The pool at our house in Cathedral City (Palm Springs adjacent) only has one drain, and the pool inspector said that because it is grandfathered in, we do not have to replace with the dual drains. How big of a safety issue is it to have only one drain? We are planning to replaster the pool in the next year or so and thought that would be the best time to switch to two drains, if it is really necessary. I have not yet gotten pricing for adding another drain, but I have asked for it.