K-water has applied IWRM (integrated water resource management) practices across the whole process of water cycle, which would enable the efficient use and management of water resources, including rainfall and water flowing from basins and rivers.
In Korea, two thirds of gross rainfall is concentrated in the wet season, along with extreme variations in river discharge, which is why it is very necessary to control water storage and discharge with dams and other hydraulic structures.
K-water has operated & maintained 17 multipurpose dams, 14 dams dedicated to water supply, and Nakdong R. Estuary Barrage with its own ICT-based water management system to ensure the optimal management of water storage & discharge. Their flood control capacity account for 95% of the gross domestic flood control capacity or 4.9 billion tons, with their water supply capacity explaining 66% of the gross domestic water supply capacity or 12.4 billion tons.
Multi-purpose dams are operated to satisfy various purposes including flood control, water supply, and hydropower generation. For these functions, it is absolutely essential to secure optimal operation of water gates through continuous measurements and analysis of information on rainfall, inflow and outflow, weather conditions, and water quality. In the future, K-water will exert all of its efforts to maintain scientific operation and management of water resources through implementation of an integrated water management system for each river system
The Soyanggang Multi-purpose Dam opened a new chapter in the history of civil engineering in korea. It is one of the biggest rockfill type dams in Far Eastern Asia. The Soyanggang Dam, built as a part of Four Major Rivers Development Plan, is 123 m in height, 530 m in length and has a volume of 9.6 million ㎥. It also generates 200,000 KW, a capacity large enough for power 5 million 40W-rated fluorescentLights. Notably, Soyanggang Dam contains 2.9 billion ㎥ water. This dam provides living, industrial and agricultural water of 1.2 billion ㎥ to the area adjacent to Han River and Seoul metropolitan areas. It also stores 770 million ㎥ water for flood control, serving as the front line for preventing floods on the downstream of Han River.
The Chungju Multi-purpose Dam, built in the Southern Han River basin which crosses the center of Korean Peninsular, is the biggest concrete gravity dam in Korea. This dam is 97.5 m in height, 447 m in length and 902,000 ㎥ in volume and has 2.75 bullion ㎥ of water storage capacity, 412,000 KW power generation capacities and 616 million ㎥ of flood control capacity.
Hoengseong Multi-Purpose Dam is 48.5 m in height and 205 m in length, and has 87 million ㎥ of water storage capacity and 10 million ㎥ of flood control capacity. This dam features a concentrated water shield wall and stone-built dam, and construction was completed in November 2000, 7 years after commencing in December 1993.
The Andong Multi-purpose Dam is a rockfill type dam with a water blocking core in the center that is 83 m in height, 612 m in length, and 4.014 million ㎥ in volume and stores water of 1,248 million ㎥.
The Namgang Multi-purpose Dam was completed in Oct. 1967, but reinforcement construction was necessary to expand the flood control capacity and the industrial water supply capacity, and was completed in Nov. 1999. This dam is a water shield wall type of dam and is 2,285 k㎥ in area, 34 m in height and 1,126 m in length.
The Imha Multi-purpose Dam, constructed at 18 km upper point from the start of Banbyeon stream, which is the first tributary stream of Nakdong River, is a rockfill type dam that is 73 m in height, 515 m in length and has a storage capacity of 595 million ㎥ With a flood control capacity of 80 million ㎥. The construction of this Dam began in December, 1984 and was completed 7 years and 6 months later in May, 1992.
This Dam is a concrete gravity dam that is 96 m in height, 472 m in length and 891,000 ㎥ in volume. This dam boasts a water storage capacity of 790 million ㎥ and a basin area of 925 Km2. Notably, it was designed with a consideration to the local characteristics of the natural terrain to make the best use of the provided elevation difference for canal system power generation.
It has been built to solve the problem of water shortages in Busan, Ulsan and Masan areas. It will also prevent damage to the rice paddies of the Gimhae plains caused by the seawater intrusion into Nakdong River during dry spells. This 2,230 m-long barrage has 10 water gates and one lock gate that is the biggest in Asia. On top of it is a four-lane road. It has made a significant contribution to easing the water shortage problems in the Nakdong River area, reclaiming 330 ha of land and reducing the transportation distance between Busan and Jinhae by 10 km.
Milyang multipurpose dam is located in Danjang-myeon, Milyang-gun, Kyeongsangnam-do. It is constructed in order to reduce flood damage around Nakdong rive, generate power, and provide water resource for Milyang, Yangsan and changryeong.
The height of dam is 89m, length is 535m, and pondage is 73.6million ㎥. Construction work began in Nov. 1991 and completion ended in 2001. Flood control capacity is 6million㎥, it reduces flood damage in downstream of Nakdong river, and generates 7.0GWh. Also, it provides stable water for downstream, so it helps to improve water quality.
The Daecheong Multi-purpose Dam is a concrete and rockfill combined type dam that is 72m in height, 495m in length and 1,234 million ㎥ in volume. This Dam is divided into a main dam that has a water storage capacity of 1.49 billion ㎥ and a regulation dam. In the region of the main dam, there are three saddle dams that prevent the overflow of water from the reservoir. Upon the completion of Daecheong Dam, the damage caused by flood and salty water on the crops in downstream area has been significantly reduced.
The Seomjingang Multi-purpose Dam, the first of its kind in korea, is a concrete gravity dam that is 64 m in height, 344.2 m in length and 410,000 ㎥ in volume. This dam also has a hydropower plant, a 6,216 m-long water collection tunnel for the power plant and a 800 m-long tunnel for the supply of agricultural water.
The Juam Multi-purpose Dam has been built to solve the water storage problems in the Honam area including Gwangju, Yeosu, Suncheon and Gwangyang. Maing dam, rockfill dam, is 58 m in height, 330 m in length, 457 million ㎥ in water storage capacity and 60 million ㎥ in flood control capacity. It also has a rockfill regulation dam that is 99.9 m in height, 562.6 m in length, 250 million ㎥ in water storage capacity and 20 million ㎥ in flood control capacity. Its power generation capacity is rated at 22,500 kW.
The Buam Multi-purpose Dam was built as part of the government plan for the construction of medium-sized dams. It is located in the Jikso stream in the Byeonsan Peninsular National Park and has a water storage capacity of 41.5 million ㎥. It ensures A stable water supply of 35.1 million ㎥ to the west coast area, including Buan and Gochang, and also reduces flood damages in the lower reaches of Jikso stream.
Boryeong multipurpose dam is built to provide city water and industrial water for 2 Sis and 5 Guns in Middle East of South Korea. Construction work began in Dec. 1991 and ended in Jul. 2000.
The pondage of the present dam is 116.9million㎥, height is 50m, length is 291m. It provides water for Boryeong-si, Seosan-si, Taean-gun, Dangjin-si, Hongseong-gun, Seocheon-gun and Yesan-gun and is located in Wungcheoncheon in Boryeong-si in Chungcheongnam-do and is close to Daecheon swimming beach.
Jangheung multipurpose dam, located in Jicheon-ri, Busan-myeon, Jangheung-gun, is constructed to prevent the flood damage and water supply for nine cities and counties in Jeollanam-do. It’s height is 53m, length is 403m, and pondage is 191million㎥. It's master plan is notified in Dec. 1996, and construction work began in Nov. 1997 and ended in 8th of June, 2006. In accordance with construction of Jangheung multipurpose dam, it was possible to provide 127million㎥ of clean water annually for Jangheung and the southwest area including Mokpo, Sinan, Muan, Yeongam, Gangjin, Wando, Haenam and Jindo.
Yongdam multipurpose dam is located in Jinan area in Jeollabuk-do, where is famous for it’s beautiful and clean nature. It’s height is 70m, length is 498m, and pondage is 815million㎥. Construction work began in Dec. 1990 and ended in Oct. 2001. Along with construction of Yongdam multipurpose dam, it was possible to provide 492million㎥ of clean and stable water annually for Jeonju and the west sea development area including Iksan, Gunsan, Gimjea and Gunjang industry plant area. It contains 137million㎥ of water in flood, and reduces flood damage in middle and downstream and produces green power of 198.5GWh, save 10.7 billion won as substituting energy. In addition, it provides river-holding water stably in dam downstream, thus helps to improve water quality around that area.
As Korea’s water resources are dominated by intense summer rainfall, it is necessary to prevent floods as well as to secure stable water supply through continuous construction of dams. As construction of a dam normally takes at least 10 years, it needs to be implemented based on a multi-dimensional and long-term perspective of demand for water.