Hainan's largest reservoir is located in Songtao Reservoir, Zhangzhou, in the west of Hainan Island. Hainan's key drinking water source reserve is a multi-functional large-scale comprehensive water conservancy project integrating irrigation, flood control, water supply, power generation, navigation, breeding, afforestation and tourism. Songtao Reservoir from Shamaoling to the north, south to Xishui Mountain, east border with Qiongzhong County, west adjacent to Baisha County. Cross Zhangzhou, Baisha and Qiongzhong three cities and counties.