CA Civ Proc Code Section 1240.410

(a)

As used in this section, “remnant” means a remainder or portion thereof that will be left in such size, shape, or condition as to be of little market value.

(b)

Whenever the acquisition by a public entity by eminent domain of part of a larger parcel of property will leave a remnant, the public entity may exercise the power of eminent domain to acquire the remnant in accordance with this article.

(c)

Property may not be acquired under this section if the defendant proves that the public entity has a reasonable, practicable, and economically sound means to prevent the property from becoming a remnant.