On September 6, the National Flood Control and Drought Relief Headquarters formally issued the â€œApproval of the 2011 Three-Gorges Project for Experimental Impoundment Implementationâ€, and the 2011 175-meter experimental impoundment of the Three Gorges Project will start at 0:00 on the 10th.
According to the approval requirements, the storage time for the impoundment of the Three Gorges Reservoir in 2011 will be September 10, and will be stored at 175.0 meters by the end of October or November. The specific water level control at each stage can be appropriately adjusted after approval by the flood prevention and drought relief command department according to real-time upstream and downstream real-time water conditions and its prediction, flood control and drought resistance, and shipping situation and sediment deposition in the river section of the main urban area of â€‹â€‹Chongqing.
Water storage is a systematic project that requires overall consideration of flood control, power generation, shipping, and midstream and downstream water supply requirements. It is based on the principles of safety, science, soundness, and gradualness, scientifically co-ordinating programs, and based on the practice of impounding the Three Gorges Reservoir, and the upper reaches of the Yangtze River Basin. The characteristics of the changes in the hydrological situation are that in order to give full play to the comprehensive benefits of the Three Gorges project such as shipping and replenishment, the total national defense requirements attach great importance to the downstream water demand. From September 10 to the end of September 2011, the discharge flow of the Three Gorges Reservoir is not less than 10,000 cubic meters per second; the discharge flow in October is not less than 8,000 cubic meters per second; the discharge flow from November to December is not less than 39.0 meters at the downstream of the Gezhou Dam. The flow control corresponding to the Three Gorges Power Station guarantees output; from January to April 2012, the water level of the reservoir gradually disappeared, and the water level of the reservoir gradually decreased to 155.0 meters on May 25. It fell to the flood control limit level on June 10, and the reservoir In the fall period, observations and tests of sand flushing and ecological dispatching were carried out. During the water storage and subsidence period, the extent of changes in the discharge flow of the Three Gorges Reservoir and the daily fluctuation of the reservoir water level should be controlled, and a smooth transition should be maintained to reduce the impact on bank slope stability and navigation safety of the downstream bank of the river.
At present, the China Three Gorges Group has already completed all preparations for the experimental impoundment of the Three Gorges Project in 2011, and has compiled the "2011 Three Gorges Project Experimental Test Plan for 175m Experimental Impoundment", which includes hub monitoring, unit testing and sediment monitoring. Earthquake monitoring, water quality monitoring, dry flow floatation cleaning and other aspects. During the impoundment period, China Three Gorges Group will strictly implement the approval opinions issued by the State Administration of Defense and adhere to the principle of â€œscientific forecasting, careful dispatching, full utilization, and service for the peopleâ€™s livelihoodâ€. It will make full use of the automatic monitoring and forecasting system for water and rainfall in the river basin and closely monitor the watershed. And the dynamic operation of the hubs, optimize the operation of reservoirs, and give full play to the benefits of flood prevention, drought resistance, power generation, shipping, and replenishment of cascade hubs.
This year is the fourth year of the 175-meter experimental impoundment of the Three Gorges Project. Prior to this, in October 2010, the Three Gorges Reservoir achieved its first target of 175 meters of water storage, which was 171.43 meters in 2009 and 172.8 meters in 2008.