All the ordinances and rules in the world will not make this partying problem go away. Unfortunately, these people feel they are entitled to do whatever they wish. They were trespassing; they did damage to private property and it is doubtful that any of them feel the least bit guilty for anything other than the fact they got caught.
All of the individuals in attendance at that party should be fined enough to help replace the garage they ruined. Students who were there, whether drinking or not, should be suspended from school for at least one quarter. If the parents of any of these irresponsible people complain, then fine them as well.
Until our younger generations are taught (at home) to respect other people and their property, they will continue to act out and behave badly. Kids should have fun, but not this way, and frankly I, for one, cannot comprehend how this type of behavior can be considered “fun.”