How Hong Kong can get its water conservation ducks in a row
- World Water Day is an occasion to take stock of progress towards the sixth sustainable development goal on ensuring access to safe drinking water and sanitation for all
- Hong Kong must take its cue from water-stressed nations that have applied sound strategies and technologies to address water scarcity
The 2030 Agenda for Sustainable Development was adopted by all United Nations member states in 2015. It is a plan of action for both developing and developed nations to achieve 17 sustainable development goals, which cover a range of environmental and social issues, by 2030.
Today is World Water Day, so let’s take a closer look at the sixth goal, which aims to ensure access to safe drinking water and sanitation for all.
Water and oil are both liquid resources essential for human survival and economic development. No renewable energy can fully replace oil as yet. So, humanity has to use these finite resources sustainably by conserving them and minimising wastage.
Fortunately, some water-stressed nations have applied sound strategies and technologies to address water scarcity successfully. Hong Kong needs to learn from them to develop sustainable strategies tailored to the city’s situation.
Israel is also considered the global leader in water recycling with around 90 per cent of its waste water treated for reuse in drip irrigation, a water-efficient technology developed for agriculture enabling the cultivation of many types of fruit, including citrus fruit, avocados and mangoes, for local consumption and export.
Most of the reused water has been put to industrial and commercial uses, such as the water-intensive microchip manufacturing industry and cooling for air conditioning systems in commercial buildings. However, the authorities did not stay in their comfort zone, and by launching promotional campaigns, they eventually convinced the public to accept drinking water that contains reused water which meets safe potable water standards.
To tackle water scarcity effectively, we should be paying attention to reducing consumption at source as well as cutting wastage by limiting leakage throughout the water distribution network, both in public and private areas.
In Hong Kong, the Water Supplies Department (WSD) aims to reduce leakage rate from the public mains from 15 per cent in 2019 to less than 10 per cent by 2030 by implementing the Water Intelligent Network, which uses sensors and telemetry.
The city’s total water consumption has kept rising. It broke a new high last year when 1,066 million cubic metres (mcm) of fresh water were consumed. Therefore, the earlier we can meet or exceed the 10 per cent goal, the better.
Based on the city’s 2019 water consumption of 996 mcm, the 15 per cent leakage in 2019 is equivalent to wasting 149.4 mcm of fresh water, or the volume of 59, 760 Olympic-size pools. Clearly this is an avoidable wastage.
There are practical ways to conserve water, such as placing floating solar panels on reservoirs to reduce the water evaporation rate while producing zero-carbon energy to alleviate climate change.
Why don’t we change to using reused water to cool air conditioning systems in our office buildings, data centres and tertiary institutions? By doing so, we can save a lot of precious fresh water until Hongkongers are willing to accept drinking water that has been recycled from sewage like Singaporeans do.
I recall an old Chinese proverb advising people to prepare for rainy days. Today, it is more appropriate to advise people to prepare for droughts.
Edwin Lau Che-feng is executive director of The Green Earth