Water is similar to what oil is or once was -- undervalued and taken for granted, and consumers could soon pay a real price for it. Analysts say increased demand for clean water has been driving up the cost, bad news for a world already concerned about rising food prices. Agriculture is the world's top water user, accounting for an estimated 70% of total global consumption. The world's scarcity of clean water is widely known, yet it's still one of the cheapest commodities in the world. Municipal water rates have climbed by an average of 58% in Canada, 50% in South Africa, and 27% in the U.S., according to an Earth Policy Institute report issued last year. In a survey of 14 countries, average municipal water prices ranged from 66 cents per cubic meter in the U.S. up to $2.25 in Demark and Germany, it said. Demand for corn to create ethanol has helped lift corn prices to their highest levels ever. "Demand for corn at ethanol plants is huge, but demand for water for ethanol plants is even bigger," said Kerr, who is also president of Kerr Trading International. Ethanol is very water intensive, said Mayer.So droughts can reduce the global harvest and the water crisis can "naturally feed inflation," said MoneyandMarket.com's Brodrick. "As water prices rise, there is a mighty river of profits, just waiting to be tapped," said Brodrick. As water is becoming a critical resource throughout the world, it is also turning into a commodity that can be traded. A sure sign of it is the slow emergence of water hedge funds. Buying stock in companies that make bottled water is a good option. And there are water exchange-traded funds, such as PowerShares Water Resources Portfolio , which hold a basket of stocks of companies involved in the production, treatment and distribution of water, said Brodrick.   more »