The 2007 blue-algae pollution crisis of the Taihu Lake, which was reported worldwide, forced Wuxi to change. The city has been central to a national cleanup action in the 2,400-square-kilometer lake, one of the largest freshwater lakes in China. Thousands of factories, many of which produced chemicals, were shut down or relocated.

Nowadays, the oxygen-sucking blue algae still affects some parts of Taihu Lake. But its harm has been decisively reduced. The central government decided earlier this year to increase its funding from 96 billion yuan to 120 billion yuan for a Taihu Lake environmental program that is supposed to meet its targets in 2020.

Wuxi is already receiving benefits from its once-again green hills and clear waters.

Wuxi's tourism authority estimates that tourist revenue is already more than the government's input into restoring the environment.

But Wuxi has new concerns. The chemical fertilizers and pesticides used in agriculture continue to threaten the soil and water.

Environmental protection is an ever-lasting cause. The city will have to fight the traditional agricultural pollution on one hand and the modern pollution from tourism on the other.