District taxes may be assessed, levied, and collected for any or all of the following purposes:

1. (a) To pay the principal and interest of the bonds issued by the district.
2. (b) To raise money for any of the purposes stated in Sections 6512 and 6660 hereof.
3. (c) To pay any lawful claims against the district.
4. (d) To pay the running expenses of the district.