I dont know too much about the raid however destroying a damn can take care of several things. One is if the damn was used for electrical power then you can ellimante a major soarce of power, the damn being destroyed could also be used to flood major areas of land and it can also be destroyed if the damn was hiding other things. But I dont know eneogh about the raid itself, I have read many books on the subject but do not recall much about it.