Polluted shores turned into ecological assets

Once choked off by chemical plants, rusting pipelines and gantry cranes that blocked the view of the Yangtze River, the Wushan area of Nantong, Jiangsu province, has been transformed into a breezy stretch of greenways where parents push strollers and children chase one another along the river.

"Rapid industrialization after 2000 came at the direct cost of the environment," said Wu Haitao, an official with the Nantong Natural Resources and Planning Bureau. Locals told him that even on the hottest July days, riverside residents dared not open their windows, as the air was filled with the smell of chemicals and stagnant water.

To address the damage, the city began phasing out riverside industries in 2015, and accelerated the effort after the launch of the national Yangtze River protection initiative, relocating or shutting down polluting plants and clearing the shoreline.

Authorities dismantled 203 substandard plants and 162 unauthorized small vessels, removed 65,000 square meters of illegal structures, and reclaimed 5.5 kilometers of shoreline. Six sq km of new forest has taken root on the reclaimed land, anchoring a total of 12 km of restored riverside habitat.

Today, 80 percent of the area is shaded by woodland, while 20 km of greenways thread through what was once a heavily polluted industrial belt. The river meets a living edge of trees and pathways, where families linger instead of fleeing the smell.

Nantong's riverfront renewal is part of a national push to revitalize inefficient land, anchored in ecological priorities. While the city healed its scars by returning land to nature, another transformation with a cultural focus unfolded to the southwest in Hangzhou, Zhejiang province.

In Yuhang district, adjacent to the Liangzhu Ancient City — a UNESCO World Heritage Site recognized as evidence of the dawn of Chinese civilization — two massive craters once scarred the landscape. Decades of mining had left cliffs up to 61 meters high, with unstable rock formations posing constant risks of collapse.

Rather than opting for the conventional solution of flattening the site and backfilling the voids, planners saw an opportunity. They realized the deep, stabilized craters were naturally suited for an archive. In 2020, the site was selected to house the Hangzhou Branch of the National Archives of Publications and Culture, transforming a geological liability into a vault for Chinese civilization.

The design team, led by Pritzker Architecture Prize laureate Wang Shu, conducted comprehensive geological surveys for planning. Leveraging the natural topography, they constructed a massive concrete retaining wall against the cliff face. This dual-purpose structure serves as a permanent anchor stabilizing the rock mass while also forming the exterior wall of the main archive repository embedded within the hillside, saving land while addressing slope stability concerns.

To restore the degraded slopes, the team drilled deep into the rock to install steel supports and laid mesh over exposed surfaces, encouraging vegetation to take root in the barren stone. Excavated soil from the original mining operations was also returned to the site — a low-impact approach that reduced costs and provided suitable substrate for native tree species.

Since its inauguration in July 2022, the archive has safeguarded 2.18 million physical artifacts and received nearly 1.4 million visitors from 67 countries and regions, with out-of-town visitors accounting for more than 60 percent as of the end of 2025.

Data from Yuhang district show that vegetation coverage at the site has increased from less than 10 percent to more than 80 percent, soil erosion has dropped by 90 percent, and more than 21,000 sq m of exposed rock faces have been restored to greenery. In addition, air quality has improved significantly, with PM2.5 concentrations falling by more than 30 percent.

The project also demonstrates how high-level cultural investment can drive regional vitality. While admission remains free to ensure public welfare, revenue from cultural and creative products has exceeded 8.5 million yuan ($1.25 million). More importantly, it has acted as a gravitational anchor for the Liangzhu Cultural Corridor, boosting local catering, hospitality and transportation industries, and providing a steady increase in income for surrounding farmers.

limenghan@chinadaily.com.cn