Salt Lake will be fine if it continues developing major urban projects in the city. But we can't mask certain problems by just expanding our boundaries. In the 70s, when the city lost its population, just annexing the area that would eventually make up West Valley wouldn't have solved the basic problems of suburban flight except by making the city more suburban in nature.
Moreover, I don't worry about the suburbs passing Salt Lake in population. West Valley, and other suburban communities, are limited as much as Salt Lake in their potential development. Take WVC, the second-largest city in the state. Their population has cooled off compared to the last twenty-years - where it grew by 20.3% in the 80s and 25% in the 90s. This past decade, it only grew 18.9% - which is impressive, but it shows that the extent of the city's growth is limited because, like SLC, its open area is becoming more developed.
Salt Lake still has a 60,000 population edge on West Valley and I suspect it will continue to remain fairly large.
The most important thing is that the city keeps pushing to bring people back into its limits. Just annexing Millcreek or other areas doesn't address the real problem - the city still lags behind a great deal of other cities in condo development. I'd rather emulate a city like Portland than Phoenix, which is a sprawling city literally five-times the size of Salt Lake's area.
Yes, we do have an area of the city that is uninhabitable, or at least underdeveloped, and certain parts of the Wasatch to deal with, but even the city itself, the area where most the residential development resides, can become
more dense without having to go into the suburbs to grow our population. I don't want to be a suburban city. Millcreek is great as a suburb - but it's not really that walkable, doesn't have a central retail center like SugarHouse or 9th and 9th and much of the residential neighborhoods are generally older suburbs that, while charming, are still not exactly urban.
Don't get me wrong, it's not a bad area, and certainly much better developed than a great deal of the newer suburbs - it's just I think we need to focus more on making Salt Lake more dense than expanding the city's limits just to grow the population that way.
Look at it this way - take 84106, the zip code associated with most of SugarHouse and part of Millcreek. That zip gets a
walkable score of 65. Not great compared to a great deal of other areas, but good enough. It's not great because much of it also incorporates the suburban area south of 2700 S and further into the Millcreek area. To further what I'm talking about, the 84124 zip code, which includes part of Holladay, but a very similar makeup to most of Millcreek, gets a walkable score of just 22.
To put that into perspective, 84105, the area code for much of Central City, gets a walkable score of 71.
It shows you how dramatic the area changes the further south you get from downtown. SLC already has pockets of unwalkable neighborhoods and I just don't want to add even more, especially when there is so much work to be done within the city's limits.
I'm confident we can grow Salt Lake from within and not have to rely on expanding our city's limits to bring in more people.