An earlier line of discussion on the "New Jackson Hole" post made it clear we needed a new thread for discussion of the urban growth boundary (or whatever terminology you want to use).
In my limited understanding of the issue, the towns of Carrboro and Chapel Hill have attempted to limit growth by creating a line in the sand and refusing to extend city services, including water and sewer, past that line. Since much of the land north of town doesn't perk and since much of the land west of Carrboro is in the University Lake watershed, this means that only lots larger than 5 acres can easily get through the process for development.
Unfortunately, there are a couple of problems. As was pointed out in the other thread, the agreement between the county and cities will expire at some point and there will be a lot of pressure to extend the boundary to increase the tax base. Also, as has been pointed out by a lot of balanced growth advocates, a 5 acre minimum is not exactly going to stop development... instead it's just going to create an extra large series of suburban neighborhoods around the city. Now I don't THINK that's what everyone had in mind, but it seems like that is what is coming to pass, whether we like it or not.
Balanced growth folks often advocate more extreme measures like 20-25 acre minimum lot sizes and more stringent regulations, but others argue that this would only continue to increase the cost of living in Chapel HIll and Carrboro and create a situation similar to Boulder where everyone except rich folk are priced out of living there. I'm sure there's a way to make it work to where we can have our rural areas be preserved and still have a diversity of folks living in town, but haven't heard anyone put that bold vision out there yet. Anyone want to try?