Introduction | Tseung Kwan O

The Tseung Kwan O Desalination plant, located in Hong Kong, China, was designed against the backdrop of sustainability as a response to one of the effects of climate change in that region. Williams Sales Partnership (WSP Architects), being an international multi-disciplinary firm, delivered this project as a first-of-its-kind facility using the reserve osmosis technology under local conditions to produce the region an alternative source of clean and portable water that complies with World Health Organization standards for drinking water quality. The Hong Kong Water Supplies Department, as part of its strategy to better prepare Hong Kong for uncertainties, proposed this project to enhance the region’s climate resilience with its unique function and contribute to a sustainable built environment. They selected a consortium of consultants, including WSP, to realise this project.

Tseung Kwan O Desalination Plant by WSP Architects - Sheet1
Entrance to the TKO facility_

The main water sources for the region have been from another city Dongjiang and rainfall from natural catchments. About one-third of Hong Kong has been developed as a water catchment area. The facility was birthed with an inadequate water supply due to a lack of natural lakes, rivers, or substantial underground water sources. Also, the annual rainfall of about 2431.2mm needs to be increased compared to the daily consumption of potable water at 2.89 million cubic meters.

The plant is on an 8-hectare site in a remote area adjacent to Clear Water Bay Country Park and Fill Bank at 137 Area. Despite this contrasting environment, this facility was designed to be harmonious with the surrounding landscape, featuring over 30% greenery, a seafront plaza for the public, and a façade design that conveys modern architecture

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TKO Site Layout_
Tseung Kwan O Desalination Plant by WSP Architects - Sheet3
Aerial view of site_

The facility will have a water production capacity of 135,000 cubic meters per day, which can meet 5% of Hong Kong’s current freshwater demand.

Materials and Construction 

The construction of this project began in December 2019 and will end in March 2023; over 50% of all timber and composite timber products used were from sustainable sources or recycled timber, and about 90% of all building materials are locally sourced from within 800km of the site. The facility has a flexible service design to allow maximum indoor space usage adaptability. 

WSP will also incorporate DFMA (Design for Manufacture & Assembly) in the facade design of several buildings to minimize on-site work, wastage of construction materials, and potential pollution issues. 

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BIM Model of TKO_
Irrigation tank, TKO facility_

Innovative Technology | Tseung Kwan O

The reverse osmosis technology is the most advanced and effective way to produce drinking water, contributing to the sustainable use of water as a scarce commodity. The idea is to use a semi-permeable membrane where most dissolved species are rejected while water permeates it. The reverse process is realised by applying external pressure enough to overcome the osmotic pressure on seawater. This phenomenon is the basis of seawater desalination and water treatment using tubes in modular skids. Reverse osmosis is not only the most advanced desalination system in the world today, but it is also the most efficient and beneficial for the planet: it generates up to 41/2 times fewer greenhouse gas emissions than all other technologies, it doesn’t harm the marine environment, and it’s able to recover a large part of the energy used in the process.

WSP also proposed a series of green features and a green building performance framework. It includes:

  • Maximising the use of renewable energy in treatment facilities 
  • Introducing rainwater harvesting for irrigation, 
  • Solar panels for electricity generation, 
  • Smart street lighting poles, 
  • Roof greenery and 
  • Vertical green walls. 
  • To minimise heat gain and carbon emission during the operation, 
  • Reduce the carbon footprint of the desalination plant.

The indoor environmental quality provided multiple designs to reduce the potential for transmission of harmful bacteria, viruses, and odours and also designed lighting to optimise the illuminance, glare index, and colour rendering index.

WSP, working closely with AJC Joint Venture, is providing multi-discipline engineering design services, including civil, building services, architectural and landscape design, as well as BIM management to enhance the design process and collaboration with cost and time effectiveness throughout the project life-cycle and to improve the coordination amongst various stakeholders and BEAM Plus consultancy for this design, build and operate contract.

Design elements such as large spans of glass, panel walls, fins and good formal compositions were used. The plant’s construction is designed to expand water supplies in the special administrative region and is expected to finish and put into use in 2023.


 osmosis (2023) [Accessed 10 February 2023].

Sea Water Reverse Osmosis(2023),rejected%20while%20water%20permeates%20it. [Accessed 09 February 2023].

Beam plus online exhibition (2023) [Accessed 08 February 2023].


Edet Samuel is a Nigerian based architect with consistent practice experience in the built environment He began his career as a pupil architect in a firm and grew through the ranks of starting out his practice. He holds a Masters degree in Architecture from the University of Nigeria, and he's currently pursuing Doctorate with focus on Intelligent building management systems, architectural forensics, and Urban design. Edet Samuel has been exposed to a wide range of design projects cutting across major categories of buildings, and has contributed this experiences to students' academic works. Edet is broadly interested in contemporary responses and diversification in architecture, especially in areas of improved working drawings & detailing, design information and management, public health architecture in this era of pandemics that has made the home front the first line of defense, and design as 'preventive medicine'.