Lucid water from the Danjiang River passed through gates in the Taocha Canal Head of the Middle Route of South to North Water Diversion Project. The monitoring data at that time revealed that the flow into the canal was 420 m3/s, which realized the designed maximum flow of the Middle Route for the first time. That means, after six years of operation, the Middle Route finally reaches the designed flow goal of 420 m3/s, which not only gives a major test to its water transfer capacity, but also demonstrates its stability and reliability.
This spring, the inflow of the Danjiangkou Reservoir has been more than that of the average. Yet, as the flood season comes, it is imperative for the reservoir to spare storage capacity for flood preparation. This creates premises for the sustainable utilization of flood resources of Danjiangkou Reservoir and the normalization of ecological water replenishment. Therefore, Ministry of Water Resources decided to enlarge the flow of water diversion from the Middle Route. Since April 29, water transfer flow at the Taocha Canal Head has been gradually upgraded, and the whole process is expected to linger until the middle of June.
With a total length of 1432km, the operation and management of the Middle Route is pretty arduous. Since its completion on December 12, 2014, the Construction and Management Bureau of the Middle Route has accumulated considerable data and experience in the sphere of operation and management. The project has realized the designed standard flow of 350 m3/s and ensured water transfer during flood and ice periods. As of May 9, the Middle Route has cumulatively delivered 29 billion m3 of water to Henan, Hebei, Tianjin and Beijing. These diverted water can be regarded as the lifeline for 24 cities along the route. Through ecological water replenishment, the project has become an important driving force to step up China’s ecological civilization.
The aim of increasing diversion flow of the Middle Route is to satisfy ecological water demand. The North China Plain, a seriously over-exploited area in China, has an estimated 5.5 billion m3 of groundwater overdrawn every year. In the wake of long time groundwater over-extraction in the North China Plain, it will take a long process to achieve a balance and recovery of groundwater level.
In January 2019, Ministry of Water Resources, Ministry of Finance, National Development and Reform Commission and Ministry of Agriculture and Rural Affairs jointly unveiled “the Action Plan for Integrated Governance of Groundwater Over-exploitation in North China”, which is the first time for China to make a comprehensive plan to address groundwater overexploitation in large scale. In this regard, the Middle Route shoulders a heavy task of groundwater recharge.
From 2017 to 2020, except for meeting domestic water demand of large and medium cities along the route, the Middle Route has made beneficial use of excessive water of the Danjiangkou Reservoir in flood season, to allocate ecological water to rivers and lakes along the route. Currently, over 3.4 billion m3 of ecological water has been diverted, recharging underground aquifers in North China, facilitating the apparent rising of groundwater level, and making a proactive contribution to tackling the problem of groundwater over-excavation in North China and pushing forward the improvement of ecological environment along the route.