A labourer works on the Danjiangkou dam, under construction for the middle route of the South-to-North Water Diversion Project, in central China's Hubei province in this August 17, 2007 file photo. As liquidity is drained from credit and money markets and pours into oil and gold, another asset class that could offer longer-term returns to the discerning investor is water. To match feature WATER-TECHNOLOGY REUTERS/Stringer/Files (CHINA) CHINA OUT
REUTERS/STRINGER SHANGHAI