California Code, Government Code - GOV § 7267.7

(a) If the acquisition of only a portion of a property would leave the remaining portion in such a shape or condition as to constitute an uneconomic remnant, the public entity shall offer to acquire the entire property if the owner so desires.

(b) A person whose real property is being acquired in accordance with this chapter may, after the person has been fully informed of his or her right to receive just compensation for the property, donate the property, any part thereof, any interest therein, or any compensation paid therefor to a public entity determined by the person.