The fund is composed of:
(1) money and assets, including bond proceeds, attributable to the bonds;
(2) investment income earned on money on deposit in the fund and depository interest earned on money on deposit in the state treasury;
(3) money appropriated by the legislature;
(4) repayments of principal and interest on loans made under this subchapter;
(5) administrative fees charged by the board under the bond program;
(6) money disbursed to the fund from the state water implementation fund for Texas as authorized by Section 15.434; and
(7) any other funds, regardless of their source, that the board directs be deposited to the credit of the fund.