The Chaobai, Yongding, Beiyun, Daqing and Jiyun are Beijing's largest river systems. Of these five, the Beiyun Canal is over 1300 years old. It is now the largest drianage system for the Beijing's sewage and industrial effluents. The Beiyun Canal is over 124 miles long, and was built in the 7th century. As late as the 1970s, the canal was still suitable for swimming.
Yongcheng Wang was the Central People's Radio reporter, and now the founder and convener of Green Earth Volunteers and Beiyun Waterkeeper organization. She won 3 awards in Asia-Pacific Broadcasting program, elected as the Time/CNN 2008 Environmental Hero, created China’s environmental reporter salon in 2000, and launched the Decade River and Yellow River Decade walks in 2006 to bring media attention to the residents along these major rivers of China. As the Beiyun Waterkeeper, since 2007, Ms. Wang had influenced nearly 10 million people through the decade walks, and weekly Happy Water Tours.