Tourists watch a demonstration of how the Marina Barrage dam works at a gallery in the Marina Barrage facility in Singapore in this May 29, 2013 file photo. Fifty years ago, Singapore was rationing ... more 
Tourists watch a demonstration of how the Marina Barrage dam works at a gallery in the Marina Barrage facility in Singapore in this May 29, 2013 file photo. Fifty years ago, Singapore was rationing water and struggling with smelly rivers devoid of fish and choked with waste from shipbuilding, pig and duck farms, and toilets that emptied directly into the streams. At that time, the 700 sq km island nation relied on three protected reservoirs and water imported from neighbouring Malaysia. Today, Singapore collects rainwater from two-thirds of its land through an 8,000-km drain network into 17 reservoirs; reclaims "used water" from a deep tunnel sewerage system up to 60 m below ground; and is developing technology to halve the energy used to desalinate seawater. REUTERS/Edgar Su/Files less 
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Reuters | Photo By EDGAR SU / REUTERS
Sun, Aug 2, 2015 9:58 PM EDT