Cal. Gov. Code § 450
The permanent seat of government of the state is at the City of Sacramento, but the Governor shall designate by written proclamation an alternative temporary seat of government for use in the event of war or enemy-caused disaster, or the imminence thereof. The proclamation shall be filed with the Secretary of State. A different temporary seat of government may be so designated at any time as circumstances indicate the desirability of such a change.
The Director of General Services, and any other state agency as directed by him, shall provide such facilities of any kind at the temporary seat of government as appear desirable for the functioning of the government of the state at the temporary seat of government in the event it becomes necessary, pursuant to this section.
Ca. Gov. Code § 450