Project succeeds in lifting Dongjiang water quality

The Dongjiang, the Guangdong river that supplies most of Hong Kong's fresh water, is significantly cleaner now than in the past, an inspection has found.

An advisory committee that conducted the study attributed the change to a water improvement project commissioned by the Hong Kong and provincial governments in 2003.

"The clarity of the water and lack of smell shows that water quality is much better than it was in the past," said Chan Hon-fai, chairman of the Water Supplies Department's advisory committee on water resources and quality of water supplies.

"There was also no industrial waste or pollution that we could see," Chan said.

The river was once regarded as one of the most polluted in the world. But Chan said signs like the presence of freshwater peach blossom jellyfish in the river showed it was much cleaner.

Known in English as the East River, it supplies about 80 per cent of Hong Kong's fresh water, while providing drinking water to 40 million people in the Pearl River Delta.

In 2010, the delta city of Dongguan found only half of 114 water samples taken from the Dongjiang met national drinking water standards.

Hong Kong imported 800 million cubic metres of water costing HK$3.9 billion from the Dongjiang this year, according to the Water Supplies Department.

Despite the improvement, a department official says Hong Kong needs to look for alternative water sources because of a population surge in the region and the possibility of more droughts.

"Climate change may bring about more droughts," assistant director for development Vincent Mak Shing-cheung said. "We should re-examine our consumption habits and look at backup water sources in the form of desalinated water or recycled wastewater."

Mak said a proposed seawater desalination plant in Tseung Kwan O could be ready by 2020.