California Code, Code of Civil Procedure - CCP § 1273.040

(a) Except as provided in subdivision (b), an agreement authorized by this chapter may specify the terms and conditions under which the party acquiring the property may abandon the acquisition, the arbitration proceeding, and any eminent domain proceeding that may have been, or may be, filed. Unless the agreement provides that the acquisition may not be abandoned, the party acquiring the property may abandon the acquisition, the arbitration proceeding, and any eminent domain proceeding at any time not later than the time for filing and serving a petition or response to vacate an arbitration award under Sections 1288, 1288.2, and 1290.6.

(b) If the proceeding to acquire the property is abandoned after the arbitration agreement is executed, the party from whom the property was to be acquired is entitled to recover (1) all expenses reasonably and necessarily incurred (i) in preparing for the arbitration proceeding and for any judicial proceedings in connection with the acquisition of the property, (ii) during the arbitration proceeding and during any judicial proceedings in connection with the acquisition, and (iii) in any subsequent judicial proceedings in connection with the acquisition and (2) reasonable attorney's fees, appraisal fees, and fees for the services of other experts where such fees were reasonably and necessarily incurred to protect his interests in connection with the acquisition of the property. Unless the agreement otherwise provides, the amount of such expenses and fees shall be determined by arbitration in accordance with the agreement.