Cal. Wat. Code § 11706
Any provisions not inconsistent with this part may be contained in the proceedings authorizing the issuance of bonds which limit, restrict, or regulate the holding, deposit, investment, and application of money consisting of the proceeds from the sale of the bonds or the revenues received from the operation of the project, and such provisions shall constitute a contract with the holders of the bonds and be binding upon the department as long as the bonds are outstanding. The proceedings authorizing the issuance of bonds may also contain any provisions not inconsistent with this part which are determined by the department and the Treasurer to be necessary or desirable to improve the marketability of the bonds or lower the interest cost on the bonds to the department.
Ca. Water Code § 11706