(a) Except as provided by Subsection (c) of this section, bonds purchased by the board shall be supported by:
(1) all or part of the net revenue from the operation of the project;
(2) taxes levied by the political subdivision for the purpose; or
(3) a combination of taxes and net revenue, and revenue from other available sources.
(b) The board may require that the bonds be supported both by taxes and by net revenue from the operation of the project in any ratio the board considers necessary to fully secure the investment. The board shall establish other conditions and requirements it considers to be consistent with sound investment practices and in the public interest.

(c) Bonds purchased by the board under Subchapter K of this chapter may be additionally supported by money provided to the political subdivision by the federal or state government and by private donations.
(d) With respect to projects for which financial assistance is made available under this chapter, the Texas Water Development Board shall file semiannually with the Bond Review Board a report on the performance of loans made by the Texas Water Development Board in connection with the projects. The Bond Review Board shall review the reports filed by the Texas Water Development Board under this subsection to assess the adequacy of the security for the bonds purchased. The filing dates and the contents of the reports must comply with any rules adopted by the Bond Review Board.