China is the world's second-largest economy, but years of rapid urbanization also brought pollution to many of its lakes and rivers. Many cities across the nation have attached great importance to cleaning these polluted lakes. The South Lake in Jiaxing of eastern Zhejiang Province, home to the memorial "red boat" where the 1st Congress of the Communist Party of China was held, is one of them. Years of economic development and poor management have led to pollution in the lake. Since 2020, a professional team from Shanghai Dredging Co., Ltd. (SDC), a subsidiary of China Communications Construction Company Ltd., has been using everything they can to clean the water. After more than 5 months of hard work, the water quality has much improved. Follow CGTN's Wu Lei on a tour of the South Lake and find out more about the work these engineers are doing.