Miyun reservoir, located 13 kilometers north of Miyun County in Beijing, is located in the hills of Yanshan Mountains. It was built in September 1960. It covers an area of 180 square kilometers, 200 kilometers around Miyun reservoir. Miyun reservoir has a storage capacity of 4 billion cubic meters and an average water depth of 30 meters. It is the largest and only source of drinking water in Beijing. Miyun reservoir has two major inflow rivers, namely Baihe River and Chaohe River.

Miyun reservoir is the largest artificial lake in Asia, known as "Yanshan pearl". There is also a 110 km long road around the lake around the reservoir, which is one of the scenic spots in Jingdong. The average temperature in summer in the reservoir area is 3 ℃ lower than that in the urban area, which is a summer resort. Miyun Reservoir specialty wild Miyun reservoir fish, is a famous fish town in Beijing.

The Jingmi diversion canal is a large-scale channel for transporting water to the capital. It is connected with the regulating pool, with a length of 110km, flowing through five counties and ending at Yuyuantan. It is responsible for irrigation of 2 million mu of farmland and water supply in the capital. It will be completed in two phases. The first phase of the project was built from 1960 to March 1961 from the regulating pond to Xicui village of Changping County; the second phase was from Xicui village to Yuyuantan, from September 1965 to April 1966. The original design flow is 40 cubic meters per second. After lining, the diversion flow is expanded to 70 cubic meters per second. Among them, Miyun section is 12 kilometers long, occupying 1259.1 mu of cultivated land, and has 23 buildings such as control gate, water diversion gate, water drop and bridge. In 1978, a small hydropower station was built in Miyun section with 12 installed units and a total capacity of 12300 kW.