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Hong Kong: The Facts - Water Supplies

Providing an adequate water supply for Hong Kong has always been difficult because there are no natural lakes, rivers or substantial underground water sources. The annual rainfall averages 2 398.5 millimetres but this is insufficient to meet current demands - the average daily consumption of potable water during 2019/20 being 2.73 million cubic metres.

The Water Supplies Department is a government department providing potable water to the people living within the Hong Kong Special Administrative Region. The department also supplies sea water for flushing.

Sources of Water

Hong Kong's two main sources of water are rainfall from natural catchments and Dongjiang water from Guangdong Province. Shortage of natural storage reservoir sites led to the construction of Hong Kong's first ‘reservoir in the sea' at Plover Cove. The initial scheme, completed in 1967, was created by damming, and draining an inlet of Tolo Harbour and had a storage capacity of 170 million cubic metres. The storage capacity was increased in 1973 to 230 million cubic metres by raising the dam. A similar but larger scheme at High Island, completed in 1978, has a capacity of 281 million cubic metres. The total storage capacity of Hong Kong's reservoirs is 586 million cubic metres.

Supply from Guangdong

Dongjiang is Hong Kong's major source of water. Dongjiang water first started to be supplied to Hong Kong in 1965. Today, about 70-80 per cent of water comes from Dongjiang by arrangement with the Guangdong authorities. 738 million cubic metres of Dongjiang water was imported in 2019/20. The Dongshen-Hong Kong water supply system is designed to be capable of providing Hong Kong with 1.1 billion cubic metres per annum.

Sea Water for Flushing

An interesting facet of the waterworks is the sea water supply systems with their separate networks of distribution mains, pumping stations and service reservoirs. In 2019/20, an average of about 848 000 cubic metres of sea water was supplied each day.

Consumption (in million cubic metres)

Fresh Water 2018/19 2019/20
Annual Consumption 1010.75 998.30
Daily Average Consumption 2.77 2.73
Highest Daily Consumption 3.03 2.93
 Sea Water 2018/19 2019/20
Annual Consumption 287.12 310.27
Daily Average Consumption 0.79 0.85

Rainfall and Yield

About one-third of Hong Kong's 1 107 square kilometres has been developed as water catchments.

  2018/19 2019/20
Rainfall (in mm)
Rainfall recorded by the  Hong Kong Observatory 2 333.4 2 272.2
Average rainfall recorded in
    water catchments
2 229.5 2 157.7
Yield (in million cubic metres)
Old Reservoirs 115.63 100.89
Plover Cove and High Island Systems 184.36 156.37

Impounding Reservoir Storage Capacity

The impounding reservoirs and their storage capacities are tabulated below:

Name of Impounding Reservoir Year on Supply Storage Capacity (m3)
Pok Fu Lam Reservoir 1877 233 000
Tai Tam Upper Reservoir 1889 1 490 000
Tai Tam Byewash Reservoir 1904 80 000
Tai Tam Intermediate Reservoir 1907 686 000
Kowloon Reservoir 1910 1 578 000
Tai Tam Tuk Reservoir 1917 6 047 000
Shek Lei Pui Reservoir 1925 374 000
Kowloon Reception Reservoir 1926 121 000
Aberdeen Lower Reservoir 1931 486 000
Aberdeen Upper Reservoir 1931 773 000
Kowloon Byewash Reservoir 1931 800 000
Shing Mun Reservoir 1936 13 279 000
Tai Lam Chung Reservoir 1957 20 490 000
Shek Pik Reservoir 1963 24 461 000
Lower Shing Mun Reservoir 1965 4 299 000
Plover Cove Reservoir 1968 229 729 000
High Island Reservoir 1978 281 124 000

Hong Kong is dependent on adequate storage for the maintenance of a regular supply. If you want to know the storage position of impounding reservoirs, please visit "Current Storage Position of Impounding Reservoirs"

Customer Services

  2018/19 2019/20
Additional no. of accounts (net) 54 000 35 100
No. of accounts as at April 1 3 042 700 3 077 800

Water Treatment

The supply is fully treated by chemical coagulation, sedimentation (at most treatment works), filtration, disinfection by chlorination, pH value adjustment and fluoridation. The drinking water is soft in character and conforms fully to the Guidelines for Drinking-water Quality recommended by the Hong Kong Drinking Water Standards.