This graphical display shows two abstraction events where water was taken from the lake to make snow. This can only be done when the temperature is low enough for freezing. If the lake level ever drops to the ‘stage decrease’ threshold at 1799.6m ASL, an alarm is generated and text messages are sent to selected NZSki employees to warn that the lake level is down to within 20cm of the consent limit at 1799.4m ASL.