Tex. Water Code § 17.077

(a) Except as provided by Subsection (b) of this section, and except for proceeds from the sale of bonds and proceeds from the sale, refunding, or prepayment, of political subdivision bonds acquired in carrying out the purposes in Article III, Sections 49-c, 49-d, 49-d-1, 49-d-2, 49-d-6, and 49-d-7, of the Texas Constitution, and the proceeds from the sale, refinancing, or other liquidation of the investments made under Section 17.083 of this code which shall be deposited in the fund that provided the money for the investment, all money received by the board in any fiscal year, including all amounts received as repayment of loans to political subdivisions and interest on those loans, shall be credited to the clearance fund. Money in the clearance fund may be transferred at any time to the interest and sinking fund until the reserve in that fund is equal to the average annual principal and interest requirements on all outstanding bonds.

(b) Any amounts received as repayment of financial assistance made to a political subdivision under Subchapter K of this chapter and interest on that financial assistance shall be deposited to the economically distressed areas clearance fund. Money in the economically distressed areas clearance fund may be transferred at any time to the economically distressed areas interest and sinking fund until the reserve in that fund is equal to the average annual principal and interest requirements on all outstanding bonds.