Cal. Wat. Code § 79793
Notwithstanding any other provision of this division, or of the State General Obligation Bond Law, if the Treasurer sells bonds that include a bond counsel opinion to the effect that the interest on the bonds is excluded from gross income for federal tax purposes under designated conditions or is otherwise entitled to any federal tax advantage, the Treasurer may maintain separate accounts for the bond proceeds invested and for the investment earnings on those proceeds, and may use or direct the use of those proceeds or earnings to pay any rebate, penalty, or other payment required under federal law or take any other action with respect to the investment and use of those bond proceeds, as may be required or desirable under federal law in order to maintain the tax-exempt status of those bonds and to obtain any other advantage under federal law on behalf of the funds of this state.
Ca. Water Code § 79793