When I used to be a Boy Scout we were taught to never ever set up in the low areas because of flash flooding. One time I actually did and I was lucky that my tent was just filled with water. Never made that mistake again.
Well that area is decieving because it does not seem low lying.. You go up a mountain to get there. The average camper prolly does not realize it's a valley. We always camp up on the moutain, and we still got flooded.