Network of pipelines
Since 2015, around 18 billion yuan has been poured into infrastructure projects designed to prevent pollutants from entering the lake, an important step toward remedying the situation.
This was partly achieved by setting up a domestic sewage collection and treatment system of 19 sewage treatment plants, a sewage pipe network that extends 4,461.6 kilometers, 120,700 septic tanks and several other key facilities.
Around 80,000 households and guesthouses in the drainage basin around the lake had at least one small septic tank installed as part of a partially-funded government program.
Li Dechang, from Gusheng village in Wanqiao township, now has two septic tanks in the grounds of his home, which doubles up as a guesthouse business.
He planted vegetables and placed flower pots over the sunken tanks to disguise them and cover up any odors-and his guests remain unaware of their presence to this day.
In January 2015, President Xi visited Li's home and spoke highly of his Bai-style residence and his close family relationship.
All the domestic wastewater from the kitchen, toilets and washing machine is collected in the tanks along with sewage from the toilets and the livestock and poultry barns, drawn into branch pipes, nicknamed "capillaries" by the locals, before being fed to the sewage treatment plants via the main pipe.
Over 96 percent of the sewage generated in the city of Dali, where the government of the Dali Bai autonomous prefecture is located, is now purified before it's discharged-and certainly not into the lake.
Since purified water is not clean enough for daily use but is precious in agricultural irrigation, the water from treatment plants in Shuanglang and a few other towns around the lake are pumped to villages lacking water in the mountains.
Gao Zhihong, Party secretary of the city of Dali, says the difficulty of building such a huge and elaborate system lies in the design of the run of the pipelines and communicating with local residents, not only in terms of negotiating land transfers, but also by persuading them to partly rebuild their houses to install the tanks.
He says he seldom had days off during the years of 2016 and 2017-he had visited every village in the region to convince the villagers to embrace the plan, and help them to overcome their initial reservations.
