Cal. Gov. Code § 9036
If a disaster occurs, the Legislature shall convene itself in special session immediately after such disaster first occurs, which session shall convene at the permanent seat of government in the City of Sacramento or at the temporary seat of government as established by law if the session cannot be held in the City of Sacramento. At such special session the Legislature may fill any vacancies in its membership, pursuant to law, and may consider and act upon any subject of legislation that is designed to relieve or alleviate the consequences of such disaster or to restore or continue state and local government in connection therewith, together with such other subjects within the scope of legislative regulation or control as are specified by concurrent resolution adopted by both houses of the Legislature.
Ca. Gov. Code § 9036