Why Hong Kong must stop wasting water right now: don’t wait for the drought

Water is basic to human survival. Today, March 22, is World Water Day. Its theme is “Leaving No One Behind”.

To many people living in developed economies, fresh water seems an abundant natural resource that does not need conserving. But, according to the World Health Organisation, 2.1 billion people cannot get safe drinking water at home on a daily basis.

In 1963, when Hong Kong suffered a severe drought, fresh water was available for just four hours every four days! Today, we are paying more than double the unit production cost of locally collected rainwater to buy water from Dongjiang, which accounts for nearly 80 per cent of our total water consumption.

Blessed with the seemingly unfailing water supply, our average daily per person fresh water consumption was around 132 litres in 2015, which is a massive 21 per cent higher than the global average.

Although the mainland authorities have emphasised that they will keep supplying Hong Kong with enough water as a political mission, there are many uncertainties, such as climate change, pollution and competition from the fast-growing Pearl River Delta population. These should not be overlooked.

There is an old Chinese saying: plan before it rains. Applying such wisdom to our water risks, we should plan before a drought happens.

The water management strategy formulated by the Water Supplies Department emphasised promoting conservation, followed by developing new resources. This was moving in the right direction, but we need to move faster.

I suggest the following steps to address demand and supply issues:

Demand side

• Review the heavily subsidised water tariff so that users pay for the full cost of water;
• Mandate all new buildings, both public and private, to use the most water-efficient devices;
• Make transparent the water consumption data of all buildings to encourage water saving;
• Speed up the replacement of old water pipes to lower the current leakage rate of 15 per cent;
• Educate the public about the importance of water conservation, including the benefits of short showers and eating less meat (beef cattle are very heavy consumers of water);

Supply side

• Turn grey water (water collected from baths, showers, wash basins, kitchen sinks and laundry machines) and harvested rainwater from buildings into reusable water for wider applications;
• Explore the option of installing grey water reuse systems in new buildings and retrofitting old buildings to reuse grey water for non-potable purposes.

Without water, human beings cannot survive, let alone thrive economically. Let’s act before the drought.

Edwin Lau Che-feng, executive director, The Green Earth