I had a contractor build a gunite infinity pool for me about two months ago. He recently came by and punched a hole near the top of the catchment basin/collection trough, through the decorative tile and all the way through the concrete of the pool wall, to the dirt in which the pool sits. He said that this was nescessary for drainage purposes, otherwise, if the catchment basis collects too much water, such as from rain storms and including from overflow from the main part of the pool, it will simply overflow. He said this will allow the catchment basin to drain into the ground. While I don't know anything about pool drainage, punching a hole through the pool so that it can drain into the ground if the water reaches a certain level just seems wrong to me. Could anyone tell me whether this is how a catchment basin on an infinity pool typically drains, or has my pool contractor dones something wrong?