As a proud local, Yan has witnessed the improvements over the past decade, noting that the acuminate water lilies that now grow in Erhai Lake are a physical sign of the lake's health. Acuminate water lilies, or Ottelia acuminata, are delicate aquatic plants that famously only grow in high-quality water.

Erhai's water quality has been maintained at "excellent" or "good" levels over the past few years, according to publicized announcements.

"My ancestors and I have always lived beside Erhai Lake, and it has nurtured us for centuries," Yan said, adding that the enhanced water quality has also boosted tourism. His family's small shop has increased its sales tenfold from the previous 50 yuan ($7) a day.

Back in the 1980s, overexploitation and inadequate conservation efforts led to severe lakebed erosion and aggravated watershed pollution in Erhai Lake, causing a rapid decline in water quality.

The region was hit by two massive blue-green algal blooms in 1996 and 2003, during which the lake's surface transformed into a sickly green layer, making it one of China's most polluted lakes at the time.

In 2006, the State Council, China's Cabinet, approved a major national water pollution control project targeting Erhai Lake's restoration, whose subsequent efforts gradually improved the water quality. However, new challenges arose in 2011 when the prefecture designated tourism as a pillar industry, allowing outside investors to lease local residential land for guesthouse construction. The unregulated development became a major pollution source, causing another algal bloom two years later.

During President Xi's 2015 inspection tour of Yunnan, he stressed the ecological protection of the lake and called for the protection of the lake's natural beauty forever.

In response to Xi's call, the local government launched a series of ecological projects to prevent and control pollution and restore the environment of Erhai Lake.

These involved the launch of a rectification plan for the hospitality sector in Erhai Lake in 2017, with the shutdown of nearly 2,000 guesthouses and restaurants in the designated core protection area.

Despite the short-term reduction in economic activity at the time, especially in terms of tourism, the long-term ecological restoration would pay off for all stakeholders in the end.