Bonds in the total amount of three hundred million dollars ($300,000,000), exclusive of refunding bonds issued pursuant to Section 53170.5, or so much thereof as is necessary, may be issued and sold to provide a fund to be used for carrying out the purposes expressed in this part and to be used to reimburse the General Obligation Bond Expense Revolving Fund pursuant to Section 16724.5 of the Government Code. The bonds shall, when sold, be and constitute a valid and binding obligation of the State of California, and the full faith and credit of the State of California is hereby pledged for the punctual payment of both principal of, and interest on, the bonds as the principal and interest become due and payable.