As a Brisbane Landscaper I've seen floods and droughts in the last five years. Today we use a combination of methods to conserve water. These include initial garden design ie. plant selection, sub surface irrigation drip lines - far more efficient than sprinklers, automatic controllers connected to rain sensors that stop watering in wet periods and dual water connections that use rainwater (tanks) when available and convert to mains water supply as required. http://www.greenscenegardenscope.com.au