(a) The district may issue, without an election, bonds and other obligations secured by:
(1) revenue other than ad valorem taxes; or
(2) contract payments described by Section 9040.153.
(b) The district must hold an election in the manner provided by Chapters 49 and 51, Water Code, to obtain voter approval before the district may impose an ad valorem tax or issue bonds payable from ad valorem taxes.