia to be paid into the state treasury; provided, further, that the department shall comply with all provisions of Part 1 of Article 4 of Chapter 12 of Title 45, the "Budget Act," except Code Section 45-12-92, prior to expending any such miscellaneous funds.