Texas Natural Resources Code - NAT RES § 161.178. Disposal of Excess Funds

(a) Money in the fund that is not spent for the purposes provided in this chapter shall remain in the fund until there is sufficient money to retire fully bonds issued and sold by the board.

(b) Money in the fund that is in addition to that necessary to retire the bonds shall be deposited to the credit of the General Revenue Fund to be appropriated as provided by law, and the money necessary to retire the bonds shall be set aside and shall remain in the fund.

(c) Money that becomes at a later time a part of the fund after there is sufficient money to retire the bonds shall be deposited to the credit of the General Revenue Fund.