Cal. Streets and Highways Code § 27189

In cases of great emergency, including but not limited to states of emergency as defined in subdivision (b) of Section 8558 of the Government Code, the board of directors of a bridge and highway district may proceed at once to replace or repair any and all structures, roadway, or property of the district that may be rendered unusable or unsafe without adopting the plans, specifications, strain sheets or working details or giving notice for bids to let contracts. The work may be done by day labor under the direction of the board, by contract, or by a combination of the two. If the work is done wholly or in part by contract, the contractor shall be paid the actual cost of the use of machinery and tools and of material and labor expended by him in doing the work, plus not more than 15 percent to cover all profits, supervision, and other expenses. No more than the lowest current market prices shall be paid for materials. Not less than the general prevailing rate of per diem wages for work of a similar character in the locality in which the work is performed, fixed as provided in Chapter 1 (commencing with Section 1720) of Part 7 of Division 2 of the Labor Code, shall be paid to all workmen employed on such works.