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LCQ4: Water supply for Hong Kong

Following is a question by the Hon Dennis Kwok and a reply by the Acting Secretary for Development, Mr Eric Ma, in the Legislative Council today (November 12):


At present, Dongjiang water is the main source of fresh water for Hong Kong, meeting around 70% to 80% of the total water consumption in Hong Kong.  Yet, there are uncertainties in the supply of Dongjiang water, which include droughts occurring from time to time in some mainland provinces as a result of global climatic change, the significant increase in demand for water resources on the Mainland in recent years, as well as the potential impacts of urban development in cities along the Dongjiang River on the quality of Dongjiang water.  Meanwhile, the current agreement for the supply of Dongjiang water is due to expire at the end of this year, and the Government has reached another agreement with the Guangdong authorities for the supply of Dongjiang water in the next three years.  The new agreement will continue to adopt the "package deal lump sum" approach in the calculation of water price, i.e. a fixed amount of annual lump sum payment will be made to the Guangdong side for the supply of an annual agreed quantity of Dongjiang water to Hong Kong.  The annual increase in water price under the new agreement will be around 6%, and the lump sum to be paid over the three-year period will amount to $13.49 billion.  In this connection, will the Government inform this Council:

(1) of the unit price of Dongjiang water imported to Hong Kong in the past two years, as well as the unit price of Dongjiang water under the scenario of the quantity of water imported reaching the annual supply ceiling; whether it has assessed if the water price calculated according to the package deal lump sum approach can be reduced with a lower annual supply ceiling; if the assessment outcome is in the affirmative, of the Government's reasons for maintaining the annual supply ceiling in the new agreement at 820 million cubic metres; if such an assessment has not been conducted, the reasons for that;

(2) in addition to the several seawater flushing systems under construction and the desalination plant at Tseung Kwan O which is expected to commence operation in 2020, of the details of the other projects on water resources under study by the authorities; and

(3) as the Secretary for Development has advised that the authorities had studied various options such as expanding the reservoirs and interconnecting them, and the results showed that these options were not cost-effective as the cost involved would far exceed that of collecting rainwater and purchasing Dongjiang water at present, whether the Government can provide information on the relevant studies, including the names of the reservoirs studied, the scopes and estimated costs of the works projects, as well as the government department(s) responsible for the studies?



The natural fresh water resources in Hong Kong mainly come from rainfall.  But the yield collected from local catchment is inadequate to meet our needs.  The rainfall is also unstable.  Dongjiang water, which now provides about 70% to 80% of our fresh water supply, is able to fill the gap arising from the inadequate local yield.  Therefore, a reliable and stable Dongjiang water supply arrangement is essential to Hong Kong.

The Guangdong authorities promulgated the "Water Resources Distribution Plan in the Dongjiang River Basin of Guangdong Province" (Distribution Plan) in 2008 setting out the maximum amount of water that Shenzhen, respective cities in the Guangdong Province and Hong Kong can draw from Dongjiang.  Under the Distribution Plan, the annual quantity of Dongjiang water available for abstraction for water supply is 10 700 million cubic metres (mcm).   Hong Kong has been allocated an ultimate annual supply quantity of 1 100 mcm.   Taking into account the slower pace of growth of fresh water demand in Hong Kong, the annual supply ceiling in the current Dongjiang water supply agreement is 820 mcm.  The Guangdong authorities regulates the flow of Dongjiang by coordinating the flow control of the three major reservoirs (with a total storage capacity of 17 000 mcm) of Dongjiang and maintains a stable supply of water to Hong Kong.

The Guangdong authorities have been attaching great importance to the protection of Dongjiang water.  It has implemented a series of measures on prevention and control of water pollution to ensure that the quality of Dongjiang water supplied to Hong Kong complies with Type II waters in the Environmental Quality Standards for Surface Water (GB 3838-2002), which is the highest national standard for surface water applicable for the abstraction for human consumption, as specified in the supply agreement.  According to our water quality monitoring data, the quality of Dongjiang water supplied to Hong Kong has met this standard.

To meet the challenges arising from climate changes and competing demands for water resources in the Pearl River Delta region, we promulgated the Total Water Management (TWM) Strategy in 2008.  The TWM strategy seeks to manage the water demand and water supply in order to achieve an optimal balance in the supply and demand of water resources to support the sustainable development of Hong Kong.

My reply to the three parts of the question raised by the Hon Dennis Kwok is as follows:

(1) We have adopted the "package deal lump sum" approach in the Dongjiang water supply agreements since 2006.  Under this approach, we make a fixed annual lump sum payment to the Guangdong side in return for a guaranteed annual water supply up to the ceiling in the agreements.  The actual quantity of Dongjiang water imported can also be flexibly adjusted in accordance with the local yield of the year.  Under this approach, Hong Kong is assured of an adequate fresh water supply even under drought condition with a return period of one in 100 years.  We can also avoid importing Dongjiang water more than necessary in years of high yield, thereby avoiding wastage of water resources and saving pumping cost.  Therefore, a unit water price is not applicable under this approach.

The Water Supplies Department carries out detailed analysis based on fresh water demand forecast and estimates the supply ceiling during the agreement periods for 99% reliability of water supply.  Since the promulgation of the TWM Strategy in 2008, we have been implementing various water demand management initiatives to contain the growth of fresh water demand and reduce water loss.  The annual supply ceiling of Dongjiang water has therefore been maintained at 820 mcm since 2006.

If the annual supply ceiling is lowered, Hong Kong will be exposed to a risk of inadequate water supply in the event of drought.  In fact, over the past eight years when the package deal lump sum approach was adopted, Hong Kong needed to import Dongjiang water up to the ceiling in 2011 as the rainfall in that year fell short of the normal level by 40%.  If the annual supply ceiling of 820 mcm had been lowered, Hong Kong might have inadequate fresh water supply in 2011 and might need to impose water rationing, which would seriously affect people's livelihood and the economy.

(2) Apart from expanding the seawater flushing system and studying the construction of a desalination plant, the Water Supplies Department also plans to provide reclaimed water in the North East New Territories (NENT).  The department will also promote grey water reuse and rainwater harvesting.

As it is far from the seashore, the North New Territories mainly uses fresh water for flushing.  To support the developments in NENT, the capacity and treatment level of the Shek Wu Hui Sewage Treatment Works will be upgraded.  The Water Supplies Department plans to convert the tertiary treated effluent from the Shek Wu Hui Treatment Works into reclaimed water for supplying to the NENT New Development Areas, Sheung Shui and Fanling for flushing and non-potable uses.  It is anticipated that reclaimed water will be supplied to the residents of Sheung Shui and Fanling by 2022.

In addition, the Water Supplies Department is also formulating guidelines on introducing facilities for grey water reuse and rainwater harvesting in appropriate new government projects.  We will also encourage developers to adopt such facilities.

(3) The Secretary for Development remarked in his blog article entitled "Water management strategy responds to climate change" that the Administration had considered various options, including expanding the reservoirs and interconnecting them, with a view to minimising the amount of overflow from the reservoirs.  However, the assessments showed that such options were not cost-effective, as the investment and operational cost to further reduce overflow would far exceed the cost of collecting rainwater or even the purchase cost of Dongjiang water.

The overflow from local reservoirs has been significantly reduced since the adoption of the "package deal lump sum" approach in 2006.  At present, overflow only occurs in small and medium-sized reservoirs.  Their scope for expansion is limited by the terrains.  Indeed, any expansion may affect the surrounding environment, ecology and nearby facilities.  The dams and water supply facilities of some of these reservoirs have also been designated declared monuments.  With regard to the option of interconnecting the reservoirs, it would entail works of very large scale and high costs as they are very far from large reservoirs.

According to the rough estimates of the Water Supplies Department, the unit cost for expanding or interconnecting reservoirs to reduce overflow would be over HK$20 per cubic metre, far exceeding the current costs of collecting rainwater or even the purchase cost of Dongjiang water.  It should be noted that the estimates have not yet taken into the account the costs for implementing necessary measures to mitigate the environmental impact of the works and reprovisioning of affected infrastructures.

Increasing local water storage will require increasing the area of the local catchment and expanding reservoirs.  At present, the local catchment measures 300 square kilometers, accounting for about 30% of the total area of Hong Kong.  There is a serious shortage of developable land in Hong Kong.  Besides, developments within the catchment are subject to stringent restrictions.  In consideration of land resources and the impact on the environment and nearby facilities, it is not viable to identify suitable land in Hong Kong for expanding the catchment or constructing large new reservoirs.

Ends/Wednesday, November 12, 2014
Issued at HKT 15:15