As used in this article:
(a)
“Necessary property” means property to be used for a public use for which the public entity is authorized to acquire property by eminent domain.(b)
“Substitute property” means property to be exchanged for necessary property.
Source:
Section 1240.310, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CCP§ionNum=1240.310..