Tex. Water Code § 17.182

Unless used to pay debt service on bonds issued under this chapter, the proceeds from the sale of political subdivision bonds held by the board either shall be credited to the account from which financial assistance was made to the political subdivision, except that accrued interest shall be credited to the interest and sinking fund, or shall be deposited to the credit of the Texas Water Development Fund II, established within the state treasury pursuant to Section 49-d-8, Article III, Texas Constitution. However, no such proceeds shall be deposited to the credit of the Texas Water Development Fund II unless the executive administrator certifies to the board that the transfer of such proceeds into the Texas Water Development Fund II will not cause the board, in the fiscal year the transfer is made, to direct the comptroller to transfer out of the first money coming into the state treasury during that fiscal year funds sufficient for the payment of principal of or interest on water development bonds, other than water development bonds issued for the purposes described in Subsection (e), Section 49-d-7, Article III, Texas Constitution, coming due in that fiscal year.