Cal. PUC § 21605

No proprietor of any permitted airport which is open to the public and has received public funds shall close or suspend operation of the airport, or close an existing runway or taxiway except on a temporary basis for inspection, maintenance, construction, or emergency purposes, without notifying the department in writing 60 days prior to the intended closure or suspension of operations. On its own motion or upon the request of an affected or interested person, the department may conduct a public hearing to determine the impact of the intended closure or suspension of operations, both economically and on the entire state air transportation system. The department may take appropriate action to assist the proprietor in keeping the airport operational and open for public use.