High Island Reservoir

High Island Reservoir

High Island Reservoir (English: High Island Reservoir) is located in Sai Kung District, Hong Kong. It is the largest reservoir in Hong Kong by water storage capacity, holding up to 281 million cubic meters of water. The engineering project for High Island Reservoir began in 1969, construction started in 1971, and it was completed at the end of November 1978. It is the last reservoir built in Hong Kong. Together with the second-largest reservoir, Plover Cove Reservoir, they account for 87.2% of the total water storage capacity of 586 million cubic meters across all reservoirs in Hong Kong.

High Island Reservoir was the most costly public works project in Hong Kong during the 1970s. Upon completion in 1978, it cost HK$1.35 billion. For the first time, the government adjusted the administrative division due to the needs of the public works project, splitting the South Sai Kung District Office into the Sai Kung District Office and the Islands District Office. The reservoir also became part of the largest country park in Hong Kong. Its construction submerged many villages, including Lam Nai Wan Village.

The original site of the reservoir was the Kwun Mun Channel (also known as Kwun Mun Strait or Kwun Mun Waterway), which, like Plover Cove Reservoir, is an offshore reservoir. The project involved constructing two main dams at either end of the Kwun Mun Channel, connecting the Sai Kung Peninsula with what was then Hong Kong’s third-largest island, High Island (Liangchau). These two main dams are 64 meters high, along with three auxiliary dams.