Water rationing Until 1964 water rationing - the act of limiting water usage for each household by water providers - was a constant reality for Hong Kong residents, occurring more than 300 days per year. The worst crisis occurred in 1963–64 when water was delivered only every 4 days for 4 hours each time. The territory, which was under the British colonial administration, then embarked on a three-pronged approach to supply water to an increasing population. (Hong Kong's population increased from 1.7 million in 1945 to about 6 million in 1992.) The strategy involved flushing toilets with seawater, the construction of larger freshwater reservoirs in bays that used to be covered by the sea, and water imports from mainland China. In 1960 legislation was introduced to promote seawater flushing on a larger scale, followed by substantial investments in a separate network. However, the system was unpopular due to the need to build a separate plumbing network in each house. Seawater initially was sold, but from 1972 on it was provided for free and the costs of the system were recovered through the drinking
water tariff. In 1991, about 65 percent of Hong Kong's households used seawater for flushing. By 1999, the number of conforming households had increased to 79 percent. Another pilot desalination plant utilized reverse osmosis in Tuen Mun in Hong Kong during the year of 2004, but this plant lasted only one year. This plant was made as an experiment to evaluate the efficiency of reverse osmosis. Construction of the Tseung Kwan O Desalination Plant began in 2019, and it began supplying water to the public in 2023. It utilizes reverse osmosis and is projected to meet 5-10% of fresh water demand. Desalination is an intriguing topic that would definitely increase the rate at which clean water can be supplied as well as help prevent the overuse of water pipes for transportation, but it is an expensive process that currently does not yield too many benefits.
Protecting raw water quality The pollution of raw water supplied to Hong Kong became an increasing concern that triggered a variety of activities designed to protect the quality of raw water. In 1998 the intake of the water pipeline was moved further upstream on the Dongjiang River where water quality was better. In 2003 an 83 km dedicated aqueduct was completed, thus reducing the vulnerability of the supply to pollution. Additionally,
wastewater treatment plants were constructed in settlements in the Dongjiang basin and polluting industries were removed, thus protecting the water at the source. In 2006 a Water Supply Agreement was signed with
Guangdong Province for a "flexible" supply of Dongjiang water.
Total water management In 2003 the government of Hong Kong announced what it called a "total water management programme". In 2005 a study was commissioned and the results were broadly discussed. Based on the study the government reaffirmed its approach to water management, but also started new initiatives concerning leakage reduction, water conservation,
greywater reuse,
rainwater harvesting, as well as pilots for the reuse of
reclaimed water and
desalination. For example, the government plans to provide reclaimed water from Shek Wu Hui Sewage Treatment Works for consumers in
Sheung Shui and
Fanling for toilet flushing and other non-potable uses, as well as pilot desalination plants in
Tuen Mun and
Ap Lei Chau.
Desalination comeback Because the price of imported water increased from $1 to $3 per cubic meter, the Hong Kong authorities announced in 2011 that the government would build a 50,000 cubic metre per day seawater desalination plant. The plant will allow greater resiliency against droughts that may become more severe due to climate change. ==Sources of water==