Cal. Pub. Cont. Code § 20429

Before being entitled to a contract, the bidder to whom the award was made, or the owners who have elected to take the contract, must advance to the superintendent of streets, for payment by him, the cost of publication of the notices, resolutions, orders and matters required under the proceedings prescribed in this division, and of such other notice as may be deemed requisite by the legislative body, together with all other incidental expenses incurred up to the time of entering into the contract, including the estimated cost of any acquisition which the legislative body may determine to be payable at said time, but limited to the amount specified in the notice inviting bids pursuant to Section 5241 of the Streets and Highways Code. All other acquisition costs shall be payable at the time of the delivery to the contractor, or his agent, or assigns, of the warrant, assessment and diagram as provided in Section 5375 of the Streets and Highways Code. The legislative body may waive the payment in advance of all or any part of the incidental expenses and acquisition costs by resolution adopted not later than the time of ordering the work. The waiver must appear in the notice inviting bids.