SCT Controller reported SNA Tower has closed four times due to evacuation. Reporter stated lack of established procedures to manage the traffic and confusion over airspace status created an unsafe environment.

Narrative

SNA Tower evacuated and we went ATC 0. I work SCT TRACON and not having a Tower to a busy airport feels unsafe. The 7110 has some procedures for this but it's not meant for the middle of the day and busy; so we improvised. Arrival sector Tustin had CTAF on speaker to listen to when the aircraft would land. We would take that as cancellation of IFR. Then the next arrival could go in. The departures I'm not sure what grey legal measures were used. This operation has happened at least 4 times and its unsafe. There's no good procedures for it. Also management thinks SNA is still a class C. During all this we (the TRACON) conducted a Runway change; again without a Tower. Once we had turned the airport around one aircraft got away from us and departed opposite direction from everyone else. At the same time its not the aircraft's fault since its an uncontrolled airport. We need better procedures for this. We need clarification on canceling IFR vs landing. What would the spacing for departures be? Is a temporary non-towered airport still class C?