BEIJING — Chinese cities increased their use of recycled water last year amid intensified nationwide efforts to build more water-saving cities, official data shows.

A total of 16.1 billion cubic meters of recycled water was used in Chinese cities in 2021, a rise of 18.9 percent compared with the level in 2020, according to the Ministry of Housing and Urban-Rural Development.

Recycled water refers to wastewater or rainwater that meets certain quality standards and is ready for reuse after treatment.

Since 2015, China has piloted the "sponge city" project in 50 cities to reduce waterlogging, and to collect and recycle rainwater, said the ministry.

As of the end of 2021, some 130 cities had become water-saving cities to serve as models and leading forces in China's urban water-conservation efforts.

To fix weak links in the water-supply network and operation, the ministry has also instructed local authorities to improve water supply facilities and management systems.

The 2022 national urban water conservation publicity week runs from May 15 to May 21, with the theme of "building water-saving cities and promoting green, low-carbon development."

The ministry said its next step is to work with other departments to build sound water circulation networks in urban areas and promote water conservation in cities to help build a green development pattern and encourage green lifestyles.