California Code, Public Utilities Code - PUC § 1216

(a) The finding of the commission on the question of the necessity for the taking and the finding fixing the just compensation to be paid for any property or interest in or to property under Sections 1206 to 1216, inclusive, are final and shall not be subject to modification, alteration, reversal, or review by any court of this state.

(b) The provisions of this part with reference to rehearing and review shall be applicable to the findings of the commission made and filed under this chapter.  Petitions for rehearing shall be filed within 20 days from the date of making and filing the finding as to which a rehearing is desired.

(c) If a finding of the commission made and filed under this chapter is set aside by the Supreme Court or the court of appeal of the State of California, the matter shall be referred back to the commission for further action in a proceeding before the commission, and the commission may, on taking further action, consider the entire testimony theretofore taken in the proceeding before the commission as well as further testimony, if any, presented in connection with further action.