Imagine a home that could recycle two-thirds of the water it uses. No need to imagine. New technology to do just that was recently approved for use in drought-parched California, and the company behind it claims it could be looking at a $15 billion business ahead.

"In five years time, every new home will have a water recycler in it," said Ralph Petroff, chairman of Nexus eWater, the Australia-based company behind the technology.