Yahekou Reservoir is located 40 kilometers north of Nanyang City, Henan Province, in the upper reaches of Baihe River, a tributary of the Han River in the Yangtze River Basin, southeast of Yuhuangding Peak on the ridge of Funiu Mountain, and in the hilly area surrounded by Funiu Mountain and its branch Wuduo Mountain. The dam site is located at the intersection of Yahe River and Nanyang Baihe River in Huangludian Town, nanzhao county, so it is called Yahekou Reservoir. The scope of benefit starts from the southern foot of the eastern end of Funiu Mountain in the north and ends at the junction of Henan and Hubei in the south. It is about 100 km long from north to south and 30 km wide from east to west, with a total area of about 2,400 square kilometers, and irrigates 35 towns and villages.
The reservoir controls a watershed area of 3,030 square kilometers, with a total storage capacity of10.32 billion cubic meters and a storage capacity of 745 million cubic meters.