Sustainability Report

For more than two decades, the flood prevention and sewage treatment facilities of the Drainage Services Department (DSD) have been silently supporting the livelihood of citizens and the development of Hong Kong. It is my pleasure to share the good progress achieved in various projects of DSD in the year 2016-17. Among these, two of particular significance, namely the Happy Valley Underground Stormwater Storage Scheme (HVUSSS) and the Hong Kong's largest Solar Farm at the Siu Ho Wan Sewage Treatment Works (SHWSTW), were commissioned during the year. These two projects demonstrate our determination to strengthen the flood prevention capacity of Hong Kong and to develop renewable energy. However, revisiting the extreme weather situation in 2016, I, like you, can truly appreciate the severe challenges that climate change had inflicted upon Hong Kong. Therefore, we cannot be complacent, but need to heighten our vigilance at all times and put more efforts in our work of adaptation to (by taking forward flood prevention projects) and mitigation of (by developing renewable energy) climate change.

Flood Prevention in Rainy Season

According to the assessment by the World Meteorological Organization, 2016 was likely the warmest year on record in the world. The annual rainfall in Hong Kong was up to 3,027mm, about 26% higher than the Climate Normal. Due to the frequent occurrence of extreme weather, there is a pressing need to optimise our flood prevention facilities across the board. Over the past two decades or so, we have eliminated more than 120 flooding blackspots. In early 2017, we eliminated one more, further reducing the number of flooding blackspots in the territory to seven. Besides, flood prevention works costing about $12.6 billion are currently under planning, design and construction. Among them are the Kai Tak River Improvement Works and Shenzhen River Regulation Project Stage IV, both of which are in progress.

Sponge City

In recent years, DSD has actively incorporated the concept of “Blue-Green Infrastructure” into various projects. While enhancing the flood prevention capacity, we place emphasis on protecting the ecological value of the surrounding environment and seize the opportunities to promote biodiversity as well as water-friendly culture. Meanwhile, we have introduced the “Sponge City” concept of “following the nature with resilience” to a number of projects in order to divert stormwater through natural means, such as infiltration, flood storage and retention, to avoid undertaking large-scale drainage works. Among these, the HVUSSS, which has a total storage capacity of 60,000 cubic metres and was fully commissioned just earlier this year, sets an obvious example of implementing the “Sponge City” concept in Hong Kong. Various innovative elements, including “smart” (i.e. movable) weirs, water harvesting system, and land co-use design, were incorporated in the HVUSSS.

New Engineering Contract

The HVUSSS is also a successful example in adopting the “New Engineering Contract” (NEC), which has provided a solid foundation and valuable experience for future public works projects. NEC stresses a partnering relationship with mutual trust and co-operation, team spirit as well as pain-gain share mechanism. With the concerted effort of the project team, the works were completed a year in advance, resulting in a saving of construction cost by approximately $90 million. The HVUSSS project is highly commended within and outside the Department, which was attributed to the project team's strong commitment and innovative spirit, coupled with its close liaison and sincere cooperation with stakeholders.

Sewage Treatment

In view of the continuous development and population growth in various districts in Hong Kong, DSD needs to upgrade the drainage facilities in good time to cope with future needs. During the reporting period, we commenced the upgrading of San Wai Sewage Treatment Works Phase 1 to increase the capacity of the plant to 200,000 cubic metres per day while upgrading its treatment level to chemically enhanced primary treatment. Besides, to make the sewerage system more reliable, we have commenced the construction of a sewage rising main of 6.5km long with a diameter of 1.2m from Tung Chung to Siu Ho Wan. Furthermore, we will continue the active study on the relocation of sewage treatment works to caverns and strive for the early commencement of the advance works for the relocation of Sha Tin Sewage Treatment Works to caverns.

Renewable Energy

As sewage treatment facilities need to operate round the clock, the electricity consumption of DSD constitutes about 10% of the overall electricity consumption of government departments. Hence, we constantly look for opportunities to save energy and reduce emission, as well as convert waste to energy. Take the Sha Tin Sewage Treatment Works as an example, biogas from the sludge digestion process is used to generate electricity and heat required, providing nearly 40% of the energy consumption of the plant in the past three years. As such, about 18 million kWh of electricity can be saved a year on average. Besides, the SHWSTW Solar Farm, which was commissioned in late 2016, is the largest of its kind in Hong Kong at present. It can generate as much as 1.1 million kWh of electricity annually.

Way Forward – Being Innovative, Interactive and Collaborative

DSD will continue to be bold and innovative in order to seize the opportunities in the design of new facilities and improvement of existing facilities to make wider use of renewable energy. We hope to progressively increase our usage of renewable energy, from constituting 10% of the overall energy consumption of the Department to 15% in 10 years. We will also collaborate closely with stakeholders. While unfolding various drainage projects, we will take forward schemes to revitalise water bodies and proactively address the challenges arising from climate change.

I would like to express my sincere appreciation for my colleagues’ continuous commitment to work and dedication to serving the public, without which I would not have been able to share with you the success of our work. As the Director, I am proud of their professionalism. I would also like to take this opportunity to thank the public for their constant trust and support towards DSD. We will arrange open days, media interviews and other activities so that the public can learn more about our work. At the same time, we will maintain interaction with students and teenagers through holding seminars in schools, inviting schools to visit our facilities, as well as co-organising job shadowing programme for teenagers, etc., with a view to strengthening communication and joining hands with them to make Hong Kong a more livable city.

Edwin TONG Ka-hung
Director of Drainage Services Department
December 2017