HK$9b plan to keep Hong Kong taps running in a drought

A HK$9.3 billion project to convert seawater into tap water is being rolled out to offset the risk of a severe drought in the Pearl River Delta drying up the city's main water source - Guangdong's East River, or Dongjiang.

A 10-hectare site on Joss House Bay, southeast of Tseung Kwan O, has been earmarked for the desalination plant. After completion of a first stage in 2020, it would be able to meet about five per cent of Hong Kong's needs - some 135,000 cubic metres of water a day. Eventually that output could be doubled.

In normal conditions, the plant could be used to serve the Tseung Kwan O district.

The cost of producing a cubic metre of fresh water at the new plant has been estimated at HK$12 to HK$13. In contrast, importing water from Guangdong costs HK$8.6 per cubic metre.

Officials maintained it was too early to say whether the project could lead to higher water bills for Hongkongers, adding that "ability to pay" would be taken into account in any discussion on tariff changes.

The Development Bureau will be seeking legislators' approval for a funding request of HK$154.6 million for initial design costs and site investigations, and officials are expected to brief lawmakers on the project at a Legislative Council development panel meeting next Tuesday.

Hong Kong consumed more than 930 million cubic metres of fresh water in 2013, and as much as 80 per cent of that is imported from the East River.

A bureau spokesman said Hong Kong had been facing keener competition for the East River's water resources because of the rapid economic development in the Pearl River Delta region.

"In case of severe drought, it is possible that the water available in the East River may not be able to meet the water demand of Hong Kong after 2020. To safeguard water security in Hong Kong, we need to develop the alternative water resource by seawater desalination."

During a prolonged drought in Guangdong in 2009, Hong Kong considered temporarily reducing its water intake from the province.

Hong Kong operated a desalination plant in the 1970s, in Lok On Pai, Tuen Mun. But the oil-fuelled plant was shut down in 1982, seven years after it came into use, because of high operating costs. The plant was eventually demolished in 1991.

The bureau spokesman said the new desalination plant would adopt modern-day treatment technology of reverse osmosis, which is used in many parts of the world. "With technology advancing, we expect the operating costs to remain stable or even decrease in the long run," the spokesman added.

According to the International Desalination Association, there are more than 17,000 desalination plants worldwide, capable of producing a total of more than 80 million cubic metres of fresh water every day.

The biggest desalination plant in the world is in Israel, where some 80 per cent of the water is recycled and reused.

At Tuesday's meeting, the bureau is also expected to consult legislators on a HK$823.4 million project to construct a new regional office in Tin Shui Wai, Yuen Long, for the Water Supplies Department.

The present office, in Mong Kok, will be vacated in 2018 to make way for redevelopment of the prime site.