Fifteen years ago, the Water Supplies Department (WSD) launched a large-scale water mains programme to replace and rehabilitate some 3 000 kilometres of aged water mains in phases. Most of these water mains were laid more than 30 years ago and their expiry dates are now looming. As a result, repair and maintenance works are getting more difficult and expensive. By March this year, 92 per cent of the works had been completed. The programme is expected to be substantially completed by the end of this year, and by then the condition of our water supply networks will be significantly improved.
The programme has effectively reduced water mains bursts and leakage rates. The number of water mains bursts was reduced from about 2 500 per year in 2000 to about 170 in 2014, while the leakage rate has also been reduced from a peak of 25 per cent to just 16 per cent in 2014. It is expected that upon completion of the programme, the leakage rate will be further reduced to 15 per cent, and there is room for the rate to go down further.
The completion of the replacement and rehabilitation of some 3 000 kilometres of aged water mains by the end of this year does not mean that our work ends there. We understand that water mains leakages and bursts cause significant inconvenience to the community. However, replacing and rehabilitating water mains to maintain the healthy condition of our water mains network is no longer the most cost-effective option.
One of the new initiatives proposed in this year’s Policy Address and Budget Speech is to study and establish the Water Intelligent Network (WIN). With advancements in sensor and data analysis technology in recent years, we can “keep our finger on the pulse” of our water mains by installing sensors in the underground water supply network to collect data and to establish district metering areas. An intelligent network management system will be put in place to monitor water mains leakage and supply data. We will also examine other techniques, such as data mining, to predict water mains bursts for early identification and handling of defective water mains.
In fact, many countries and cities including Israel, Manila and Lisbon have established intelligent network management systems and district metering areas to manage water mains networks and to deal with the leakage problem, and have achieved remarkable results.
The WSD plans to progressively implement WIN, which will involve the division of the territory into some 2 000 district metering areas (including 650 existing district metering areas). Installing sensors in the water supply network is like carrying out “minimally invasive surgery”, where small-scale excavations will be carried out on the road surface to find the right water mains for installing sensors. Compared with the replacement of water mains, which involves the excavation of the entire road section, WIN requires only limited excavation, which will minimise the inconvenience caused to road users and the community. The WSD is collaborating with relevant solution providers and equipment vendors to implement studies and tests in phases. Upon the completion of the related work, we can set a timetable for the full implementation of WIN.
Water is not only the source of life and a daily necessity, but also a crucial element to our future sustainable development. Continuous population growth and increasing economic activity, combined with the effects of climate change, present huge challenges in the context of the world’s limited water resources. We must therefore take precautionary steps to reduce the loss of our water resources.
12 April, 2015
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