On the waterpark thing, given that there is only one big indoor mega-waterpark in Canada clearly the economics of the whole thing are iffy. Edmonton lucked out in the 80s and that's probably all there is to it.
That said, many communities have more modestly-scaled waterparks and that is something that inexplicably doesn't exist in Winnipeg. It is weird that places like Steinbach and Portage have such facilities that are far better than anything that exists here.
When my kids were toddlers I visited this place in Richmond, BC... it is nothing spectacular but they sure enjoyed it. It's a municipal facility so it doesn't cost an arm and a leg to enter. It has a wave pool, a play area, a waterslide or two, a regular lap pool and some other amenities. It's hard to believe that nothing like this exists in Winnipeg.