SAKIGAKE管理人 Introduction
On July 3, 2021, a debris flow struck the Izuyama district of Atami City, Shizuoka Prefecture, claiming 28 lives and leaving more than 130 homes damaged. While record-breaking rainfall was the immediate trigger, the greatest shock this disaster delivered to society was the revelation that “at the origin point of the debris flow, there was an embankment that had been illegally constructed.”
The Atami debris flow was not treated simply as a natural disaster. Instead, it became the catalyst for a major change in the direction of government response and legislative reform, as a “man-made disaster in which human factors magnified the scale of the damage.” This article looks back at those events and considers how the lessons learned can be applied to corporate compliance and risk management.
The Embankment That Caused the Debris Flow
The origin point of the debris flow was an embankment of approximately 54,000 cubic meters located upstream in the Izuyama district. This embankment had been formed when a land developer improperly piled up soil containing industrial waste, and subsequent investigations revealed that adequate drainage measures and safety management had not been implemented.
As rainfall at record levels saturated the embankment with moisture and loosened the ground, the entire embankment collapsed at once, sweeping up soil downstream and striking residential areas as a debris flow. Expert investigations have indicated that if the embankment had not existed, the scale of the damage could have been substantially smaller.
Challenges Left in the Administrative Licensing Process
Another reason this disaster attracted criticism was the fact that this embankment had been constructed with permission granted under a Shizuoka Prefecture ordinance. Investigations revealed significant discrepancies between the content of the original permit application and the actual construction carried out, and that post-construction supervision and patrols by the authorities had been insufficient.
In other words, the fundamental problem was not that “there were no rules,” but that “even though rules existed, they were not being enforced effectively.” This is an important lesson for thinking about corporate compliance systems. The Atami debris flow brought home the reality that the existence of regulations and manuals is a separate matter from whether they are actually being followed and functioning.
The Embankment Regulation Act — How Did the System Change?
In the wake of this disaster, the national government enacted the “Act on Regulation of Residential Land Development and Specific Embankment Structures (Embankment Regulation Act)”, which came into force in May 2023. The law standardizes regulation of embankments — previously governed by different ordinances in each prefecture — under nationally unified standards and with strengthened penalties.
Specifically, areas where there is a risk of dangerous embankment construction are designated as “regulated zones,” and strict penalties of up to three years’ imprisonment or a fine of up to ten million yen have been established for unauthorized construction or embankment activities that fail to meet safety standards. Additionally, a system has been put in place to ensure that responsibility for safety management carries over even when land ownership changes.
Implications for Corporate Compliance and Risk Management
The lessons of the Atami debris flow contain perspectives relevant to the risk management of all companies, not just those in the construction and real estate industries.
First, the recognition that having “obtained a permit” and being “safe” are not the same thing. Responses aimed solely at satisfying regulatory requirements risk overlooking fundamental risks. What is required is a posture of independently verifying actual safety, rather than merely the form of legal compliance.
Second, understanding land and facility risks within the supply chain. Knowing what kind of construction history the sites of a company’s own locations or those of business partners have is directly linked to reducing operational risk.With the Embankment Regulation Act now in force, checking the designation status of regulated zones also becomes an important factor in future site selection and disaster risk assessment.
Third, establishing internal control mechanisms to prevent the “hollowing out” of rules. Rules without implementation are meaningless. In corporate contexts as well, continuously checking the gap between regulations and actual practice through periodic internal audits and on-site inspections is critical.
Introducing a Related Solution
For those looking to grasp warning signs of landslides and debris flows like the one in Atami in real time, we would like to introduce a disaster prevention solution handled by SAKIGAKE JAPAN.
DIPPS Cloud | Portable Landslide Monitoring Stake System
“DIPPS Cloud” is a portable monitoring stake system that detects ground anomalies simply by inserting stakes into slopes or cliffs, and notifies the cloud wirelessly.Even on steep slopes and in mountainous areas like those in Atami, it enables continuous 24-hour remote monitoring of on-site conditions without the need for specialized technicians on-site. When an anomaly is detected, the management screen changes from green to red, and an instant email notification is sent to the relevant parties.
- Easy installation: No large-scale construction required — just insert the stake into the ground to start
- Centralized cloud management: Monitor multiple locations on a single screen from a PC or smartphone
- Works even outside mobile coverage: Mountain areas covered via satellite communication and Starlink connectivity
- Approximately 2-year battery life: Continuous monitoring with minimal maintenance burden
“Even with rules in place, what couldn’t be prevented without monitoring —” building on the lessons of Atami, this is a solution designed to detect anomalies at the warning sign stage and enable rapid evacuation decisions and emergency response.
For details and inquiries, see below:
DIPPS Cloud Product Page
Conclusion
The Atami debris flow left society with a heavy lesson — “systems without implementation are meaningless” — at the cost of 28 lives. The enactment of the Embankment Regulation Act represents one step toward reflecting that lesson in the system.
Companies, too, are called upon to reframe compliance — not merely as “rules to be followed,” but as a mechanism for continuously verifying whether those rules are actually functioning. As professionals in corporate disaster prevention consulting and disaster risk management, SAKIGAKE JAPAN is fully committed to supporting your disaster preparedness efforts.