Last Wednesday, I attended a CNU-sponsored "curbside chat" by Chuck Marohn. Chuck is one of the founders of the Strong Towns movement. He's a civil engineer so, naturally, he mostly talks about infrastructure. His basic message is that suburban sprawl seems cheap to towns and cities because the developers pay for most of the infrastructure. But that infrastructure has a finite lifespan. Eventually it must be replaced. And when the time comes to replace it, the tax revenue generated by the low-density, low-value sprawl pattern won't cover the cost.
Chuck's from a small town in Minnesota, so he has a different perspective on growth than those of us in Austin or other fast-growing places in the sunbelt. A lot of Midwestern towns and cities stopped growing, or actually began to lose people, a long time ago. They are now saddled with worn-out roads and streets, leaky water pipes, and broken sewer systems that they cannot replace without outside help. Some cities are deliberately abandoning some infrastructure, or even whole neighborhoods, because they can't cover the cost any more.
Cities like Austin should pay attention. Austin is a very young city. More than half the city was built within the last 40 years. And it will continue to add new subdivisions a rapid clip, which will hold down the average age of our infrastrcture. But eventually the growth will end or slow to a trickle, and then we'll be stuck with a lot of aging infrastructure, and, thanks to our low-density growth patterns, a high ratio of infrastructure to people.
Obviously, cities should aim to grow their existing neighborhoods. Adding people to an existing neighborhood saves the need for new infastructure and provides more bodies to pay for the existing infrastructure when it wears out.
But my main reaction while listening to Chuck was, What do you think we're going to do about it?
Austin's comprehensive plan assumes the city will add 750,000 people over the next 30 years. I think that's optimistic -- 350,000 to 400,000 is more likely, based on last decade's rate of growth. The metro area will likely add well over a million, though.
Almost all of that growth will be greenfield. There is no political will to allow the kind of upzoning that would be necessary to accommodate even a small fraction of that growth within existing neighborhoods. Consider central Austin. It added just 8,000 people between 2000 and 2010, while Austin proper added 133,000 and the metropolitan area added 450,000 people. The central city did a bit better job adding structures than people -- its housing stock expanded by 15,000 units, or roughly 12%. But the last decade was the decade of condo towers sprouting downtown, the densification of West Campus, the Triangle, Mueller, condos in East Austin, and massive greenfield development in southeast Austin. And all that development lead to a piddly net increase of 12% of the housing stock.
Don't get me wrong. I think we should let central Austin get much denser, for many reasons. Austin is lucky because people actually want to move to the central city. Lots of cities spend a lot of time and money trying to solve the problems caused by central-city flight. But given the contentiousness of last decade's development battles, I don't see Austin allowing the kind of development we need to house even 50,000 new people in the central city.