Cal. Civ. Proc. Code § 1245.245
(a) Property acquired by a public entity by any means set forth in subdivision (e) that is subject to a resolution of necessity adopted pursuant to this article shall only be used for the public use stated in the resolution unless the governing body of the public entity adopts a resolution authorizing a different use of the property by a vote of at least two-thirds of all members of the governing body of the public entity, or a greater vote as required by statute, charter, or ordinance. The resolution shall contain all of the following:
(3) A declaration that the governing body has found and determined each of the following:
(b) Property acquired by a public entity by any means set forth in subdivision (e) that is subject to a resolution of necessity pursuant to this article, and is not used for the public use stated in the resolution of necessity within 10 years of the adoption of the resolution of necessity, shall be sold in accordance with the terms of subdivisions (f) and (g), unless the governing body adopts a resolution according to the terms of subdivision (a) or a resolution according to the terms of this subdivision reauthorizing the existing stated public use of the property by a vote of at least two-thirds of all members of the governing body of the public entity or a greater vote as required by statute, charter, or ordinance. A reauthorization resolution under this subdivision shall contain all of the following:
(3) A declaration that the governing body has found and determined each of the following:
(e) The following property acquisitions are subject to the requirements of this section:
(f) If the public entity fails to adopt either a new resolution pursuant to subdivision (a) or a reauthorization resolution pursuant to subdivision (b), as required by this section, and that property was not used for the public use stated in a resolution of necessity adopted pursuant to this article or a resolution adopted pursuant to subdivision (a) or (b) between the time of its acquisition and the time of the public entity’s failure to adopt a resolution pursuant to subdivision (a) or (b), the public entity shall offer the person or persons from whom the property was acquired the right of first refusal to purchase the property pursuant to this section, as follows:
(2) For property that was a single-family residence at the time of acquisition, at an affordable price, which price shall not be greater than the price paid by the agency for the original acquisition, adjusted for inflation, and shall not be greater than fair market value, if the following requirements are met:
(C) If the single-family residence is offered at a price that is less than fair market value, the public entity shall impose terms, conditions, and restrictions to ensure that the residence will either:
(j) At least 60 days before selling the property pursuant to subdivision (g), the public entity shall make a diligent effort to locate the person from whom the property was acquired. At any time before the proposed sale, the person from whom the property was acquired may exercise the rights provided by this section. As used in this section, “diligent effort” means that the public entity has done all of the following: