Guida
Yanba Dam is a multi-purpose dam located in Nakanoeru Town, Agatsuma District, Gunmed Prefecture, built on the middle reaches of the Agatsuma River, a major tributary of the Tone River. It officially began operations on April 1, 2020. As a gravity concrete dam with a height of 116 meters, it serves critical roles in water supply for the Kanto region (including Tokyo and surrounding prefectures), flood control, and hydroelectric power generation. The reservoir created by the dam is named 'Lake Yanba Agatsuma.' The sheer scale of the structure combined with the surrounding pristine natural environment makes it a captivating destination for visitors.
The construction plan for Yanba Dam was based on the 'Tone River Improvement Plan' announced in 1952. It was a project of immense historical significance, involving substantial investment to address water shortages in the Tokyo metropolitan area and prevent flood damage. The project underwent a long process of negotiation and social discussion regarding its necessity and impact on the local community. In 2024, the dam's design and structural excellence were officially recognized with the prestigious Design Award from the Japan Society of Civil Engineers.
The dam's structure itself is a marvel. The use of radial gates for the main gates allows visitors to feel the immense scale of the engineering up close. The vast surface of Lake Yanba Agatsuma, framed by surrounding mountains, provides a highly photogenic landscape. With a crest length of approximately 290.8 meters, the dam stands as a testament to modern civil engineering. Additionally, the Yanba Power Station located downstream utilizes the water flow for sustainable hydroelectric energy production.
The area offers a different charm in every season. The scenery is particularly stunning when the lake surface is calm or when the surrounding mountains change colors. In summer, seasonal activities such as tours via amphibious buses are often available. Please note that certain areas, such as the 'Yanba Observatory,' may have restrictions or closures during winter. We recommend checking the latest information before your visit. Daytime visits are ideal for capturing the clear reflections on the lake and the sharp details of the massive concrete structure.
Visitors can enjoy various activities to immerse themselves in nature. Depending on the season, you can experience the area through sightseeing boat cruises or unique amphibious bus tours. There are also facilities where you can learn about the history and technical roles of the dam, making your visit both an educational and recreational experience.
The area around the dam features several facilities designed for regional revitalization. At the 'Michi-no-Eki Yanba Furusato-kan' (Roadside Station), you can enjoy local specialties and gourmet food. There are also well-maintained observation points to enjoy the view of the lake. Visiting these spots alongside the dam allows for a deeper understanding of the local community's history and its evolution through the dam construction process.
As the area is rich in nature, comfortable walking shoes and practical clothing are highly recommended. If you plan to participate in seasonal activities or walk around the lake, prepare for potential weather changes. Please respect local rules and safety guidelines when visiting the dam facilities and surrounding natural areas.