How long can they last?

I just started reading my book Under the Dome by Stephen King and it starts off in some ones point of view in a plane right before the dome comes down and mid flight out of no where it crashes into the invisible dome and blows up in the air. The way the book started and how it didn't tell you what the dome was or why it was there it made you want to keep reading. I'm only a few chapters in but a giant semi circle dome fell from the sky on top of a little town called Chester's Mill located in rural Maine. The first thing this made me think of was the Simpson's movie when the government put a dome over their town because of pollution. One of the main characters name is Barbie which is a really odd name for a guy that beats money out of people that didn't pay something they owed, but anyways he was passing through town doing business when the dome came down and was trapped inside along with the citizens of Chester's Mill.

My first thought was how where they going to survive for very long without being able to get supplies from out of town, the town has a couple farms on it enough to feed the small town but where were they going to get water? I also wondered how long it would be before people started rioting and with a very small and limited police force they would not be able to keep a whole town in order for very long. The dome was going to be an ultimate test of how well the citizens of Chester's Mill could work together and for how long they could do it.