A traditional Australian way of saving water in a drought is to drop a housebrick into the cistern to reduce the volume of water in it, although this takes away the option of using an extra big flush when needed.
In 1980, with $130,000 government assistance, Bruce Thompson of Caroma developed a cistern with two buttons and flush volumes (11.0 litres and 5.5 litres). This wasn't easy because the toilet bowl had to be redesigned to make sure less water could still remove the waste.
Thompson's Duoset cistern saved 32,000 litres of water a year per household when it was trialled in a small town in South Australia. Caroma's success led to legislation in every state but New South Wales to make dual volume toilets compulsory in new buildings.
In 1994 the company completely redesigned the toilet in stylish porcelain in a modern 'organic shape'. Its 6 and 3 litre dual flush cistern and matching bowl halved the amount of water normally flushed away.
This combination of style and environmental awareness attracted attention in the tough European sanitaryware market and exports began soon after. The product is now shipped to more than 30 countries worldwide.