Providing an adequate water supply for Hong Kong has always been difficult because there are no natural water sources in the city and water from rainfall is insufficient to meet the increasing demands to support the economic and population growth.
Thanks to innovative solutions adopted by the city over the years that there has not been water rationing in Hong Kong since 1982. However, climate change has increased the risk of drought, potentially affecting more than 40 million people in the region of Mainland China, including Hong Kong.
Further, the very high density of Hong Kong makes it difficult to access the water supply systems for extensive replacement and rehabilitation works to tackle water leakage, without disturbing very high numbers of citizens and businesses.
Hong Kong’s Total Water Management strategy started in 2008 as a long-term strategy for sustainable use of water resources. Some initiatives under the project have been completed whilst others are still being implemented, and are either in the planning or construction stages in order to meet the city’s goals by 2030.
In collaboration with multi-sectoral stakeholders and the public, programmes on the demand side such as territory-wide water loss management and multi-pronged, community-wide water conservation measures, including establishment of a “Water Resources Education Centre”, launching of the “Cherish Water Campus” for primary school students, and “Let’s Save 10L Water” campaign are being implemented. With a view to tackling water loss, Hong Kong has successfully implemented a large-scale replacement and rehabilitation programme of 3,000km of water mains and further switches its strategy to smart network management for timely detection and action to maintain the network healthiness. The fresh water and saltwater saved from these strategies has already been achieving 50% of the 2030 CO2 reduction target.
As for supply management, in order to conserve precious freshwater resources, Hong Kong has been expanding its large-scale seawater flushing system increasing the population coverage from 80% to 85%. Apart from the existing three water sources (imported freshwater, local yield and seawater), the city has been actively exploiting the three alternative sources of reclaimed water, recycled grey water/rainwater and desalinated water to further strengthen its supply structure.
Along with the TWM strategy, a hydropower plant, solar panels, a wind turbine and wave-powered devices have been installed in water treatment works and pumping stations, while other new energy-saving initiatives are currently under consideration. The facilities have contributed about 320 tonnes of CO2 reductions in 2015 alone.
Total Water Management’s targets include:
• By 2030, the target annual CO2 reduction from the water saved since 2011 is about 87,900 tonnes (20% of the total CO2 emission in the water supplies department in 2014/2015).
• By 2030, an extra 2,900 tonnes of CO2 reduction is set to be achieved through the energy saving measures put in place across Hong Kong’s waterworks operations.
• By 2030, about 200 mcm of freshwater and 24 mcm of saltwater would be saved annually. It corresponds to about 21% and 9% of water consumption in 2015 respectively, and the total monetary value of water losses avoided amounts to about $240 million year.
• Alternative water sources could deliver annual saving of up to 103 mcm of freshwater, equivalent to 11% of total freshwater consumption in 2015.
The TWM strategy has substantial financial and environmental co-benefits. It brings a gradual increase on annual saving, helps save water resources, protects natural freshwater ecosystems, safeguards the health of the citizens, creates resilient communities and leads to better land-use planning for the city’s sustainable development.