Cal. PCC § 7105

(a) Construction contracts of public agencies shall not require the contractor to be responsible for the cost of repairing or restoring damage to the work, which damage is determined to have been proximately caused by an act of God, in excess of 5 percent of the contracted amount, provided, that the work damaged is built in accordance with accepted and applicable building standards and the plans and specifications of the awarding authority. However, contracts may include provisions for terminating the contract. The requirements of this section shall not be mandatory as to construction contracts financed by revenue bonds. This section shall not prohibit a public agency from requiring that a contractor obtain insurance to indemnify the public agency for any damage to the work caused by an act of God if the insurance premium is a separate bid item. If insurance is required, requests for bids issued by public agencies shall set forth the amount of the work to be covered and the contract resulting from the requests for bids shall require that the contractor furnish evidence of satisfactory insurance coverage to the public agency prior to execution of the contract.

(b) For the purposes of this section:

(1) “Public agency” shall include the state, the Regents of the University of California, a city, county, district, public authority, public agency, municipal utility, and any other political subdivision or public corporation of the state.

(2) “Acts of God” shall include only the following occurrences or conditions and effects: earthquakes in excess of a magnitude of 3.5 on the Richter Scale and tidal waves.

(c) Public agencies may make changes in construction contracts for public improvements in the course of construction to bring the completed improvements into compliance with environmental requirements or standards established by state and federal statutes and regulations enacted after the contract has been awarded or entered into. The contractor shall be paid for the changes in accordance with the provisions of the contract governing payment for changes in the work or, if no provisions are set forth in the contract, payment shall be as agreed to by the parties.

(d) (1) Where authority to contract is vested in any public agency, excluding the state, the authority shall include the power, by mutual consent of the contracting parties, to terminate, amend, or modify any contract within the scope of such authority.

(2) Paragraph (1) shall not apply to contracts entered into pursuant to any statute expressly requiring that contracts be let or awarded on the basis of competitive bids. Contracts of public agencies, excluding the state, required to be let or awarded on the basis of competitive bids pursuant to any statute may be terminated, amended, or modified only if the termination, amendment, or modification is so provided in the contract or is authorized under provision of law other than this subdivision. The compensation payable, if any, for amendments and modifications shall be determined as provided in the contract. The compensation payable, if any, in the event the contract is so terminated shall be determined as provided in the contract or applicable statutory provision providing for the termination.

(3) Contracts of public agencies may include provisions for termination for environmental considerations at the discretion of the public agencies.