Okla. Stat. tit. 27, § 10
Any person, agency or other entity acquiring real property for public use under the laws of this state shall, as soon as practicable after the date of payment of the purchase price or the date of deposit into court of funds to satisfy the award of compensation in a condemnation proceeding to acquire real property, whichever is the earlier, reimburse the owner for expenses he necessarily incurred for:
Laws 1971, HB 1479, c. 355, § 2, eff. July 1, 1972.