So, one detail that the sharp-eyed readers have noticed is that each house could be completely self-contained for electricity (solar/wind), waste (septic/compost) and water (well). True, but this makes the space each house needs much greater, and severely restricts where you can put 3000+ people! A three-bedroom house (septic is calculated from the number of bedrooms, not baths) needs approximately 1/4 acre of drainage, more if the soil doesn't drain well, and even more if it freezes. Septic zoning in upstate NY (say, Lake Placid) is minimum 1/2 acre leech field per 3 bedrooms, for example. And you need an oversize septic tank for when the ground is solid, which has to be pumped regularly. Meaning roads have to accommodate septic trucks (low grade and maintained) and, of course, this septic waste has to go somewhere. Who is going to take it? The problem is magnified for common buildings like meeting halls and for restaurants and businesses.
Solar is great, if somewhat spendy to set up, IF you get enough sun. Wind, ditto. And your well needs to be deep enough not to become contaminated by the septic system. (I've worked on a well-drilling rig, and I would like the contract for GBstan if he gets that far. Cash only, paid up front, per 1000 feet.) You will also need water storage for fire fighting, usually a pond or lake. (We're going to meet this again in governance.) And the thought of all the Tea Party wives trying to convince their husbands to sort, recycle and compost makes me smile. It's like they are re-creating the hippy communes of the '70s - anyone remember the Farm in Tennessee?
Anyway, you still need roads. Can't get away from that.