The Wakayama Prefecture Sediment Disaster Awareness Center is a disaster-prevention learning facility located in Nachikatsuura, Wakayama Prefecture. It was established following the devastating Kii Peninsula Flood Disaster of 2011, which caused extensive damage throughout Nachikatsuura and other parts of the Kii Peninsula.
The center serves as an important base for research, education, and public awareness concerning landslides and other natural disasters. Visitors can learn about the destructive power of sediment disasters, understand how disaster-prevention infrastructure works, and consider how communities can better prepare for future emergencies.
In September 2011, Typhoon No. 12 brought record-breaking rainfall to the Kii Peninsula. Prolonged heavy rain triggered massive landslides, debris flows, river flooding, and other disasters, resulting in the loss of many lives. Nachikatsuura was particularly severely affected, with large-scale debris flows causing extensive damage across the town.
The center was created to ensure that the lessons of this disaster are not forgotten. By preserving records of what happened and communicating the importance of disaster preparedness to future generations, it plays an important role in the region’s ongoing efforts to build a safer community.
In September 2011, Typhoon No. 12 moved northward across Japan at an unusually slow speed. As a result, enormous amounts of rain continued to fall over the Kii Peninsula for an extended period. In Nachikatsuura’s Irokawa district, total rainfall reached 1,186 millimeters, while Osugi in Tanabe recorded an extraordinary 1,998 millimeters.
The intense rainfall destabilized mountain slopes and caused numerous sediment disasters throughout the region. In Wakayama Prefecture, 61 people were killed or reported missing, including 29 people in Nachikatsuura alone.
The Ichinono district along the Nachi River was especially badly affected. A massive debris flow swept through the area, destroying and carrying away houses and causing catastrophic damage to the surrounding community.
At the center, visitors can learn about these events through large monitors, photographic panels, video materials, and other exhibits. Images recorded during the disaster, aerial photographs, and detailed records of the damage help visitors understand how quickly and powerfully natural disasters can transform a landscape.
The center is a two-story wooden building constructed using abundant amounts of Kishu timber from Wakayama Prefecture. The natural scent and warmth of the wood create a calm and welcoming atmosphere, quite different from the image that visitors might normally associate with a disaster-prevention facility.
The flooring is particularly noteworthy. Special flooring made from compressed cedar has been used to increase its durability. The building therefore demonstrates how local natural resources can be incorporated into modern public architecture.
One of the first things visitors notice after entering is the debris-flow simulation device installed in the atrium. This interactive exhibit uses actual sand and water to demonstrate how debris flows occur and how debris-flow control dams, also known as sabo dams, can help protect communities.
By comparing simulations with and without a sabo facility, visitors can clearly see the difference that disaster-prevention infrastructure can make. The easy-to-understand demonstrations are suitable for both children and adults, making the center an effective place for hands-on disaster-prevention education.
The first floor is primarily designed as an exhibition and learning space for the general public, while the second floor contains research facilities and workspaces for specialists.
Researchers and technical experts from organizations including the Kinki Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism, research institutions, and universities collaborate here on research and technological development related to sediment disasters.
The facility also serves as a base for the Large-Scale Sediment Disaster Countermeasures Technology Center operated by the Kinki Regional Development Bureau. In the event of a major disaster, such facilities can support rapid assessment and response.
The research areas are not generally open to visitors, but knowing that specialists are working behind the scenes adds another dimension to the center. It is not only a museum-like facility but also part of Japan’s broader system for studying and responding to natural disasters.
Another distinctive feature of the center is the opportunity to see actual sabo dams in the surrounding area. Large windows inside the building provide views of nearby disaster-prevention structures, allowing visitors to see how these facilities are integrated into the landscape.
A newer sabo dam with enhanced functions has also been constructed to the west of the center, while large-scale sediment-control facilities have been developed along the Nachi River to the east.
Seeing these real structures after learning about their function through models and demonstrations helps visitors better understand the role of disaster-prevention infrastructure. It is one of the aspects that makes a visit to the center particularly valuable.
Through these exhibits and facilities, visitors can also gain a deeper understanding of what it means to live alongside nature in the Kumano region, where the mountains and rivers provide abundant natural blessings while also presenting potential hazards during severe weather.
Typhoon No. 12 of 2011 developed near the Mariana Islands and gradually moved northward. Because the typhoon traveled so slowly, the Kii Peninsula experienced exceptionally heavy rainfall over a prolonged period.
In Kamikitayama Village in neighboring Nara Prefecture, total rainfall exceeded 1,800 millimeters, an extraordinary amount even by the standards of Japan’s heavy-rain events. In mountainous areas, massive slope failures known as deep-seated landslides occurred, and natural dams formed when landslides blocked rivers in several locations.
In Nachikatsuura, repeated debris flows and river flooding occurred along the Nachi River. Houses, roads, and bridges were washed away, while bridges along the JR Kisei Main Line were also damaged. The disaster caused major disruptions to the region’s transportation network, with some railway services suspended for an extended period.
The disaster was not simply a tragic event of the past. It left important lessons that continue to influence disaster-prevention policies, infrastructure development, and community planning today. At the center, visitors can learn about both the damage caused by the disaster and the subsequent process of recovery and reconstruction.
The Wakayama Prefecture Sediment Disaster Awareness Center is much more than a conventional exhibition facility. It encourages visitors not only to learn about the destructive power of natural disasters but also to consider an important question: How should we respond if a similar disaster occurs in our own community?
Heavy rainfall, landslides, and other natural disasters continue to occur in many parts of Japan. For this reason, the knowledge presented at the center remains highly relevant today. The facility provides an especially valuable learning opportunity for families and students, helping them understand the risks associated with living in areas surrounded by mountains and rivers.
The center can also be incorporated into a sightseeing trip around Nachikatsuura. The surrounding area is home to famous destinations such as Kumano Nachi Taisha Grand Shrine and Nachi Falls, both closely associated with the cultural and spiritual heritage of the Kumano region.
Combining these sightseeing destinations with a visit to the disaster-awareness center offers a broader perspective on Kumano—not only its spectacular scenery and long history, but also the challenges of living alongside a powerful natural environment.
The mountains of Kumano have been revered as sacred places for centuries. At the same time, the region’s steep mountains and abundant rainfall can create dangerous conditions during typhoons and periods of intense rain.
The Wakayama Prefecture Sediment Disaster Awareness Center offers a valuable opportunity to understand both sides of this relationship with nature. By learning about the beauty and blessings of the Kumano landscape as well as its potential dangers, visitors can gain a deeper appreciation of the region and the importance of disaster preparedness.
For anyone visiting Nachikatsuura, the center provides a meaningful opportunity to remember the lessons of the 2011 Kii Peninsula Flood Disaster and consider how those lessons can help protect communities in the future.