Tataragi Dam is a hydroelectric dam in Asago City, Hyogo Prefecture, set amid the quiet mountains of the Tajima region. Built on the Tataragi River, part of the Maruyama River system, it is operated by Kansai Electric Power and serves as a key component of a large-scale pumped-storage hydroelectric power system.
Tataragi Dam is a rockfill dam standing 64.5 meters high. Its upstream face is covered with asphalt, a design known as an asphalt-faced rockfill dam. Japan’s first dam of this type was Otsumata Dam in Fukushima Prefecture, introduced in 1968. Tataragi Dam was the first asphalt-faced rockfill dam built in western Japan.
The dam forms Tataragi Reservoir and works together with Kurokawa Dam on the Ichikawa River, located upstream, to support pumped-storage hydroelectric generation. The wider Okutataragi Power Station has a maximum generating capacity of approximately 1.93 million kilowatts, making it one of Japan’s largest hydroelectric power facilities.
During Japan’s period of rapid economic growth, electricity demand across the Kansai region rose sharply. Urbanization centered on Osaka and the expansion of the Hanshin Industrial Zone placed increasing pressure on the region’s power supply. Kansai Electric Power therefore needed to develop new facilities capable of meeting this growing demand.
Pumped-storage hydroelectric power attracted particular attention because it could help meet peak electricity demand during the day. An earlier proposal called for an upper reservoir in Kyoto Prefecture and a lower reservoir near Wakasa Bay. However, environmental concerns and strong opposition led to the plan being abandoned. The company subsequently selected the present Tataragi Dam site as an alternative, and construction began in 1970.
Tataragi Dam was completed in 1974, becoming part of a major hydroelectric power development in Japan. Following the oil crisis, interest in hydroelectric power increased, and additional construction was undertaken in 1979 to expand generating capacity. The expansion brought the facility’s capacity to approximately 1,932,000 kilowatts.
Okutataragi Power Station is a major pumped-storage facility operated by Kansai Electric Power. It uses Kurokawa Dam as its upper reservoir and Tataragi Dam as its lower reservoir, taking advantage of an effective hydraulic head of 387.5 meters. The station has a generating capacity of 1,200,000 kilowatts.
One notable feature is that the power-generation facilities are located entirely underground, approximately 100 meters below the surface. This underground design allows the large-scale power station to operate within the mountainous landscape.
Since 1979, Kurokawa Dam has also served as a water source for Hyogo Prefecture’s municipal water supply program. It supplies drinking water and industrial water to Himeji City and other areas, giving the wider dam system an important role beyond electricity generation.
The area downstream of Tataragi Dam includes Asago Arts Forest, a green park that combines natural scenery with contemporary art. The grounds contain the Asago Arts Forest Museum, an unusual cultural facility located directly below a dam. Visitors can also explore an outdoor sculpture park and the Asago City Asago Historical and Folklore Museum.
Two hotels with hot spring facilities stand along the Tataragi River, offering a relaxing place to stay amid the mountain scenery. Visitors interested in the engineering behind the dam can also arrange a tour of Okutataragi Power Station in advance, subject to availability.
A running event that circles the reservoir is held annually on the first Sunday in June. Guided power station tours are also organized in connection with the event, attracting visitors interested in both outdoor recreation and hydroelectric engineering.
Tataragi Dam and its surroundings are known as a cherry blossom destination in the Tajima region. In spring, the area is celebrated for its many cherry trees, sometimes described collectively as the Thousand Cherry Trees, and attracts visitors for seasonal walks and picnics.
Other well-known cherry blossom destinations nearby include Takeda Castle Ruins and Ritsuun-kyo Gorge. Visiting during the spring flowering season offers an opportunity to enjoy the region’s mountain scenery alongside its historic sites.
Aokura Shrine, known locally as a shrine associated with eye health, is another nearby destination. It can be reached along the network of roads around the reservoir and provides a cultural stop amid the area’s natural surroundings.
Tataragi Dam can generally be reached by car via National Route 312 and National Route 429. A municipal road branching off from the road around the reservoir also provides access toward Kurokawa Dam.
The dam is well placed for exploring other destinations in northern Hyogo Prefecture. The Bantan Expressway and National Route 312 connect the area with historic sites such as Ikuno Silver Mine and the castle town of Izushi, as well as with Himeji and the famous Himeji Castle.
Tataragi Dam offers more than a peaceful reservoir surrounded by mountains. It is an important example of Japan’s hydroelectric engineering, with a distinctive asphalt-faced structure and a major pumped-storage system hidden beneath the surrounding landscape.
Visitors can combine a stop at the dam with contemporary art, local history, hot springs, cherry blossom viewing, and nearby cultural landmarks. For travelers exploring Asago City and the wider Tajima region, Tataragi Dam makes an interesting destination where technology, nature, and regional heritage come together.