California Code, Government Code - GOV § 53700

(a) To reduce any of its indebtedness.

(b) To fund or refund any such indebtedness, whether relating to general obligation bonds or to the obligations represented by special assessment bonds for the unpaid principal upon any assessment levied prior to September 15, 1935 pursuant to state law in which the lien is special as to a particular property described in the assessment or bond, or whether the bonds are to be paid and discharged from an annual levy in accordance with the assessed value of all of the lands in a district.