source:China Water Resources News agency editor in charge:Qin Danhua

On December 30, 2020, 172 major national water conservancy projects were closed to impound water at the Chongqing Jinfo Mountain Reservoir.

The Jinfo Mountain Reservoir is located in Nanchuan District, Chongqing City. It is a large (two) large-scale reservoir with a comprehensive utilization of irrigation and water supply as well as power generation. The total storage capacity is 101 million cubic meters. The initial approved investment is 2.037 billion yuan, including a capital of 975 million yuan, a city-level capital of 328 million yuan, a district-level capital of 323 million yuan, and a bank loan of 412 million yuan, the total construction period of the hub project is 50 months. The project started on December 30, 2014. As of December 2020, the spillway project, flood discharge tunnel, irrigation power generation and water diversion construction projects have been basically completed, and a total investment of 2.0235.8 billion yuan has been completed.

The Jinfo Mountain Reservoir is the first high-altitude large-scale reservoir project in Chongqing. Three "blockers" were encountered during the construction process. First, the slope on the left bank where the dam of the reservoir is located is high and steep, with a height difference of up to 180 meters, and traditional construction methods are not feasible. Due to the development of rock fractures, two cracks appeared in the cliff. The construction party adopted the method of zoning and segmented excavation for the high slope, and through strict control of blasting vibration and continuous blasting tests, the excavation and support were ensured. The process connection is scientific and reasonable, and a series of measures such as the filling of domestic concrete materials with high self-compacting characteristics have been adopted to ensure the quality of project construction. Second, a large amount of water gushing occurred during the excavation of the support face of the entrance section of the Ma'anshan tunnel of the canal system. The builders used a variety of geophysical prospecting techniques to carry out geological forecasts and advanced exploration holes. The combination of blocking and drainage, bypass construction and other measures ensured Construction safety and progress. The third is that nearly 3 million cubic meters of rock materials are required for the filling of the Jinfo Mountain Reservoir dam. The project uses the waste rock materials generated during the treatment and removal of the national extremely large geological disaster Zengziyan dangerous rock as the dam filling material, so that it will be turned into waste. Bao, not only solved the project's potential major geo-hazard problems, but also met the material requirements for dam construction and saved construction costs.

The designed irrigation area of the Jinfo Mountain Reservoir irrigation area is 305,900 mu. After completion, the average irrigation gross water supply can reach 47.129 million cubic meters after completion, and it can meet the water demand of urban and rural areas in Nanchuan District. The project also took advantage of the reservoir and channel drop to build a power station behind the dam and two hydropower stations, realizing multiple uses of one water. (Correspondent Liu Tanglin)