Author(s): Mable Lam; S. K. Wong; Andy Kwok; Bidaurrazaga Jose

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Keywords: Desalination Plant; Total Water Management; Climate Change; Water Resilience

Abstract: About 20% to 30% of Hong Kong’s fresh water supply (FWS) comes from yield collected in local catchments and the remaining is from raw water imported from Dongjiang, Guangdong Province in the Mainland of China (DJ water). With the rapid economic and population growth in the Greater Bay Area, the cities in the region are competing for the limited water resources. While the stable supply of DJ water could safeguard Hong Kong (HK) against extreme drought conditions, the Water Supplies Department (WSD) of the Government of HKSAR promulgated the Total Water Management Strategy (the Strategy) in 2008 with a view to enhancing HK’s resilience towards climate change, population growth and other uncertainties. The Strategy provides a foundation for the use of HK’s precious water resources and aims to manage HK’s water demand and supply in an integrated, multi-sectoral and sustainable manner. One of the key water supply management initiatives under the Strategy is to diversify the water supply arrangement by developing the option of seawater desalination. WSD completed a review of the Strategy and updated it in 2019. The updated Strategy (Strategy 2019) adopts a two-pronged approach emphasizing on containing fresh water demand growth and building resilience in the FWS with diversified water resources to meet forecast fresh water demand to 2040. Within this framework, the first stage of the Tseung Kwan O Desalination Plant (the Plant), using seawater reverse osmosis (SWRO) technology, is identified as one of the measures to build resilience which provides a strategic alternative source of water supply not susceptible to climate change effects and extreme weather events. The Plant will be integrated into the existing supply system of interconnected network of water treatment works (WTW), pumping stations, service reservoirs and over 6,000km of fresh water mains. In addition to maintaining a reliable water supply during climatic conditions, the Plant will also supplement supply deficits during the maintenance or upgrading of existing WTW within the water network. It will be operated to complement the water production requirements with enough flexibility to adjust to the actual water demand needs. Design and construction of the first stage of the Plant has commenced in December 2019 for operation in 2023. It will have a fresh water production capacity of 50 million cubic metres per annum, equivalent to around 5% of the total fresh water consumption in HK. This presentation will discuss the role of the Plant to ensure the resilience of the FWS within the framework of the Strategy 2019; how the plant has been designed to ensure that train and pumps efficiencies will be the highest possible at all operating scenarios and how implementation of the state-of-the-art isobaric energy recovery devices will help optimize energy costs.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022818

Year: 2022