California Code, Streets and Highways Code - SHC § 5374.1

The amount of any contribution for the cost and expenses of the work shall be paid by the city to the contractor, or his agent, or assigns, upon delivery of the warrant, assessment and diagram, or prior to said delivery, may be paid in installments, for work completed, during the progress of the work. Notice that there will be progress payments must appear in the invitation for bids.