Cal. Fin. Code § 7263

Bonds of any other political subdivision, public corporation, or district of the State of California (herein referred to generally as public corporations) having the power, without limit as to rate or amount, to levy taxes to pay the principal and interest of those bonds upon all property within its boundaries subject to taxation by the public corporation, if the net direct debt of that public corporation together with its net overlapping debt does not exceed 25 percent of the assessed valuation of the taxable property within its boundaries according to the last official equalized county assessment roll.