At a press conference held on November 9 upon returning from a tour of the Dongjiang River area, Director of Water Supplies Ma Lee-tak said he had expressed to Guangdong province's Water Resources Department (WRD) concerns over the drought problems in northern parts of the province. He said he volunteered to cut back on Hong Kong's intake of Dongjiang water.

The province's WRD officials said they appreciated our offer, but explained that water supplied to the SAR constituted only 3 percent of the river's average annual flow. Moreover, they said, water for Hong Kong is taken from the lower reaches of the river while places experiencing water shortage are situated on the upper course.

Recently, due to a water shortage in Zhuhai, water supply to neighboring Macao has been affected. Even though the two SARs obtained their water from different sources, Hong Kong people are worried about their own water supply.

To Hong Kong people of the older generation, memories of water shortages back in the 1950s are still fresh. At the peak of the most severe drought, water was supplied for only four hours once every four days, which had a very serious impact on the local community.

Tight water rationing not only disrupted daily life, but also hampered the city's fledgling modernization campaign, as we all know how economic development can be heavily restricted by water shortage.

In the early 1960s, when Guangdong and the rest of the mainland were still under the grip of economic hardship and water facilities along the Dongjiang River were much more backward, central leaders, appreciating Hong Kong's need for a more reliable water supply, instructed the Guangdong government to build reservoirs at Bao'an - today's Shenzhen - for that purpose.

It was not until then that Hong Kong was able to overcome once and for all the water shortage problem that had haunted the city for a long time.

After decades of sufficient water supply, the younger generation today have never heard of the term "water rationing", and the current discussion of this issue could provide them with a lesson in history.

More importantly, we can also see from this example the significance of our ties with the mainland, especially Guangdong.

Some of the local media speculated that Hong Kong and Guangdong were at odds with each other. They speculated that the province, using more and more water, was not willing to maintain the present level of water supply to the SAR, and was not happy that Beijing had asked them to do so.

The facts - as demonstrated by Ma's visit - prove such speculations wrong. Water supply to Hong Kong is only 3 percent of the river's average annual volume, so it cannot be a burden on the province by any account.

Nevertheless, we must realize that the world is facing a serious environmental problem. Global warming and other factors are causing persistent drought in many places.

While water shortage is not an immediate problem for Hong Kong, everyone of us must start to form the habit of using less water. This must become a consensus in our society so that we can prepare for the less rainy days ahead.