Health & Saf. Code, § 55115

The state does hereby pledge to and agree with the holders of any bonds issued under this part that the state will not limit or alter the rights hereby vested in the local agency to fulfill the terms of any agreements made with the holders thereof or in any way impair the rights and remedies of the holders until the bonds, together with the interest thereon, with interest on any unpaid installments of interest, and all costs and expenses in connection with any action or proceeding by or on behalf of the holders, are fully met and discharged. The local agency is authorized to include this pledge and agreement of the state in any agreement with the holders of the bonds.