Yihe River, originating in Yiyuan County, Shandong Province, is the mother river of Linyi with two sources: north and west. The Xiaobudong Rubber Dam of Yihe River, built in 1997, is 1135 meters long. It has stored 16,000 mu of landscape water in Linyi City. It has been selected as one of the 18 National Water Conservancy Scenic Spots in China and the longest rubber dam in the world in Guinness World Records.