"Although affected by the COVID-19 epidemic, the project is expected to be completed as scheduled," he said, adding that many construction materials are from cities in Guangdong province, which helps to save time.

Environmental protection is highlighted in the project, Zhang said, adding that many temporary components on the construction site will be recycled, including concrete and solar panels.

The desalination plant is part of a wider strategy of the SAR to diversify its water sources in the face of various challenges, including increasing local demands due to population and economic growth and occurrences of extreme weather.

Surrounded by the sea on three sides, the city of Hong Kong has faced a lack of fresh water resources in the past.

Before the 1960s, the water use of residents mainly depended on rainfall.

Lee, the engineer from the water supplies department, who is in his 40s, said, "When I was a child, I often heard the elders say that the water supply was once every four days and could only be used for four hours at a time."

There was an old saying at that time in Hong Kong that when you used water upstairs, you had to shout to your neighbors downstairs to turn off the faucet due to low water pressure, he said.