The level of groundwater in Beijing reached a two decade record high last year, amid local authorities' consistent efforts to curb overexploitation and ramp up replenishment.

In 2021, the city's groundwater was at an average depth of 16.39 meters beneath the surface of the capital's plain area, compared with 16.42 meters in 2001, according to the Beijing Water Authority.

Beijing experienced continuous groundwater depletion after 2000. This was due to overexploitation amid the capital's urbanization and population growth, as well as climate change.

The overall 3-centimeter increase in the groundwater level is a hard-earned result of the city's consistent water conservation efforts.

In 2015, the average depth of groundwater in the metropolis reached 25.75 meters. Since then, the groundwater level has increased for six consecutive years, the authority said.

China's massive South-North Water Diversion Project－which diverts water from the Yangtze River Basin to the drought-prone north－and the capital's water conservation efforts have both played an important role in achieving this significant progress, officials from the water authority told People's Daily.

A year after water from the project reached the capital at the end of 2014, Beijing started to phase out wells while enhancing its efforts to curb groundwater overexploitation, said Jiang Tisheng, deputy head of the water authority's groundwater management department.

Following efforts to locate wells across the capital, the water authority incorporated information on all wells in Beijing into an intelligent water resource management system, he said.

While some wells were demolished, others were sealed off as backup resources or used for groundwater monitoring.

The work "has effectively promoted the restoration of the underground water resources", he said.

Compared with the 2015 level, the total area with groundwater overexploitation in Beijing in 2021 decreased by 82 percent, according to the water authority.

Cross-region cooperation to supplement water in dried-up watercourses in the capital "has had an immediate effect on the restoration of groundwater", Jiang added.

Thanks to years of joint endeavors by Beijing and Hebei and Shanxi provinces to provide additional water, for example, the Yongding River had water through all of its 747 kilometers of watercourses in 2021, the first time in 26 years.

In total, an additional 220 million cubic meters of water were supplied to the river in 2021, he said. These efforts saw the groundwater level around the major river in Beijing increase by 1.74 meters.

Despite water from the South-North Water Diversion Project, however, Beijing remains a water-deficient area. Beijing's per capita water resources currently total about 150 cubic meters, below the world's "absolute scarcity" level of 500 cubic meters, said Yang Jinhuai, deputy head of the water authority.

Against this backdrop, Beijing has made sustained efforts to conserve water. The annual water consumption in the city has remained below 3 billion cubic meters, said Zhang Xinxin, director of the Beijing water conservation office.

During the 13th Five-Year Plan (2016-20), water consumption per unit of the capital's GDP dropped from 15.4 cubic meters to 11.3 cubic meters.

Beijing has also bolstered its efforts to use reclaimed water, she said. In 2021, the total consumption of reclaimed water in the capital reached 1.2 billion cubic meters.