At dawn, beside the lush, green Yundang Lake, joggers tread lightly along the lakeside path, newlyweds capture memories in wedding photos, and migratory birds skim the water's surface, sending ripples across the lake.

Today, the lake, with its sparkling waters and vibrant ecosystem, has become a "living room" for the coastal city of Xiamen and a green landmark.

However, more than 40 years ago, the scene was starkly different. At that time, the lake was still an inner bay fishing port, into which untreated domestic sewage and industrial wastewater were discharged for years. The lake became black, foul-smelling and devoid of aquatic life, and locals referred to it as a "dead lake".

In 1985, Xi Jinping, then 32 years old, arrived in Xiamen to serve as executive vice-mayor. From the outset of his tenure, he adopted a long-term vision.

The following year, he led the formulation of the 1985-2000 Xiamen Economic and Social Development Strategy, which laid out an ambitious blueprint for the city's development over the next 15 years.

Personally spearheaded by Xi, who is now Chinese president and general secretary of the Communist Party of China Central Committee, the strategy was developed by a task force comprising over 100 experts, scholars and staff members from over 10 institutions. After 18 months of in-depth research and repeated deliberations, the team produced a systematic report of over 200,000 words.

The report placed environmental protection at the heart of urban development and issued a stern warning about pollution in Yundang Lake: "It must be given high priority and addressed urgently."

A striking line from the strategy reads: "Xiamen's ecological environment is truly superior. While developing the special economic zone, we must guard against pollution and maintain ecological balance, to preserve and create a beautiful living and production environment for the people of Xiamen and future generations."

The document offered a comprehensive plan for Xiamen's development, covering economic development, industrial layout, institutional reform, sci-tech innovation, ecological protection, cultural advancement, and education and talent development. It proposed the preliminary idea of building a free port, initiating a new chapter in Xiamen's modernization.

"Looking back now, the strategy was visionary and provided an answer to the question of how to develop the special economic zone," said Zheng Jinmu, former deputy director of the then Xiamen municipal planning commission and a contributor to the drafting of the report.

"Back in the 1980s, Xi Jinping showed a remarkable sense of mission, willing to lay the groundwork and plant the seeds for future generations. That spirit is truly admirable," Zheng said.

Liu Lianzhi, a former associate professor at Xiamen University who also participated in drafting the report, recalled that at the time, developing the Xiamen Special Economic Zone was like "crossing the river by feeling the stones".

"In this process, Xi Jinping was the one leading the people of Xiamen across the river," Liu said. "One of the most important lessons from this strategy is that long-term, sustained and actionable planning is critical. Planning must be realistic and tailored to local conditions."