We are at the gunite stage with plumbing run to the pad and under pressure. I did not plan on an overflow and a friend just suggested I add one. I'm not really concerned about water overflowing during heavy rains, but more for afterwards as I understand the skimmers won't work well. It looks like my Pentair bermuda skimmers do NOT have a knock out to easily connect up an overflow drain. Rather than trying to alter the pool now, I'm wondering if setting up a manual valve at the pad would be better. My filter is a Pentair 520 cartridge, so no back flow valve to dump water. What are your thoughts on adding a manual valve that diverts the water from the pool return to another pipe that's run to the back of the pool? I can move the valve and turn on filter mode and it would pump water out.