Guide
The Former Ominato Water Source Water Facility is a historic water facility designated as an Important Cultural Property, located in the Uda-cho and Sakuragi-cho areas of Mutsu City, Aomori Prefecture. Completed in October 1909, this dam served as a core component of the water supply system for the former Imperial Japanese Navy's Ominato Naval District. Despite its scale—7.9 meters in height and 26.5 meters in length—it holds immense technical value as Japan's first attempt at a thick-arch stone dam. It was constructed to control the flow of the Udagawa River, which originates from Mount Kamuga.
This facility is a significant relic demonstrating the introduction of modern hydraulic engineering during the Meiji era. Since its completion in 1909, it functioned as vital infrastructure for the Ominato Naval District. Later, it was managed and operated by the town of Ominato from 1946 to 1976. The structure serves as a physical testament to the region's modernization process and its historical role as a strategic military base. Today, it is protected as an Important Cultural Property due to its historical and technical significance.
The most striking feature is the four spillways (overflow outlets) built into the stone structure. These outlets form beautiful comb-shaped arches, creating a breathtaking sight as water cascades through them. The combination of the structural elegance of the arches and the robust, heavy stone construction makes it a fascinating site for observing early examples of thick-arch stone dam technology in Japan.
As an outdoor dam, the scenery changes with the seasons. During the summer or periods of heavy rain, you can observe the powerful flow of water cascading through the four comb-shaped arches. In winter, the stone structure is often blanketed in snow, offering a serene and starkly beautiful sight. For the best visibility of the stone textures and the intricate arch shapes, visiting during bright daylight hours is highly recommended.
Visitors can visually experience the advanced civil engineering techniques of the Meiji era. It is a unique opportunity to observe how historical stone-stacking methods were used to create stable arches designed to control natural river flows, providing a deep look into the structural characteristics of early modern hydraulic architecture.
The facility is located near Uda-cho and Sakuragi-cho in Mutsu City. The surrounding area is rich in nature, featuring the scenic headwaters of the Udagawa River flowing from Mount Kamuga. It is a perfect stop for those exploring the historical landmarks and cultural heritage sites within Mutsu City.
This is a public space and a cultural property; there are no admission fees or payments required to view the facility.
English-language signage and staff support are very limited. We recommend bringing a translation app or studying the history in advance.
No prior reservation is required to visit.
As the facility is located near a natural riverbank and the terrain may be uneven, we strongly recommend wearing comfortable walking shoes suitable for outdoor paths.
There are no specific restrictions on photography, but please be mindful of the natural environment and ensure your safety while taking photos.
The area around the dam features natural terrain with some uneven surfaces and steps. It is not fully barrier-free.
As this is a designated Important Cultural Property, please do not touch the stone structures or any equipment, and avoid any actions that could cause damage to the site.