Traditional Chinese Simplified Chinese Email this article
LCQ20: Fresh water supply

     Following is a question by the Hon Paul Tse and a written reply by the Secretary for Development, Mr Paul Chan, in the Legislative Council today (February 27):


     It has been reported that, at the first session of the 11th Guangdong Provincial Committee of the Chinese People's Political Consultative Conference (CPPCC), a member said that "if not for the Communist Party, Hong Kong [people] would not even have potable water to drink". This remark has drawn quite a number of reactions. Regarding the supply of Dongjiang water to Hong Kong and water supply in Hong Kong, will the Government inform this Council:

(a) in light of the remark of the aforesaid CPPCC member, whether the Government has studied any policies on and measures for raising the degree of autonomy in the supply of potable water in Hong Kong; if it has, of the outcome; if not, whether it can conduct such a study immediately;

(b) of the percentage of Dongjiang water in the total quantity of water supply in Hong Kong in the next five years; as it has been reported that the quality of Dongjiang water has deteriorated in recent years and there has been an annual increase of about 5.8% in its price, whether it has studied if the long-term reliance on Dongjiang water as the main source of potable water is cost-effective; as well as the latest progress in the search for other sources of potable water;

(c) whether it has studied the cost-effectiveness of the desalination facilities in Singapore (including the production cost of potable water); if it has, of the details;

(d) of the expected annual production capacity of the desalination plant planned to be built in Tseung Kwan O, the cost per cubic metre (m3) of potable water produced by that plant, and how such cost compares with the price of Dongjiang water;

(e) whether it has assessed, with the continuous improvement in desalination technology, if the gap between the cost of potable water produced by desalination and the price of Dongjiang water is narrowing, and if the former may become even lower than the latter; if it has assessed, of the respective price/cost per m3 of both types of water; if not, whether it will conduct such an assessment immediately;

(f) whether the quantity of Dongjiang water supplied to Hong Kong was higher than the water consumption of Hong Kong in the past three years; of the situation projected for the next three years, and whether there is room for reducing the quantity of Dongjiang water to be purchased and for reducing the expenses on purchase of water; how the authorities will strive for reducing the quantity of water supply and the price of water; and

(g) of the quantity of potable water lost/wasted due to leakage of water from worn-out water mains in each of the past five years; of the equivalent amount of public expenditure incurred by such loss/wastage of potable water as calculated at the current cost of water supply?



     Hong Kong does not have any natural lake, river or rich underground water resources. It also lacks reliable and evenly distributed rainfall. Therefore, it is a great challenge to develop a reliable and adequate source of water supply that can keep pace with the continual development of this city. Since the mid-19th century, Hong Kong has started building reservoirs to store rainwater for use of its people. At the end of the 1950s, Hong Kong started using seawater for flushing purpose to reduce potable water consumption. Since the 1960s, Hong Kong began to import raw water from Guangdong Province to meet the growing demand.  At present, rainwater collected locally can only provide 20% to 30% of the water demand in Hong Kong. The remaining demand of about 70% to 80% has to be imported from Dongjiang of Guangdong Province. To prepare for future uncertainties and to enable the sustainable development of Hong Kong, the Water Supplies Department (WSD) launched the Total Water Management Strategy (the Strategy) in 2008.  The Strategy mainly comprises two parts, namely: (1) water demand management and (2) water supply management. Its objective is to achieve an optimal balance between demand and supply to ensure sustainable and effective use of water resources.

      My reply to the seven parts of the question is as follows:

(a) The Government has been working on the policies and initiatives for Hong Kong's potable water supply and has rolled out diversified water supply management measures under the Strategy, including developing seawater desalination and studying water reclamation, greywater recycling and rainwater harvesting.

(b) We expect that the percentage of Dongjiang water in the total quantity of water supply in Hong Kong, i.e. about 70% - 80%, will remain unchanged in the next five years.

     In regard to water quality, the current Dongjiang Water Supply Agreement signed with the Guangdong Authorities provides that the quality of Dongjiang water supplied to Hong Kong should comply with the national standard for Type II waters (applicable for the abstraction for human consumption in first class protection area) in the "Environmental Quality Standards for Surface Water GB3838-2002". The Guangdong Authorities have always attached great importance to protecting the quality of Dongjiang water. Apart from formulating and implementing laws and regulations for the prevention and control of pollution to water resources, the Guangdong Authorities have also proactively undertaken a series of preventive and control measures, and works to ensure that the quality of Dongjiang water supplied to Hong Kong complies with relevant standards.

     The WSD has been closely monitoring the quality of Dongjiang water. Through its on-line water quality monitoring system at Muk Wu Pumping Station, the WSD monitors the quality of Dongjiang water supplied to Hong Kong round the clock. The WSD also regularly takes samples of Dongjiang water from Muk Wu Pumping Station and different water treatment works for analysing various pollution-related parameters. The findings of the WSD's regular water quality monitoring work in the past years show that the Dongjiang water supplied to Hong Kong is of consistently good quality and their indicative values are in compliance with the national standard.

     All raw water, including Dongjiang water, undergoes suitable treatment and rigorous purification processes at WSD's water treatment works to remove impurities in water. This ensures that drinking water supplied to the public is clean, hygienic and free from pathogenic bacteria. The treated drinking water is in full compliance with the requirements stipulated in the World Health Organization's Guidelines for Drinking-water Quality and is safe for consumption.

     On developing alternative sources of drinking water, the Government is, as mentioned above, in the course of implementing water supply management measures.  They include developing seawater desalination and studying water reclamation, greywater recycling and rainwater harvesting. Apart from locally collected rainwater, Dongjiang water remains the most economic water resources available to Hong Kong at present.

(c) We have made reference to overseas experience in desalination facilities in various countries, including the United States, Australia and Singapore. Given their different calculation methods for energy charges, the production costs of desalinated water cannot be compared directly. Notwithstanding this, their data on energy consumption and other operational parameters provide useful reference and have been used for projecting the cost of producing fresh water in the on-going planning and investigation study for the proposed desalination plant at Tseung Kwan O.

(d) When commissioned, the proposed desalination plant at Tseung Kwan O Area 137 will have an estimated annual production capacity of about 50 million cubic metres (and expandable to about 90 million cubic metres in future). The estimated cost of its fresh water supply is about $12 per cubic metre at current price level. The current cost for Dongjiang water supply is about $8 per cubic metre.

(e) Reverse osmosis technology is a relatively sophisticated desalination method. The operating cost of this technology mainly comprises electricity charges and the costs for membrane replacement and chemicals. Compared with other resources, the reverse osmosis desalination process consumes more energy and entails a higher production cost. With the local electricity tariff on the upward trend, the cost of desalination will not drop to a level comparable to Dongjiang water in the short run.

     In 2012, the WSD engaged consultants to carry out a two-year planning and investigation study on the proposed desalination plant at Tseung Kwan O in order to examine in detail the feasibility and cost effectiveness of the plant and associated fresh water transfer facilities. The consultants will conduct detailed studies and assessment for different construction proposals, desalination technology, energy consumption, construction cost and cost effectiveness.

(f) Table 1 below sets out the actual water consumption of Hong Kong and the actual quantity of Dongjiang water supplied to Hong Kong from 2010 to 2012. It shows that the annual supply of Dongjiang water over the past three years is less than the actual consumption, accounting for 73% to 89% of the total consumption. We expect that the situations will maintain at a similar level in the coming three years.

Table 1: Actual water consumption of Hong Kong and
         the quantity of Dongjiang water supplied
         from 2010 to 2012
                     Actual supply
       Actual water  of Dongjiang   Percentage of
       consumption   water to       Dongjiang water
       of Hong Kong  Hong Kong      to actual Water
       (million      (million       consumption in
       Cubic         cubic          Hong Kong
Year   metres)       metres)        (%)
----   ------------  -------------  ---------------
2010       936           681             73
2011       923           818             89
2012       935           709             76

     As mentioned above, we have strived to contain the growth of fresh water demand by implementing various water demand management initiatives under the Strategy in 2008.  Despite the steady growth in Hong Kong's population, we have achieved progress in water conservation through public education, promotion on the use of water saving devices and measure to replace and rehabilitate aged water mains to reduce leakage over the past few years. Under the current Agreement, the annual supply ceiling of Dongjiang water is set at 820 million cubic metres, which is sufficient to meet our actual needs and ensure 99% reliability of water supply for the next three years. We can be assured of continuous water supply round the clock even under the extreme drought conditions with a return period of 1 in 100 years.

     On the price of Dongjiang water, the Dongjiang Water Supply Agreement signed with the Guangdong Authorities provides that the price adjustment should be based on operation costs, having regard to the relevant price indices of both parties as well as the exchange rate between Renminbi and Hong Kong dollar. As such, the price adjustment of Dongjiang water basically reflects changes in these factors.  We consider the adjustments reasonable.

(g) The water main leakage rate from 2008 to 2012 is set out at Table 2 below.

Table 2: Water main leakage rate from 2008 to 2012
Year    Water main leakage rate (%)
----    ---------------------------
2008              21.8
2009              21
2010              20
2011              19
2012              18

     Given the highly varying terrain of Hong Kong, service reservoirs located on high altitude have to supply water to premises at different levels. As a result, water mains at lower altitudes operate under relatively high water pressure, making them more susceptible to leakage. Therefore, water main leakage should be considered an operational constraint instead of loss. We will continue our water main replacement and rehabilitation works, and strengthen pressure management and leakage detection to minimise water main leakage throughout the territory. Indeed, the leakage rate has dropped from 25% in 2001 to 18% in 2012 after the adoption of these measures.

Ends/Wednesday, February 27, 2013
Issued at HKT 15:21


Print this page