Fifty-year-old Heng Degan is a police officer in Yangzhou City of east China's Jiangsu Province. Everyday, he helps local people with household registration paperwork and delegate manpower to deal with emergencies.

But since 2016, he's taken on another role – a river chief. The new role means he is in charge of river and creek pollution prevention and ecological restoration. 

"In our 12-square-kilometer Wantou area, there are 40-plus rivers in big and small sizes. I have to inspect all of them every one to two months," said Heng, the deputy chief of Wantou Police Station.

Heng's river chief routine ranges from cleaning garbage, stopping polluting activities and monitoring the river quality. However, his role as river chief is not part of his job as a police officer, therefore, most tasks of river chief are carried out in his spare time.

"There used to be many fishermen stealthily catching fish in this river," he said. "They threw their nets out or even used fish-eating birds to catch them. If we don't do anything, it will hugely affect the quality of the river."

In December 2016, to better protect the environment, China decided to assign each waterway with a river chief. However, even before the scheme was implemented, Heng had been doing the task for years.

According to Heng, local residents used to plant green pepper, eggplant and cucumber on the riverbank, which is a public area. After a long period of persuasion and inspections, the residents finally gave up growing vegetables.

"Now the water has become cleaner, riverbanks turned greener, and the overall ecological environment has been better," said Heng.

According to the Research and Development Center of the Ministry of Water Resources, there are over 60,000 river chiefs in Jiangsu Province – some are employed by the government and some are volunteers – all assigned the task of protecting the rivers.