California Code, Code of Civil Procedure - CCP § 1255.010

(a) At any time before entry of judgment, the plaintiff may deposit with the State Treasury the probable amount of compensation, based on an appraisal, that will be awarded in the proceeding. The appraisal upon which the deposit is based shall be one that satisfies the requirements of subdivision (b). The deposit may be made whether or not the plaintiff applies for an order for possession or intends to do so.

(b) Before making a deposit under this section, the plaintiff shall have an expert qualified to express an opinion as to the value of the property (1) make an appraisal of the property and (2) prepare a written statement of, or summary of the basis for, the appraisal.The statement or summary shall contain detail sufficient to indicate clearly the basis for the appraisal, including, but not limited to, all of the following information:

(c) On noticed motion, or upon ex parte application in an emergency, the court may permit the plaintiff to make a deposit without prior compliance with subdivision (b) if the plaintiff presents facts by affidavit showing that (1) good cause exists for permitting an immediate deposit to be made, (2) an adequate appraisal has not been completed and cannot reasonably be prepared before making the deposit, and (3) the amount of the deposit to be made is not less than the probable amount of compensation that the plaintiff, in good faith, estimates will be awarded in the proceeding. In its order, the court shall require that the plaintiff comply with subdivision (b) within a reasonable time, to be specified in the order, and also that any additional amount of compensation shown by the appraisal required by subdivision (b) be deposited within that time.