Cal. Civ. Proc. Code § 1036

In any inverse condemnation proceeding, the court rendering judgment for the plaintiff by awarding compensation, or the attorney representing the public entity who effects a settlement of that proceeding, shall determine and award or allow to the plaintiff, as a part of that judgment or settlement, a sum that will, in the opinion of the court, reimburse the plaintiff’s reasonable costs, disbursements, and expenses, including reasonable attorney, appraisal, and engineering fees, actually incurred because of that proceeding in the trial court or in any appellate proceeding in which the plaintiff prevails on any issue in that proceeding.