I'm going to spout some dragon nonsense now so please don't take me seriously (I am a FIRM believer in the "it's your story you write it the way YOU want to) but I just wanted to give you something to think about: You have your dragon VERY far away from her/his hoard..Any dragon and especially a Red would most likely never travel more than a few feet from her/his hoard while in her/his lair. Now with that being said she/he of course has to drink (and far less frequently eat) But most likely she/he would have her Kobold slaves/followers bring the water to her/him. With that being said Reds have a super-inflated ego and for her/him to be staring at her/his reflection in the pool would be right on character. As long as the pool was very near her/his hoard. Obviously I have had WAY too much coffee today and have NOTHING better to do.