That's what I was wondering. I was hired once by a RE developer to study Lake Elsinore (Lake "Hell, senor") to see what would be needed to make it attractive lake front property. After a week, I went to him and said "Well, first, we need to find 20 billion gallons of water". That was the end of that job.
But...yeah it's shallow.
I remember when that area was in the sticks.....and all Elsinore was really known for was the motorcycle race.
My older sister lived not far from there in the early 80's at Canyon Lake.......