Kurobe Dam: The Tallest Dam in Japan

Because of inspiration of the natural wonders of the world and of necessity for development, there are now also wonders in the world that are made by the hands of man. Certain structures that were created by the minds of human beings and made by the hands of people leave some in awe. These structures are deemed so great because most people would not have imagined its concept to actually come alive. Furthermore, these structures were so hard, tedious, and long to make that some people would have deemed its completion to be impossible or futile. One of these structures is the Kurobe Dam.

Facts: Location, Weather, Tours, Kurobe Alpine Route

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Also known as the Kuroyon Dam, the Kurobe Dam is located in Toyama Prefecture, Japan. It is a dam with an arch of varying radius. Standing on the Kurobe River, this dam is made to support the 335 MW Kurobe No. 4 Hydropower Plant. This beauty is operated and owned by Kansai Electric Power Company.

Standing at 186 meters, which is equivalent to 610 feet, the Kurobe Dam is the tallest or highest dam in the country. Its construction began in the year 1956 and ended in the year 1963. The cost for building this dam amounted to 51.3 billion yen. The structural aspect of this dam is considered an engineering feat for Japan when the Second World War just ended due to its difficulty to design and construct and to the rapid growth of the country.

Having taken 7 years to complete, several difficulties and challenges were met in the making of this dam. In this process, 171 people lost their lives during the construction of the Kurobe Dam. At present, this dam welcomes more than 1 million tourists every single year. One of the many features of the dam is its observation deck wherein visitors are treated to a magnificent view of gushing water. As a result of this water action, a misty cloud of spray is created, making the dam look mystical.

The arch of the Kurobe Dam contrasts the beauty of nature of the Northern Alps. Being able to see the two different views together in harmony makes one feel in awe of how the wonders of man adapted to the wonders of nature. Some of the pieces of nature that accentuate the beauty of the dam include the huge and old tree Kurobe, stumps of other big trees, alpine plants, and beech tree forests that consists of cold springs.

The dam also contains trails that let guests enjoy forest bathing. An excursion boat is also offered to tourists who wish to go around Lake Kurobe. This boat ride takes around 30 minutes to complete and lets passengers see a magnificent view of the Northern Alps, which also includes a view of the Tateyama mountain range. For a more adventurous route, one may also opt to take walking courses that let visitors be one with nature as they walk under sunbeams that filter through the leaves.

The famous dam is also situated in the Tateyama Kurobe Alpine Route. A well-known mountain sightseeing route, the Tateyama Kurobe Alpine Route begins in the Omachi hot spring village located in Nagano Prefecture and goes all the way to Tateyama in Toyama Prefecture. Upon reaching Tateyama, guests can also enjoy riding the trolleybus, cable car, and aerial tramway.

These transportation means are the way to go to the Kurobe Dam. It is important to wear appropriate clothing based on the temperature of the area as well as the weather conditions. Because the dam is located in a mountain area that is 3,000 meters high, the weather up there may be too harsh or cold.

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The purpose of the Kurobe Dam is to support a hydropower plant that serves as the regular supplier of electricity to the region of Kansai. The dam also serves as a major tourist attraction along the alpine route. The most sought-after scene of the dam is when it discharges water in a spectacular manner that leaves guests in awe of its beauty. Water gets discharged through the gates of the dam on a daily basis from late June to mid-October.

A long and steep flight of stairs can be found at the eastern end of Kurobe Dam. The stairs lead visitors up to the mountain slope that is now covered by concrete. From there, visitors can see an aerial view of the dam as well as its environment. The trip up the stairs may take around 15 minutes to climb.

Sightseeing boats that take visitors around Kurobe Lake can be availed from early June to early November. The boat ride takes about 30 minutes and lets visitors see the beauty of the lake where the Kurobe Dam can be found. The sightseeing boat ride is also said to be at the highest altitude in the country.

Some people may confuse the Kurobe Dam to the Kurobe Gorge Railway, which is basically a railway line. This railway is located far down the valley from Kurobe Dam. The Kurobe Gorge Railway was initially built for the purpose of helping in the construction of Kurobe Dam. However, at present, this railway line is utilized for tourism purposes. It also no longer connects to the Kurobe Dam.

This railway line can be accessed by visitors coming from the coast of the Sea of Japan. One may also hike along the gorge from the railway all the way to the dam. However, this hike is definitely not for beginners or even for intermediate hikers. This is because trekking this line may take around 2 to 3 days to complete and the trails are challenging.

It is important to take into account the alpine weather when going to the Kurobe Dam. If one would like to go on a certain season, it is also important to take note of that in order to maximize one’s visit to the Kurobe Dam. Going to the Kurobe Dam via the Tateyama Kurobe Alpine Route is strongly suggested. The alpine route is typically only open from mid-April to November.

Unfortunately, during the middle and late parts of the winter season, the snowfall is too deep and heavy to let tourists visit the area of Kurobe Dam. The first and foremost concern of the administration is the safety of its guests, after all. The best time to visit the Kurobe Dam is during the spring and the fall season, when flowers are in full bloom and the leaves change into a vibrant hue, respectively.

History and Construction of Kurobe Dam

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The Kansai Electric Power Company was established in the year 1951 to serve as the supplier of electricity for the whole Kansai Region. However, just after a short time since its formation, the region experienced and suffered from drought. Because of this drought, power rationing occurred.

With the rapid growth of the country post-Second World War, the power company had to generate more electric power for the Kansai Region. At the time, the generating capacity of the company was not enough to supply the needs of the region. Hence, a series of hydrological and geological research of the Kurobe River and Gorge was conducted. The result of this series of studies is the need to construct the Kurobe Dam, as was announced in the year 1955.

The construction of the dam started in July of the year 1956. One of the first problems that surfaced during construction was the transportation of materials to the site. Because there is only a single tiny railway that passes through the narrow gorge, the efficiency of the transportation of materials was compromised. Hence, it was proposed to build the Kanden Tunnel, running at 5.4 kilometers in length, under Mount Tate. This tunnel would enable the transportation of materials from Omachi to the site.

Another problem arose in building the tunnel due to a huge fracture zone in the rock. After solving these problems, the first concrete placed for the dam was accomplished in September of the year 1959. Almost a year after this, which was in the month of October the following year, the reservoir began to fill.

The construction of the Kurobe No. 4 power station was done completely underground. This action was based on the goal of protecting the station from common avalanches that occur in the gorge. Another purpose of this decision was to conserve nature. Two of the Pelton turbines of the power station with an initial capacity of 154 MW started running by January of the year 1961.

More than a year later, the third turbine began running in August of the year 1962. Less than a year after that, the dam was finally completed in June of the year 1963. The final cost of this project was 142.5 million yen at the time, which is equivalent to 51.3 billion yen today. The capacity of the station was increased to 335 MW in the year 1973 when a fourth turbine was installed.

This additional turbine cost 5 million yen at the time, which is now equivalent to 1.4 billion yen. Voith manufactured the first two turbines while Hitachi manufactured the last two. Because of the Kurobe Dam, the first 275kV transmission system was developed. This system enabled the transfer of electricity despite longer distances.

Specifications of the Tallest Dam in Japan

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Standing at 186 meters or 610 feet high, the Kurobe Dam is 492 meters or 1,614 feet long. The dam has a varying radius dome or arch. Its base has a width of 39.7 meters or 130 feet while its crest has a width of 8.1 meters or 27 feet. Kurobe Dam consists of 1,582,845 cubic meters or 2,070,283 cubic yards of concrete.

Two “wing” dams that also serve as the abutments support Kurobe Dam on both sides. The left bank has a length of 69 meters or 226 feet while the right bank has a length of 56 meters or 184 feet. The dam houses a reservoir that has a volume capacity of 199,285,175 cubic meters or 260,655,168 cubic yards. 148,843,000 cubic meters or 194,679,000 cubic yards of this capacity is used as live, active, or “useful” storage.

With a surface area of 3.49 square kilometers or 1.35 square miles, the reservoir also contains a catchment area of 188.5 square kilometers or 72.8 square miles. The spillway of the dam is situated on its crest. This spillway contains ten uncontrolled openings, with each having a width of 11.5 meters or 38 feet. The maximum discharge of these openings is 906 cubic meters per second or 32,000 cubic feet per second.

The orifice of the dam also consists of three other openings. These include two pipes with a diameter of 1.5 meters or 4.9 feet that can discharge a maximum of 88 cubic meters per second or 3,100 cubic feet per second for each pipe. The third pipe with the same dimensions can discharge a maximum of 44 cubic meters per second or 1,600 cubic feet per second. The crest elevation of Kurobe Dam is 1,454 meters or 4,770 feet above sea level. On the other hand, the normal operating level of the reservoir is 1,448 meters or 4,751 feet. Low level of the reservoir is at 1, 338 meters or 4,390 feet.

The average annual generation of the Kurobe No. 4, the power station of the dam, is 1 billion kWh. The station itself has a height of 33 meters or 108 feet, a width of 22 meters or 72 feet, and a length of 117 meters or 384 feet. Water is served to the power station via the penstock that has a length of 10,909.6 meters or 35,793 feet.

Going to the Dam in Spring and Autumn, Not Winter

The Kurobe Dam is truly an engineering feat and wonder. The best place to visit the dam is during the spring season and the autumn season. The spring season brings the blooming of several flowers in the areas, providing a picturesque view. On the other hand, the autumn or fall season changes the color of the leaves in the area into a vibrant hue, which accentuates the whiteness of the water of the dam. However, due to safety reasons, it is not advisable to visit the dam during the winter season.