On September 25, the headworks hub project of the Xuanwei Reservoir Project in Qiandongnan Prefecture, Guizhou Province—a major national water conservancy project undertaken by Sinohydro Bureau 9 Co., Ltd.—successfully achieved its river closure target, laying a solid foundation for the subsequent comprehensive construction of the main works.

The Xuanwei Reservoir Project is a controlling hub project incorporated into the national 14th Five-Year Plan for Water Security Assurance, and is also a major water conservancy project listed in the Opinions of the State Council on Supporting Guizhou in Forging a New Path in the Large-Scale Development of the Western Region in the New Era. The project is located on the main stream of the Qingshui River in the upper reaches of the Yuanjiang River in Majiang County, Qiandongnan Miao and Dong Autonomous Prefecture, Guizhou Province. It is a flood-control controlling project in the Yuanjiang River basin and a backbone livelihood project for water supply. The project focuses primarily on flood control and water supply, with due consideration for irrigation and power generation. It has a total storage capacity of 124 million cubic meters and an average annual water supply of 83.36 million cubic meters. Sinohydro Bureau 9 Co., Ltd. is mainly responsible for the construction of the headworks hub project and Section 1 of the main water conveyance canal project.

At the critical stage of river closure, Sinohydro Bureau 9 Co., Ltd. organized the work meticulously and dispatched resources scientifically, coordinating the joint efforts of multiple specialized teams including hydrology, blasting, transportation, and emergency response, forming an efficient and interconnected operational system. The company comprehensively overcame numerous difficulties such as tight schedules and heavy tasks, and successfully addressed challenges including large water flows, rapid currents, and complex geological conditions. Through precise hydrological monitoring, dynamic simulation and deduction, and a series of river closure construction trials, a reasonable construction scheme of "single dike end-tipping, from left to right" was scientifically formulated. Through meticulous planning of river closure construction roads and dike embankment filling, the river closure process was ensured to be safe, orderly, and foolproof, fully guaranteeing the successful achievement of the river closure target.

After the project is completed and put into operation, combined with downstream river training and levee construction, it can comprehensively improve the flood control capacity of the old urban area of Kaili City and the Kaili-Majiang new urban area, safeguard the lives and property of downstream residents, and effectively solve the production and domestic water supply problems for 832,000 people in the three districts of the "Kaili–Majiang" central urban area and surrounding rural areas, as well as for 64,900 mu of contiguous irrigated farmland. It will play an important role in promoting the sustainable economic and social development of ethnic minority areas and advancing regional rural revitalization and ecological environment improvement.