Macau, Asia’s foremost den of neon-soaked excess and sleazy glamour, has expanded to the brink of catastrophe and may be forced to ration drinking water as reservoirs run dry.

Indeed, to the horror of big casino operators, there are signs that non-essential supplies may be cut off as early as this weekend as authorities struggle to keep non-toxic water flowing through the taps.

Even the briefest spell without water would be a devastating blow to a hotel industry that has just installed thousands of luxury bathtubs and to a city whose GDP is derived almost entirely from opulence-hungry visitors.

Some forecasts suggest that Macau may have only ten days of fresh water left. Stocks of bottled water may have to be shipped in unless a deal can be struck with water companies in Guangdong province — suppliers who are already under intense strain to keep Hong Kong’s taps running as the water shortage takes hold.

Casino operators have not been told what to do as drought day approaches. A construction boom over the past four years has propelled Macau past Las Vegas to become the world’s biggest gambling centre and several of the newest resorts feature immense waterworks. The City of Dreams has a sprawling wave pool as its centrepiece, while the Venetian boasts three indoor canals and an outdoor lagoon sufficient to float 51 gondolas.

The looming crisis could not come at a worse time for the Macau unit of Las Vegas Sands, which plans to raise nearly $4 billion (£2.4 billion) through a listing on the Hong Kong Stock Exchange. The operator of the Venetian, credited with Macau’s transformation into a Vegas-style destination, was forced to halt construction on a colossal project last year as the credit crunch bit. The offering, being pitched to investors in London, will allow the company to resume building work.

Analysts at CLSA, a brokerage that covers Macau’s gaming industry, said that the government of the special administrative region — the other is Hong Kong — was likely to step in to do whatever was necessary to protect its main revenue source from drought.

But Macau’s usual water sources are in trouble. Reservoirs across the Chinese border in Zhuhai, which normally supply the gaming hub, have been ravaged by a drought that has affected a vast sweep of southern China and exposed the fragility of the country’s water system. Years of mismanagement have come back to haunt China, a country where pollution, illegal dumping, logging and mass urbanisation have left a deadly legacy for freshwater supplies.

Unlike Hong Kong, which struck a deal last year with Guandong province that would guarantee water supplies “even in a drought”, Macau has less visible contingency plans in place. Some MPs have said there are, in reality, none.

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