Before adoption by the board of supervisors in any year, the cost of the payments authorized by this section and Section 31739.5 shall be determined by a qualified actuary and the board of supervisors shall, with advice of the actuary, provide for the payment of such cost in such manner as to fully fund the benefits on a sound actuarial basis, including use of available funds in the reserves provided in Section 31592.2 with the approval of the retirement board, or an increase in the employer rates of contributions, or a combination of these sources of payments. This actuarial determination shall be made only upon authorization by the board of supervisors.
Upon adoption by any county providing benefits pursuant to this section, of Article 5.5 (commencing with Section 31510) of this chapter, the board of retirement shall, instead, pay those benefits from the Supplemental Retiree Benefits Reserve established pursuant to Section 31510.8.
Ca. Gov. Code § 31681.8