Sustainable Strategies for the Northern Metropolis Development

Prof. Zhongming LU, Assistant Professor, Division of Environment and Sustainability, HKUST
Dr. Faith CHAN, Associate Professor, University of Nottingham Ningbo China


The Northern Metropolis (NM) concept plan has strong public support, so it is important to do a good job in its detailed planning and eventual execution.

Hong Kong can use this opportunity to design and realize a truly sustainable project for the city. The NM plan must be ‘carbon-neutral’, ‘climate-resilient’, and ‘liveable’ as these are essential elements of a sustainable city.

Other cities are attempting to achieve these outcomes too, such as Mainland China’s Xiong’an New Area, which is designed to be a near-zero carbon city. In Britain, London is committed to becoming carbon neutral by 2050, and the mayor has proposed to push the target forward to 2030s.

Achieving carbon neutrality is one goal but cities also need to be climate-resilient, resource-efficient, healthy, and liveable. City (re)development is a long-term adaptive process. Time will tell which cities can achieve those features.

Hong Kong can start with good planning now.


Moving Forward

Developing the NM as a truly sustainable project is a challenging task for the HKSAR Government because it is multifaceted and involves many diverse interests. It is therefore important to have a highly transparent and collaborative process, such as using CIM, to showcase where the costs and benefits are. The process will necessarily involve the public and private sectors, and also academics, businesses and communities. New ideas, such as using digital technologies, NBS, and green financing would truly enable Hong Kong to take a giant leap forward.


Digitalization of the development

The full development of the NM will take many years. It is never easy to design every aspect of a large project that will be implemented over a long stretch of time. As implementation proceeds, issues will also emerge that may not have been fully anticipated during the planning stage. One way to deal with it is to digitalize the development so that every aspect of construction and operation of the project could be monitored real-time so that appropriate response could be applied. It could also assist in using new technologies to make further sustainability gains.

There are two similar digital modelling technologies helpful to city planners and developers:

  1. Building Information Model (BIM) is now commonly used around the world. It allows construction professionals to carry out design and construction works in a virtual environment, which helps to optimize the construction process to avoid mistakes and hence reduce risks and costs. The HKSAR Government started to encourage its use in public project from 2017, and more and more public and private projects now use BIM.
  2. City Information Model (CIM) is relatively new although it is similar to BIM in concept but is applied city-wide. It is a sophisticated digital platform that allows planners, architects, and other built environment professionals to collaborate on large-scale city designs and projects. In developing Xiong’an New Area, CIM was applied to create the digital twin of the new area.

The design of the NM project could benefit from using CIM. It will require the integration of all kinds of data, the details of which will need to be worked out. Beyond details about buildings and infrastructures, other types of data such as materials for building and infrastructures, resource consumption (e.g., energy, water, sewage and solid waste), and regional environmental quality (e.g., air, water, and biodiversity) would also be needed.

Should the HKSAR Government consider using CIM to help design the NM, it would be hugely important in the world in the application of this new technology, and it would give Hong Kong the opportunity to bring many professionals and stakeholders together to help co-design and plan an important project.


Mandatory regulations for nature-based solutions

The International Union for Conservation of Nature defines nature-based solutions (NBS) as actions to protect, sustainably manage, and restore natural and modified ecosystems that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits. They are widely promoted in many parts of the world. Blue-green infrastructures that mimic the natural surface of hydrological cycle to avoid heavy runoffs and pollutants is an engineering example. Besides reducing flood risk, the other benefits of green infrastructures include reduced urban heat, improved health, and increased recreational opportunities.

The Drainage Services Department (DSD) has already implemented several blue-green projects, such as improvement works related to the Ho Chung River, Upper Lam Tsuen River, Kai Tak River, Yuen Long Bypass Floodway, Tai Wai Nullah, and Jordon Valley Nullah. These have proven to be popular.

Interestingly, DSD is going ahead with the Yuen Long Barrage Scheme that is in the NM. The barrage scheme is a flood prevention plan that includes the revitalization of more than 2 kms of nullah by converting the concrete-lined channel to urban green river corridor to promote biodiversity, and local beautification that allows for public enjoyment.

DSD is also familiar with mainland China’s ‘sponge city’ program, which was first initiated in 2014. The concept of sponge city is an integrated urban water management approach to address urban surface runoff, water pollution, and flooding risks. The concept includes the technical solution referred as ‘blue-green’ infrastructure in Hong Kong. Shenzhen is piloting sponge city in Guangming District to manage urban water, wastewater, and stormwater sustainably. There is no reason why the NM masterplan projects cannot explore using sponge city/NBS concepts too. There could be many NBS projects in NM, and throughout Hong Kong.

The abovementioned projects are public projects. The HKSAR Government can also consider incentivizing the private sector to use NBS. In some US cities, the application of green infrastructures is required by legislation. In Atlanta, Georgia, the Stormwater Ordinance requires all new development and redevelopment to manage the first inch of rainwater that falls on a site using green infrastructure. The HKSAR Government may wish to consider legislation too in due course.


Nurturing a green finance market for low-carbon building technologies

Decarbonization can be promoted across the urban scale as well as buildings. While the power utilities are the key players in decarbonizing electricity, buildings play significant roles. Commercial buildings consume a very significant proportion of electricity and natural gas in Hong Kong. Can we plan for buildings in the NM to be highly energy efficient?

There are two aspects to this challenge. Firstly, the electricity supplier for the NM is CLP. It has to secure clean electricity by generating it locally and/or importing it from the mainland. Indeed, a portion of its electricity is already clean, as it comes from the Daya Bay Nuclear Plant. It goes without saying that its own power generation (currently using more natural gas) has to be as efficient as possible, and its electricity distribution system must also be highly efficient. It is good news that CLP is exploring the possibility of generating hydrogen in Hong Kong although this is still at the early exploratory stage.

Secondly, the buildings themselves must be highly energy efficient, and the occupants must know how to save energy on an on-going basis. There are few (if any) truly zero carbon high rises in the world. However, there is a lot that building developers can do to design new green buildings using green and even NBS designs – for example, the Hong Kong Green Building Council Zero Carbon Competition in 2021 generated several very exciting designs. Developers can raise green bonds to secure finance for such buildings. It is clear that Hong Kong has the talent to create such buildings – the incentives need to be there for them to flourish. Policymakers need to craft the right policies and incentives.

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