Access to water is one of the biggest challenges facing the planet today. We have to address the underlying causes, like climate change, overconsumption, waste and pollution. However, that alone won't overcome the problem -- not in time for millions of people in need of fresh water. Fortunately there's some incredible technology emerging to recycle or create new sources of water--dowsing rods for the 21st Century. eventy-one per cent of the world's surface is covered by water. But the vast majority of that is ocean--salt water we can neither drink nor use to irrigate our crops.