Water Supply in Hong Kong - Sources of Water

Sources of Water

Hong Kong's three main sources of water are supplied from Guangdong Province; internal freshwater sources stored in reservoirs; and seawater used for flushing toilets. Dongjiang is Hong Kong's major source of water. The designed maximum capacity of the supply system is 1.1 billion cubic metres per annum. The supply contract, costing HK$2 billion a year, has helped the city's economy grow without the interruption caused by water shortages, although the payment constitutes only 0.15 percent of Hong Kong's HK$1.3 trillion gross domestic product. About one-third of Hong Kong's 1,098 square kilometres has been developed as water catchments including reservoirs behind dams on land and three 'reservoirs in the sea', the Shek Pik Reservoir, the Plover Cove Reservoir and the High Island Reservoir.

An interesting facet of the waterworks is the seawater supply system with its separate networks of distribution mains, treatment facilities for screening and disinfection, pumping stations and service reservoirs. Eighty (80) percent of the population, including nearly all housing estates in Hong Kong Island and other densely populated districts, receive sea water for flushing. Some remote districts in the New Territories and some outlying islands do not use the system. In 2010, an average of about 740,000 cubic metres of seawater was supplied each day, up from 330,000 cubic meters each day in 1990/91. Seawater is used to flush toilets and accounts for about 22 percent of total water use in 2008-09.