City's thirst for groundwater threatens ancient temples

SIEM REAP, Cambodia: The five-star hotels around the ancient temples of Angkor are oases of green - sleek new buildings ringed by tropical forests and sprawling lawns.

But the water used to keep them so is being sucked from groundwater under the nearby city of Siem Reap, threatening the stability of the centuries-old World Heritage-listed landmark.

The widespread, unregulated pumping of groundwater throughout Siem Reap has raised concerns that the temples, including the world's largest religious monument, Angkor Wat, could crack or crumble if too much water is drained away.

The temples and towers of the 400-square-kilometre Angkor site sit on a base of sand, kept firm by a constant supply of groundwater that rises and falls with the seasons, but which is now being used to supply a burgeoning city.

With the number of visitors approaching 2 million a year, increasing pressure is being put on the scarce water resource. Thousands of illegal private pumps have been sunk across the city, pulling millions of litres of water from the ground each day.

UNESCO, the cultural arm of the United Nations, says that no one knows just how much water is being drawn from the ground, or how much can be taken safely.

Water is a precious commodity in Siem Reap, particularly during the dry season, when tourist numbers are highest. And the population of the city, barely five kilometres from Angkor Wat, has doubled in a little more than a decade to about 200,000.

The government-run Siem Reap water supply authority has the capacity to pump nine megalitres of water a day from underground, its director general, Som Kunthea, said.

But Mr Som estimates the city, even at its current size, is already using more than 50 megalitres daily. Authorities believe there are more than 6000 private pumps and 1000 wells sunk across the city.

The deputy director of water management for the Cambodian government's Angkor conservation body, Peou Hang, said the pumping was unregulated and almost impossible to police.

The Cambodian government has commissioned the Japanese government development agency JICA to investigate future water options for Siem Reap.

Its report, now in draft stage and to be completed by the end of the year, is likely to recommend regulating the pumping of groundwater as well as bringing water from other sources, including Tonle Sap, a lake 20 kilometres south of Siem Reap, an option that Mr Som would ''cost a lot and make water more expensive''.

Mr Som said the government's water authority does not have the capacity to supply all of Siem Reap with drinking water.

''Right now, there is no sign of impact on the temples,'' he said. ''But if we don't move now … if we keep letting people pump water and the population continues to increase, it will have an impact.''