Why Obara Dam Was Built
A Major Project Triggered by Severe Flooding
The development of Obara Dam was accelerated following the July 1972 heavy rains, a disaster that caused extensive flooding in the Hii River basin. Large areas, particularly around Matsue, were inundated and suffered serious damage.
In response, the Hii River and Kandogawa River Comprehensive Development Project was launched to manage the two river systems together and reduce the risk of future flooding. Obara Dam became one of the project’s key facilities.
Three Important Roles of Obara Dam
Flood control: The reservoir temporarily stores large amounts of rainwater, helping reduce flooding downstream during periods of heavy rainfall.
Protection of the river environment: The dam helps maintain a stable water supply, supporting the habitats of plants and animals along the river.
Water supply: Obara Dam supplies up to 38,000 cubic meters of water per day to areas including Matsue and Izumo.
Through these functions, Obara Dam supports disaster prevention, environmental conservation, and everyday life in the region.
Sakura Orochi Lake
A Beautiful Reservoir Inspired by Nature and Japanese Mythology
The reservoir created by Obara Dam is called Sakura Orochi Lake. Its name combines two important elements of the Hii River region: the Yamata-no-Orochi, the eight-headed serpent from Japanese mythology, and the cherry blossoms that are beloved throughout the area.
The name also expresses the hope of calming the legendary Orochi through the dam while giving the reservoir a friendly and memorable identity connected with the local landscape.
The scenery around the lake changes beautifully throughout the year. Spring brings cherry blossoms, summer brings lush green mountains, autumn fills the landscape with colorful foliage, and winter creates a quiet world of snow.
A Center for Sports and Outdoor Recreation
The area around Sakura Orochi Lake has been developed with a variety of sports and recreational facilities. A cycling road-racing course runs around the lake, while facilities for boating and other water sports are also available.
These facilities have helped make the lake a venue for sporting competitions and community events, attracting participants and visitors from outside the local area.
Major Events Around Sakura Orochi Lake
Trail Running Events: Participants run through a varied course featuring mountain villages, forest paths, and streams.
Regatta and Walking Events: These events make use of the lake and its scenic surroundings for outdoor recreation and sports.
Triathlon Events: Swimming, cycling, and running are combined in full-scale competitions held in the beautiful natural setting.
Sakura Orochi Lake Festival: One of the area’s major local festivals, featuring regional food, activities, and hands-on experiences for visitors.
These events provide opportunities for local residents and visitors from across Japan to enjoy the lake while connecting with the surrounding community.
Nearby Attractions
Roadside Station Orochi no Sato
Located along National Route 314, Roadside Station Orochi no Sato is a convenient stop for travelers exploring the Obara Dam area. Visitors can purchase fresh locally grown agricultural products and regional specialties, as well as enjoy local dishes at the farmers’ restaurant.
It is an ideal place to take a break during a drive through the mountains of Unnan.
Saishiro Onsen Chojanoyu
Approximately 5 kilometers from Obara Dam, Saishiro Onsen Chojanoyu is a relaxing hot spring facility surrounded by nature. Its open-air bath, featuring stones from the Hii River, creates a peaceful atmosphere where visitors can enjoy a traditional Japanese hot spring experience.
Soaking in the warm water while surrounded by the mountain landscape is a wonderful way to relax after exploring the area.
Okuizumo Tane Natural History Museum
Okuizumo Tane Natural History Museum is a unique museum built around the theme of the evolution of the universe and the history of life. Visitors can discover dinosaur fossils and a wide range of exhibits related to natural history.
The facility also offers accommodation, and special nighttime programs have become a popular feature for visitors who want to enjoy a different kind of museum experience.
The Hii River and Its Long History
Obara Dam stands on the Hii River, which rises at Mt. Funatsu on the border between Shimane and Tottori prefectures. The river flows through Lake Shinji and Lake Nakaumi before reaching the Sea of Japan.
The Hii River has supported agriculture and local communities for centuries. At the same time, it was historically known as a powerful and unpredictable river that repeatedly caused flooding.
During the Edo period, the development of tatara ironmaking also affected the river. Soil and sediment generated by iron production flowed into the river, contributing to changes in its course and increasing the risk of flooding in some areas.
This long history of flooding explains why river management and flood-control measures have been an important issue in the Hii River basin for generations.
Obara Dam as a Tourism Destination
A Dam Open to the Local Community
Obara Dam has been developed as a community-oriented dam, with facilities and programs that allow visitors to experience the dam and its surrounding environment.
Viewpoints and visitor facilities provide opportunities to appreciate the impressive scale of the structure. Depending on the schedule, visitors may also be able to join tours or special programs that offer a closer look inside the dam.
The surrounding area is also suitable for activities such as cycling and water sports. Riding beside the lake offers a refreshing way to experience the mountain scenery, while the wide expanse of water provides a striking setting for outdoor recreation.
The Spectacle of Water Release
One of the most impressive sights at Obara Dam is the annual crest gate water release. A tremendous volume of water rushes down from the dam, creating a powerful spectacle that allows visitors to appreciate the enormous scale and engineering of the structure.
For those interested in dams, engineering, and the relationship between infrastructure and nature, this is a particularly memorable experience.
A Scenic Journey Through Nature, History, and Mythology
Obara Dam is an important piece of infrastructure built to protect communities along the Hii River, but it is also a fascinating destination where nature, history, mythology, and outdoor recreation come together.
At the heart of the area, Sakura Orochi Lake offers beautiful seasonal scenery, while the surrounding region provides opportunities for cycling, water sports, festivals, hot springs, and local cuisine.
The connection with the Yamata-no-Orochi legend adds another layer of interest to the journey. Exploring the upper Hii River region allows visitors to experience not only the beauty of the mountains but also the myths and traditions that have shaped the cultural identity of Izumo.
Whether you want to enjoy a peaceful landscape, take part in outdoor activities, discover local history, or explore the world of Japanese mythology, the Obara Dam area offers a memorable experience in the mountains of Shimane.