About a year ago, I was faced with a similar decision. I was deciding between engineering at UBC, SFU, UW, and U of T. I heard that UW really has an outstanding program and it's quite well known now, but I chose UBC because in the end it made more sense. UBC is by no means a slouch compared to any other university in Canada. The science faculty appears to be pretty good and very big. A lot of my friends are in it.
If you live 10 minutes from UBC, then you are extremely lucky, because I know a lot of people who come here despite an hour and a half commute one way every morning and afternoon/night. I've got a 40 minute drive every morning, and in the afternoon if it's rush hour, closer to an hour. It's even better if you're able to live here for free, I'm assuming you can live with your parents or something.
I agree with the things Martin said. Vancouver is just such a great place to live that that alone might be worth it to stay. It's so unbelievably temperate here, with very little winter weather, yet we have great skiing in just a half hour drive. It's really beautiful here compared to the other places I've seen and lived in. UBC is really a nice place to be because there's a really rich student life. Always lots of stuff happening on what is perhaps the most beautiful campus in Canada, definitely one of the most beautiful in North America. There's a pub, and even a decent arcade if you're into that.
I know I sound like a brochure, but this stuff is important in my opinion. If it's less trouble to stay here in Vancouver, I'd recommend you stay. Not like you'd be getting a poor education here, and it's not quite on the same level as waterloo in terms of prestige, but it's up there.