LCQ12: Water supply in Hong Kong

Following is a question by the Hon Frederick Fung Kin-kee and a written reply by the Secretary for Development, Mrs Carrie Lam, in the Legislative Council today (April 21):


In recent months, the south-western part of the Mainland, including Yunnan Province and Guangxi Zhuang Autonomous Region, etc., has been hit by a once-in-a-century severe drought, and the number of drought victims has exceeded 60 million.  Some mainland meteorologists have assessed that, against the background of global warming and the El Nino phenomenon, the severe drought is mainly attributed to the persistent weather of high temperature and low rainfall in the south-western part of China.  There have been comments that although the drought has not created immediate impact on the water source of the rivers in the Guangdong region, it has reflected the increasingly pronounced impact of climate change on human lives, which may exert pressure on local water resources in the long-term.  In this connection, will the Government inform this Council:

(a) whether it had, in the past five years, studied the possible impact of climate change and some medium to long-term climate phenomena, such as the El Nino phenomenon, on the water source of Dongjiang on the Mainland and the rainfall in Hong Kong, and formulated strategies in response to possible reduction in water resources in the future; if it had, of the outcome; if not, whether the authorities will conduct the study concerned;

(b) given that some 70% of the fresh water supply in Hong Kong relies on Dongjiang water at present and the remaining supply of some 20% mainly comes from surface water collected from local water gathering grounds, and although the current agreement for supply of Dongjiang water has ensured a reliable supply of fresh water in Hong Kong, there have been comments that under the impact of growing water demand created by rapid economic development on the Mainland and global warming, shortage in water resources is inevitable in the long-term, of the specific strategies of the authorities on water conservation, determination of water charges and development of new water resources; and

(c) given that the authorities have conducted studies on seawater desalination using reverse osmosis technology, and have confirmed the feasibility of adopting such technology locally, whether the authorities will make reference to the successful experience of Singapore and Australia and consider constructing desalination facilities using such technology in the medium to long-term, so as to provide more supply channels for water resources in the future and mitigate the risk of serious water shortage?



Currently the storage of our reservoirs is in a healthy position.  Coupled with the supply from Dongjiang, the community enjoys a reliable supply of potable water.  We expect that the water supply from Dongjiang under the current arrangement together with local sources is sufficient to cope with our demand for potable water up to year 2030.  Nevertheless, we must prepare for uncertainties such as climate changes and low rainfall, and enhance our role as a good partner of other municipalities in the Pearl River Delta region by doing our part in water conservation.

My reply to the three parts of the question of Hon Fung is as follows:

(a) The Government has conducted studies on the possible impact of climate changes and medium to long-term climate phenomena on the rainfall in Hong Kong.  We expect that, under the influence of global climate changes, the average annual rainfall in Hong Kong will rise in the latter half of the 21st century and the year-to-year variability in rainfall would also increase.  The number of days with heavy rains is also likely to increase in the 21st century.  For the latest detailed projections on the changes in rainfall in Hong Kong, please visit the website of Hong Kong Observatory.

The impact of climate changes on the supply of Dongjiang water to Hong Kong will be relatively minor as the supply only accounts for about 3% of the river's average annual flow volume.  That said, we will stay in touch with the Guangdong Provincial Government to ensure that the phenomena of climate changes will not undermine the reliability of water supply to Hong Kong.

In parallel, to meet the long term demand for potable water in Hong Kong and respond effectively to the future unpredictable changes, such as climate changes and low rainfall, the Government commenced a study on water resources management in 2005 and launched the Total Water Management Strategy in October 2008.  The Strategy puts emphasis on containing growth of water demand through conservation.

The key initiatives under the Strategy are as follows:

(i) Water Demand Management
- to enhance public education on water conservation
- to promote use of water saving devices
- to enhance water leakage control through the programme to replace and rehabilitate aged water mains, and application of new technology to improve pressure management and leakage detection
- to extend use of seawater for toilet flushing

(ii) Water Supply Management
- to strengthen protection of water resources
- to actively consider water reclamation (including re-use of grey water and rainwater harvesting)
- to develop the option of seawater desalination

(b) On water demand management, the Water Supplies Department (WSD) has focused for the past year on educating the public on water conservation and implementing the voluntary Water Efficiency Labelling Scheme (the Scheme) in phases.  Our efforts in public education include broadcasting promotional clips on television and radio, distributing leaflets, and organising seminars and exhibitions.  To raise students' awareness of water conservation, we have organised activities in primary schools so that students will better understand water saving knowledge.  To sustain their awareness, we also commend students who put what they have learnt into practice.  As for the Scheme, it provides information to consumers on the water consumption level and efficiency rating of plumbing fixtures and appliances to help them select water efficient products.  The aim is to promote water saving through enhancing the public's awareness of water conservation.  To date, 21 showerhead models have been registered under the Scheme on Showers for Bathing launched in the first phase.  We will extend the Scheme to cover water taps in 2010.  In addition, various water saving devices have been installed in 128 government buildings and schools by means of minor works projects.

On determination of water charges, the Government will, as usual, review regularly water charges according to the users pay principle.

On developing new water resources, the WSD has completed the pilot scheme on using reclaimed water in Ngong Ping and Shek Wu Hui.  The Department has confirmed that the scheme is technically feasible.  We have set up an inter-departmental working group to study how best we can lower the cost of producing reclaimed water in Shek Wu Hui Sewage Treatment Works, with a view to providing reclaimed water to consumers in Sheung Shui and Fanling for toilet flushing and other non-potable uses.  We have also introduced facilities for re-use of grey water and rainwater harvesting in some public works projects, such as Redevelopment of Lo Wu Correctional Institution and District Open Space at Po Kong Village Road, Wong Tai Sin.

Moreover, the WSD commenced in 2003 pilot tests on application of reverse osmosis technology in desalination in Tuen Mun and Ap Lei Chau.  The pilot tests, completed in 2007, confirm that the reverse osmosis desalination technology is technically viable for Hong Kong.  However, as the cost of desalination is much higher than Dongjiang water, vast investment in desalination is not cost-effective for the time being.

(c) Overseas experience including Singapore and Australia shows that desalination costs remain relatively high.  But we expect that advances in technology, such as improved efficiency in energy recovery systems and application of large diameter membrane in reverse osmosis process, will bring down the costs over time.  Therefore, we will continue to monitor closely the latest developments in desalination technology as a possible way to expand our sources of water supply in future.

Ends/Wednesday, April 21, 2010
Issued at HKT 14:51