California Code, Public Utilities Code - PUC § 30967

After the formation of the improvement district or districts within the district pursuant to this article, all proceedings for the authorization and issuance of bonds of the district for the improvement district or districts shall be limited and shall apply only to the improvement district or districts;  and taxes for the payment of those bonds and the interest thereon shall be levied exclusively upon the taxable property in the improvement district or districts;  and the revenues of the district shall be used only to the extent set forth in the resolution declaring the necessity.