Tex. Educ. Code § 55.15

Proceeds from the sale of the bonds may be used for paying interest on the bonds during the period of the acquisition or construction of any facilities to be provided through the issuance of the bonds, and for providing a reserve for the payment of the principal of and interest on the bonds, and such proceeds may be placed on time deposit or invested, until needed, to the extent, and in the manner provided, in the bond resolution.