Dian Lake, nicknamed “Sparkling Pearl Embedded in highland,” is surrounded by buildings in Kunming in this January 2010 file photo. From 2006 to 2010, 11 billion yuan ($1.62 billion) has been allocated to finance the clean-up of Dian Lake. The freshwater lake is also called the mother lake by residents in Kunming, capital of South China’s Yunnan province. The water in the lake rated a Grade Ⅴ for five months, three months longer than in 2008. The percentage of total nitrogen has decreased by 12.7% from 2008 to 2009. [Photo/Xinhua] 

The cleaned-up Daguan River transverses Kunming city in January, which is the main river leading to Dian Lake in January 2010 file photo. [Photo/Xinhua]