LCQ4: Loss of water due to water mains leakage
Following is a question by the Dr Hon Helena Wong and a reply by the Secretary for Development, Mr Michael Wong, in the Legislative Council today (February 7):
The Government spends a huge amount of public money each year on the supply of fresh water to members of the public, with the purchase of Dongjiang water from the Mainland alone costing approximately $4.8 billion a year. However, according to the information for the period from 2006 to 2015, the rate of water loss persistently stood at over 30 per cent. The causes of water loss include leakage from public mains and from the water mains within the areas of some private residences. In this connection, will the Government inform this Council:
(1) of the district, among the 18 District Council districts across the territory, in which the problem of public mains leakage is most serious at present, and set out in a table the water leakage rate of each district in the past three years;
(2) as it has been reported that water mains leakage has been a long-standing problem in certain large-scale housing courts, in which an estimated quantity of 30 per cent of fresh water is lost before the water is delivered to and recorded by the meters of various customers, regarding public rental housing estates, Home Ownership Scheme courts and private housing courts, of the respective names of the 30 housing estates or courts with the highest water loss rates in the past three years, as well as their annual total quantities of water loss and the loss of public money thus incurred; and
(3) of the Government's measures to lower Hong Kong's water leakage rate and water loss rate, as well as the implementation timetable for and the objectives and other details of such measures?
Given the hilly terrain of Hong Kong, the water pressure of our water supply networks is generally higher than that of other cities. Together with vibration and disturbance caused by busy traffic and frequent roadworks, these factors cause an increase in the risk of water mains bursts and leakage, making it a great challenge to manage the leakage problem in the water supply networks in Hong Kong.
The "rate of water loss" of over 30 per cent mentioned in the question should mean the "unmetered consumption". Taking 2016 as an example, "unmetered consumption" made up about 33 per cent of total water consumption, of which about 6 per cent was water used for firefighting and operation of waterworks (such as water used in water treatment works, washing service reservoirs and flushing government water mains, augmentation of salt water flushing systems during their maintenance, temporary water supply due to emergency repairs, etc.), and about 2 per cent was attributed to the recording of a lower water usage because of aging water meters. Water loss due to leakage in government water mains was about 15 per cent, with the remaining amount attributed to leakage in private water mains and unlawful taking of water.
My consolidated response to the three parts of Dr Hon Helena Wong's question is as follows:
For government water mains, in the 1990s, as a substantial portion of government water mains were reaching the end of their service life, their maintenance became increasingly difficult and costly. In 2000, the annual number of water main burst incidents rose to about 2 500 cases, and the leakage rate had exceeded 25 per cent. Replacement and rehabilitation of water mains was the most effective solution to stop the rapid increase in water main bursts and leakages. Therefore, since 2000, we launched the Replacement and Rehabilitation Programme of Water Mains (the Programme) to replace and rehabilitate about 3 000 kilometres of aged water mains.
Following the substantial completion of the Programme in 2015, the condition of the government water supply networks has improved significantly. The annual number of water main burst incidents dropped drastically to about 90 in 2017, and the leakage rate also dropped to about 15 per cent. According to a study report published by the Organisation for Economic Co-operation and Development in 2016, when compared to other developed countries and cities, Hong Kong currently ranks in the middle range in terms of leakage rate. Our leakage rate is lower than that of Montreal of Canada, Rome of Italy, and Liverpool and Edinburgh of the United Kingdom; but higher than that of Singapore, New York of the United States and Paris of France. The leakage rates of the above countries and cities range from around 5 per cent to 32 per cent.
Riding on technological advancement, as well as an overall improvement in the government water supply networks, implementing a Water Intelligent Network (WIN) is considered a more cost-effective measure than continuing to implement large-scale replacement and rehabilitation of water mains. Therefore, we are actively pursuing the building up of WIN by stages. Under WIN, we collect data from the water supply networks by establishing District Metering Areas (DMAs). Furthermore, we will soon procure the Intelligent Network Management System to continuously monitor, and analyse the vast amount of network data collected from DMAs. WIN enables us to timely determine any abnormal condition in the water supply networks. We can then implement the most appropriate network management measures and set the most appropriate working priorities accordingly, thus further enhancing the condition of the water supply networks and reducing leakages.
The Finance Committee (FC) of the Legislative Council approved the funding for the construction of WIN Stage 1 in June 2016. We are also planning to seek funding approval from the FC for WIN Stage 2 later this year. The entire WIN is targeted to be completed in 2023. Although WIN is still under construction, we have already taken actions on water mains with suspected leakages based on data collected from individual DMAs that have been established. For example, last year there was a case of suspected leakage in water mains as abnormal data was recorded in a DMA in Kwei Chow Street of To Kwa Wan. We carried out detection and identified the water mains with leakage for repair. The water loss situation in the DMA had improved after maintenance.
As for leakages in private water mains, according to the Waterworks Ordinance, it is the responsibility of the registered agents (usually management companies) to repair any leakage in the communal water mains in housing courts or estates. In the Policy Agenda published in October 2017, the Government has elaborated on measures targeting leakages in private water mains. We will take forward the following measures to assist property owners and registered agents on leak detection and maintenance of water mains, including:
(1) through various channels, including holding briefings, to raise the awareness of property owners and registered agents on detecting leakages and maintaining water mains within their housing courts or estates proactively;
(2) provide a reference list of local service providers of leak detection;
(3) publish a guideline on leak detection and maintenance of private water mains; and
(4) assist the development of a market in leak detection and maintenance of water mains, so a professional and competitive leak detection and maintenance service can be provided to property owners and registered agents.
Furthermore, we have been installing master meters for private housing courts or estates to monitor water losses in their communal mains and will follow up on cases with suspected leakages in the communal water mains. We will step up enforcement actions in accordance with the Waterworks Ordinance if we encounter any uncooperative property owners or registered agents. We hope that through the above measures, the leakage rate at private water mains can be continuously improved. We will also explore imposing water charges on property owners or registered agents according to the amount of water loss from their communal water mains based on the master meters through legislative amendments.
In addition, to reduce other "unmetered consumption" such as unlawful taking of water and inaccuracy of water meters, we will step up enforcement actions and replace aged water meters regularly. The Government targets to reduce leakage rate in government water mains to below 10 per cent by 2030.
Since WIN is still under construction, and master meters are not yet installed in all private housing courts or estates, we are not able to provide a public mains leakage data of the 18 Districts across the territory, nor the names of 30 housing courts or estates with the highest water loss rates. Besides, as the related data fluctuates due to follow up actions taken by the Government and individual housing courts or estates, or changes in their internal situations (such as water usage, water pressure or leakage situations), it would not be desirable to list out the data for an overall comparison of leakage situation. Also, the Government has to assess whether the release of such data can achieve the objective of the water conservation policy effectively, and carefully consider if the release of the data would induce unnecessary pressure on the households concerned.
Ends/Wednesday, February 7, 2018
Issued at HKT 17:05