No room for lower limit on Hong Kong water supply from mainland China river, expert says
Adviser says 820 million cubic metre ceiling must stay to ensure adequate supply, despite full amount rarely being used by city’s residents
Hong Kong should not seek to lower its water supply ceiling from the Dongjiang to ensure adequate provision in emergencies and extreme weather events, the head of a government advisory committee said on Wednesday.
But Dr Chan Hon-fai, who chairs the Advisory Committee on Water Supplies, declined to comment on whether the city was getting a fair deal on the fixed annual supply agreement signed with Guangdong province, or whether it should be revised to a pay-as-you-go arrangement.
“In the past, there were occurrences where we really did reach that ceiling, so this 820 million cubic metre limit cannot be lowered,” he said. “We must ensure the security of our water supply.”
The Dongjiang – or East River – supplies Hong Kong with 70 to 80 per cent of its consumption needs.
The government revealed this week that the new agreement with Guangdong for 2018 to 2020 would retain a guaranteed annual supply ceiling of 820 million cubic metres of water for a lump sum of HK$14.4 billion, about 7 per cent more expensive than the previous 2015-17 deal.
The “package deal lump sum” arrangement has been used since 2006 despite Hong Kong rarely ever getting to the ceiling. Critics have called for a more flexible deal in which the city pays for the volume consumed. The Development Bureau says the arrangement could be reviewed after 2020.
Chan stressed that with increasing freshwater demand in the Dongjiang basin and the risks of extreme weather events such as droughts and floods, which could affect flows, water resources would become increasingly tight and that there was a need to reduce dependence.
“We can anticipate that in the coming years ... more cities in the Guangdong area will also be demanding water from the Dongjiang,” he said. “By expanding sources [locally], we hope that we can cut down on our demand and reliance on the Dongjiang.”
The Water Supplies Department is already exploring or pursuing sources such as desalination and reuse of grey water in addition to traditional means such as reservoirs and using seawater for flushing.
Chan was speaking after an annual committee inspection of the Dongjiang’s mid to downstream section, in which the advisers found the visible water quality to be “very satisfactory”.
But the committee said the biggest weakness was still polluted stormwater from Shenzhen’s Shawan River entering the Shenzhen Reservoir, the end point of the river system, which feeds into Hong Kong’s dedicated supply.
“To be honest, the Shawan River still smells,” Chan said.
But the committee expected improvements with the completion of a system in July 2019 where polluted water from the Shawan River will be diverted to a treatment plant.