First, how about a quick review of the literature?
The Lawson Aquatic Centre was built in 1974. According to the
Recreation Facility Plan from back in 2010 (pages 19-21), the Lawson had an estimated remaining useful lifespan of 15 years (which I guess would be 9 years now). The proposed recommendations then were to build a replacement in three phases. Phase I was to be an indoor leisure aquatics facility (aka water park), Phase II added an outdoor aquatics component, and Phase III (after 2020) was to replace the Lawson with a training and competitive aquatics facility. So along with the Fieldhouse, all phases would form an integrated facility, all located on the same site. The proposed budget for Phase I was $24 million, and Phase II was $3 million, according to Appendix C (page 52). No budget was given for Phase III, probably because it wasn't within the timeline being considered (2010-2020).
The outdoor pools are another story. Dewdney, Maple Leaf and Wascana pools all date back to 1946-1947, with Massey Pool apparently built in 1964. No idea about Regent Pool, but probably around the same era as Massey. According to
this article from two years ago, it would cost up to $35 million to totally rebuild all the pools, or $15 million to refurbish them. The Recreation Facility Plan from 2010 (pages 22-23) recommends replacing Wascana Pool with an outdoor aquatic park (budget of $7.6 million). Massey and Regent pools would continue to be maintained through 2020. Maple Leaf Pool would eventually be replaced with a spray pad ($1.2 million), and Dewdney Pool would be decommissioned, according to Appendix C.