The Annual Meeting of Chinese National Committee on Large Dams (CHINCOLD) was held in Beijing from April 11 to 15, 2022. At the opening ceremony of the meeting, the winners of the 3^rd International Milestone Concrete Dam Award were announced. The award went to Jinping I Arch Dam from China, Glen Canyon Arch Dam from USA, Xiangjiaba Gravity Dam from China and Okutadami Gravity Dam from Japan. LIU Weiping, Vice Minister of the Ministry of Water Resources together with more than 1500 delegates joined the award ceremony.

To summarize the important technical achievements in dam construction and identify the milestone dam projects, Chinese National Committee on Large Dams (CHINCOLD) and United States Society on Dams (USSD) jointly initiated the evaluation and selection of the International Milestone Concrete Dam Projects in 2011. The nominated projects were recommended by national committees of the International Commission on Large Dams (ICOLD) and eminent experts worldwide. So far, the milestone concrete dam award had been selected for 3 sessions. 13 concrete dams were awarded as the International Milestone Concrete Dam Projects, including Three Gorges Gravity Dam, Ertan arch dam, Xiaowan Arch Dam from China, Hoover Arch from USA, Grand Dixence Gravity Dam from Switzerland etc.

As the representatives of awarded dams, WANG Jimin, Deputy General Manager of Yalong River Basin Hydropower Development Co., Ltd., Del Shannon, President of United State Society on Dams (USSD), WANG Yihua, consultant of China Three Gorges Construction Engineering (Group) Co., Ltd. and Masayuki Kashiwayanagi, Managing Director of Japanese National Committee on Large Dams (JCOLD) respectively gave a brief introduction on each awarded dam at the opening ceremony.

The opening ceremony was videotaped and uploaded to CHINCOLD Cloud Platform at https://www.chincold-smart.com/live/meeting, which has been visited for more than 7000 times after the conference. The event was reported by People's Daily, China Water Resources News and China Electric Power News.

WANG Jimin, deputy general manager of Yalong River Basin Hydropower Development Co., Ltd., introduced Jinping I arch dam

Del Shannon, President of USSD, introduced the Glen Canyon Dam  

WANG Yihua, consultant of China Three Gorges Construction Engineering (Group) Co., Ltd., introduced the Xiangjiaba Dam

Masayuki Kashiwayanagi, Managing Director of JCOLD, introduced the Okutadami dam

Brief introduction on the winning projects of the 3^rd International Milestone Concrete Dam Project Award 

1. Jinping I Arch Dam

Jinping I Arch Dam in China (H= 305m).

As a 305m-high double curvature concrete arch dam, Jinping I Dam is the highest dam in the world recognized by Guinness World Record. Jinping I Hydropower Station resides on the Yalong River, in Liangshan Yi Autonomous Prefecture, Sichuan, and tops all other cascade hydropower stations in the lower reach of Yalong River. Costing a total of RMB 40.1 billion, it has a total installed capacity of 3,600MW and a multi-year average annual power generation of 16.62 billion kWh. Since it was put into operation, it has significantly improved the ratio of clean energy in China's energy structure, assisted in the poverty alleviation of the west part of China, and helped the flood control of the Yangtze River. Jinping I Reservoir has a normal storage water level of 1,880m and a dead water level of 1,800 m. Under the normal storage water level, the storage capacity is 7.76 billion m³ and the regulation capacity is 4.91 billion m³. Therefore, it is an annual regulation reservoir. The dam has a crest elevation of 1,885m and a minimum foundation surface elevation of 1,580m. Its crown cantilever has a crest thickness of 16m and a base thickness of 63m. For the top arch, its center line has an arc length of 552.23m; its thickness-to-height ratio is 0.207; its arc-to-height ratio is 1.811. The dam body has used 5.58 million m³ of concrete. During construction, a series of key technical issues were encountered and solved. These complicated technical difficulties made the construction extremely challenging. In 2018, Jinping I Hydropower Station won the Award for Outstanding Project of the Year of International Federation of Consulting Engineers (FIDIC).

2. Glen Canyon Arch Dam

Glen Canyon Arch Dam in the United States (H=216.5m) 

Glen Canyon Dam is the main part of the Colorado River Storage Project to serve the water needs of the Upper Colorado River Basin States. The primary purpose of the dam construction was to store water for delivery to the Lower Basin States and produce hydroelectricity to fund participating projects throughout the Upper Basin. Secondary benefits of Glen Canyon Dam include the storage of treacherous peak flows in Lake Powell and recreation administered by the National Park Service. Construction of Glen Canyon Dam officially began on October 16, 1956, when President Dwight D. Eisenhower telegraphed a signal from Washington, D.C. that triggered an explosion along the canyon walls. From 1956 until completion in 1966, the Bureau of Reclamation (Reclamation) oversaw construction of the 216-m-high, constant-radius thick-arch structure with a 12.5-m diameter tunnel- type spillway through each abutment and an outlet works through the dam near the left abutment. The indoor type powerplant is located immediately downstream of the dam and is equipped with eight 165 MW generators, driven by 254000 horsepower vertical-axis Francis turbines at gross hydraulic head of 160 m. Glen Canyon Dam is one of the most important dams in the United States. Great progress and technological innovation have been made in the design and construction of concrete dams.

3. Xiangjiaba Gravity Dam

Xiangjiaba Gravity Dam in China (H=162m)

Xiangjiaba Hydropower Project, the utmost downstream project of the cascade development on the Jinsha River, is the backbone power source of the National West to East Electric Power Transmission Program. It is developed primarily for power generation, concurrently with multipurpose benefits of navigation improvement, flood control, irrigation, sediment retention, and reregulation for the Xiluodu Hydropower Station. It is the only project on the Jinsha River that boasts huge farmland irrigation and high navigation capacity. It can play an important role in safeguarding the national energy security, improving the efficiency of water resources utilization in the river basin, promoting the connection of Southwest China with Central China and East China by waterway, boosting the regional socio-economic development, and advancing the environmental protection. The project has a normal storage level of 380 m, a total reservoir capacity of 5.163 billion m³，a total installed capacity of 6,400 MW (8×800 MW), a mean annual power generation of 30.88 TWh, a firm output of 2,009 MW, an irrigated area of 353,330 ha, and a total investment of 54.165 billion Chinese Yuan as per the cost estimate at the feasibility study stage.

4. Okutadami Gravity Dam

Okutadami Gravity Dam in Japan (H=157m)

Okutadami hydropower project had been enacted in 1951 as the national project for the recovery and the development of the economy in Japan after the World War II. Okutadmi dam was designed for the Okutadami hydropower station which was expected to supply 500 GWh electricity annually to Tokyo capital area. The Okutadami dam completed in 1961 is a 157 m high concrete gravity dam (PG). It was the third case of PGs beyond 150 m high in Japan. It is located in central Japan and situates the most upstream in the Tadami river which originates Lake Oze and flow toward the north. The total installed capacity of the project is 360MW. After 40 years of operation, the capacity was expanded by 200MW to meet the demand of power consumption peak. The total storage capacity of the reservoir is 600 million m³, which is the largest reservoir in Japan. The dam is located in a deep mountain area, with heavy snow in winter which caused great difficulty in construction. A road of 22 km has been built for the construction. In terms of temperature control, cooling water pipes are used, longitudinal joints and joint grouting are set at the lower part of the dam, and cable crane is used as the main transportation equipment. These technologies provide the foundation for the dam construction in Japan afterward. Experienced the Sino Vietnam earthquake and aftershock in Niigata county, the dam has operated stably for 60 years.