Cal. Gov. Code § 14152

In the performance of any such federally financed work the department may adopt any procedure as to the letting of contracts for, the conduct of, or the payment for, the work, that is requested by the authorized agents of the federal agencies designated in Section 14150, or required by federal laws, rules, or regulations. In the absence of any such requirement or request, such work shall be performed pursuant to the laws of this State.