California Code, Public Resources Code - PRC § 31152

(a) The lands are specifically identified in a certified local coastal plan or program as agricultural lands, or, in the case of San Francisco Bay, the lands as so identified in the bay plan, the Suisun Marsh Protection Plan, or in any other local plan which the bay commission determines to be consistent with such plans.

(b) There is no other reasonable means, including the use of police power, of assuring continuous use of such lands for agricultural purposes.