Today, an aqueduct draws water from the Yongding through Yuyuantan Park to the western city moat, which empties into Liangshui River south of the city. Another aqueduct draws water from Kunming Lake in the Summer Palace down through the Purple Bamboo Park and into the northern city moat, which also replenishes Shichahai, Beihai and Zhongnanhai. The northern moats are drained by the Ba River, which flows into the Wenyu River. The southern and eastern moats are drained by the Tonghui River, which also flow into the Wenyu.