An irrigation system includes a central pivot and a series of mobile towers connected to the central pivot and to one another by support structure. Each mobile tower has wheels and a motor for driving at least one of the wheels. A control system operates the motors to maintain alignment of the mobile towers and the central pivot while preventing power usage of the system from exceeding a maximum power threshold. The control system determines in which sequence to operate the motors to maintain alignment of the mobile towers while operating no more than a selected number of the motors simultaneously.