One million people in Adelaide drink water taken from the Murray River. If the salt level keeps rising scientists say Adelaide's water will eventually become undrinkable. When we take more water, and what's left gets saltier, that also affects animals. Platypus used to be common. Now they can barely be found.
Environmentalists say twenty different types of mammals have become extinct.
We can't exactly put in an order for more rain to fill the Murray-Darling system. Scientists say farmers could waste less water. One quarter of the water taken from the Murray-Darling is wasted through bad irrigation techniques, but finding better ways costs lots of money. And that's money most farmers don't have. State and Federal governments are talking about the problem, but they can't agree on a solution.