On June 27, 2023, the Sichuan Provincial Public Resource Trading Information Network released the evaluation results of the design and construction general contracting of the Minjiang Dongfengyan Navigation and Power Hub Project. The project was won by Sichuan Port and Channel Construction Engineering Co., Ltd. with a bid price of 8.94 billion yuan.

Construction scale: The Dongfengyan Navigation and Power Hub is located in the middle and upper reaches of the Minjiang River from Leshan to Yibin, and is the second level of aviation and power hub planned for the 162km long river section from Leshan to Yibin. The control basin area of the dam site is 126484k ㎡, with an average annual flow rate of 2510m3/s. The normal storage level of the reservoir is EL.344.0m, the maximum dam height is 31.5m, the installed capacity is 300MW, and the annual power generation is 13111.9 billion kW · h. The design flood level for a 100 year return period is the same as the normal storage level, and the corresponding reservoir capacity is 106.25 million m3. The total storage capacity of the reservoir for a 100 year return period check flood is 146.5 million m3, and the engineering grade is second class (2).

The general layout of the hub from left to right is as follows: the left bank concrete retaining dam section, fishway, left bank power plant building (10 bulb tubular units), and sluice gate (31 holes, 20 × 13.5m (width × High), right bank ship lock and right bank connecting earth dam section. The dam crest elevation is 349.0m, and the total length of the dam axis is 1325.5m.

The main permanent buildings, such as water retaining structures, drainage structures, navigation structures, and power plants, are classified as Level 2 buildings; Secondary permanent buildings are Level 3 buildings; Relevant temporary buildings, such as diversion buildings, are classified as Level 4 buildings.

The design flood standard for permanent main hydraulic structures is once every 100 years, and the check flood standard is once every 1000 years; The design flood of permanent secondary hydraulic structures is 50 year return period, the check flood is 500 year return period, and the Return period of energy dissipation and erosion prevention flood is 50 year return period.

The designed navigable tonnage is 1000t, and the corresponding waterway level is Class III. The scale of the waterway is 2.4 × sixty × 500m (water depth × Straight segment width × Bending radius); The effective dimension of the ship lock is 220m × 34m × 4.5m (length × wide × Threshold water depth).

The protection of Dongfengyan Reservoir Area mainly includes five protection zones, including polycrystalline silicon factory, Xiba Town, Zhugen Town, Yangliu Niuhua, and Yangliu Qiaogou. The five protection zones are planned to be divided into 15 protection zones for fortification; Build and reinforce 12 sections of embankments; Build and reinforce 15 sections of bank and foot protection; Carry out lifting and filling treatment on 5 lower affected areas; Carry out anti-seepage and drainage treatment for the six immersion protection zones in the reservoir area; Build 17 new drainage and drainage systems; Renovate 11 affected drainage ditches and renovate 139 affected drainage outlets in the reservoir area.

The dam site of the hydroproject is 176km away from the provincial capital, Chengdu, and 40km away from Leshan. The hydroproject is located 300m upstream of Jinli Bridge, Jinli Town, Wutongqiao District, Leshan, and about 10.8km away from Wutongqiao District.

The development task of the Dongfengyan Navigation and Power Hub Project is to focus on shipping, combine power generation, improve water supply conditions, and promote regional economic development. Editor/Zhao E