If you live on rhe Santa Ana River flood plain...
I can’t view the flood maps well enough on my phone to check but I don’t think so. I’m at 875 feet above sea level and well east/south of the Santa Ana River, near the base of Saddleback. Even if the Prado dam went it would have to flood a hell of a long way and up a hell of an elevation to reach me. I don’t think there’s much chance of Irvine lake spilling over and even the reservoir behind my house would flood down into the arroyo below it and then down Santa Margarita Parkway before to went up the hill where I live.