１工程概况密云水库位于北京市密云县境内，由清华大学水利水电工程系设计，工程原设计标准按千年一遇洪水设计，万年一遇洪水校核，总库容４３．７５亿ｍ３，为华北地区第一大水库。工程于１９５８年９月１日动工兴建，１９６０年９月１日基本建成，是一座以防洪、供水为主具 1 Project Overview Located in Miyun County, Beijing, Miyun Reservoir is designed by the Department of Hydraulic and Hydropower Engineering of Tsinghua University. The original design standards of the project are designed according to the flood once in a thousand years and the flood once every 10,000 years. The total storage capacity is 475 million m3, The area’s largest reservoir. Construction in September 1, 1958 started construction, basically completed on September 1, 1960, is a flood control, water supply as the main