Two decades ago, Li Linzhou had to cover his nose when he took an occasional stroll around Xihu Lake in Fuzhou, capital of Fujian province.

With sewage from nearby communities flowing into its waters, the lake smelled like a cesspool.

Now, Li, who is in his 70s, spends a lot of time in the city's Xihu Park, where he does morning exercises before playing chess with his friends.

"I spend so much time in the park that I met, purely by chance, a classmate from high school days, whom I had not seen for several decades," he said.

He added that the park has become "the backyard garden" for Fuzhou residents.

The venue found favor among locals due to a water pollution treatment campaign spanning several decades, part of which was spearheaded by President Xi Jinping when he served as Fujian governor from 2000 to 2002.

Responding to increased calls from the public to treat water pollution in the lake, in February 2001, Xi presided over a work conference at the park with government officials and reporters.

China News Service reported that he called for immediate action to be taken to treat the polluted water.

At the meeting, it was decided that government departments should draw up plans for pollution in the lake to be treated within three months.

To improve water quality, the lake was dredged, and Xi also urged the authorities to learn a lesson from the pollution and improve planning in the city.

Wang Jing, head of the government office administering the park, said the measures put forward by Xi paved the way for future efforts to treat pollution in the lake.

Xi was also instrumental in protecting Xihu Park, which now covers 77 hectares in downtown Fuzhou, from real estate development, Wang said.

Visited by 40,000 to 50,000 people every day, the park has become invaluable for them, as it provides a respite from busy city life, Wang added.

In 2017, the Fuzhou government launched another campaign to treat pollution in the lake.

Chen Yongfeng, deputy head of the municipal center for water drainage and diversion, said all sewage discharged into rivers flowing into the upper areas of Xihu Lake has been intercepted.

More than 10 villas directly discharging sewage into the lake have been demolished, Chen added.

Meanwhile, sewage from the 697 restaurants near the lake has been sent for standardized treatment, while the two water channels built to intercept such discharges flowing into the lake have been repaired.

Chen said the lake has been dredged for the third time, with 2.95 million cubic meters of mud removed.

After being treated, the water quality in the lake reached Class IV level, meaning that it can be used by industry, he said.

Zhu Chenyi, deputy head of the Fuzhou bureau of housing and urban-rural development, said that in addition to the lake, the local authorities have treated all 44 other bodies of water in the urban area to intercept pollutants.

The authorities are attempting to restore the quality of local waters to enable more aquatic life to thrive, Zhu said.

"If we clean up the rivers and prevent any undue external influences on bodies of water, ecology will slowly recover and fish stocks will arrive naturally," he added.

However, Zhu said sustained efforts by future generations could still be required to fully tackle pollution in the city's waterways.

"The key is to keep emphasizing the concept that green mountains and lucid waters are invaluable assets, along with the need to ensure harmony between humans and nature," he added.