When is the Government Liable for Failing to Regulate and Prevent a Landslide in Japan?

Japanese Attorney at Law - Bengoshi L.L.

• 5 min read

Government agencies in Japan are vested with powerful regulatory authority to ensure public safety, from enforcing building codes to overseeing environmental standards. But with great power comes great responsibility. What happens when a regulator is aware of a ticking time bomb—a dangerously unstable construction site, for example—but fails to act, leading to a preventable disaster? Can the government be held financially liable for the consequences of its inaction?

The answer is yes, but the legal path to establishing this liability is a steep one. Under Japan's State Redress Act, a victim must prove not just that the government failed to act, but that its failure was so egregious as to be legally unjustifiable.

This article explores the legal doctrine of liability for regulatory inaction (規制権限の不行使, kisei kengen no fukōshi). Using a case study of a catastrophic landslide from an improperly developed hillside, we will break down the concrete, multi-factor analysis that Japanese courts use to determine when a government's failure to regulate crosses the line from a permissible exercise of discretion to an illegal act requiring compensation.

The Case Study: The Preventable Landslide

To understand the legal principles at play, consider the following representative case, based on the Hiroshima District Court's decision of September 26, 2012.

The Factual Background

A resident lives in a home situated directly below a steep hillside. A developer begins extensive earthworks on the hillside property above, intending to create a large parking and materials yard. The developer brings in massive amounts of soil, piling it on top of a slippery, impermeable industrial sheet left by a previous owner. This creates a visibly unstable, steep slope.

The area is located within a "Land Development Work Regulation Area" designated under Japan's Land Development Regulation Act (宅地造成等規制法, Takuchi Zōsei-tō Kisei Hō, "Takuzōhō"). This designation means that any significant land development requires a permit and must adhere to strict safety standards. The developer, however, has not obtained a permit.

Alarmed by the growing risk of a landslide, the resident formally notifies the prefectural governor, providing details of the unpermitted and dangerous construction and requesting that the governor use his powers under the Takuzōhō to intervene. The governor's office responds in writing, refusing to act. The official reason: the governor's office has concluded that a "parking lot" does not qualify as a "residential lot" (takuchi) under the Act, and therefore, the governor has no legal authority to regulate the construction.

Shortly thereafter, a period of heavy but foreseeable rainfall occurs. The unstable hillside gives way in a massive landslide, completely destroying the resident's home and causing severe injuries. The resident sues the prefecture for damages.

A lawsuit against the government for failure to act is filed under Article 1 of the State Redress Act (国家賠償法, Kokka Baishō Hō). This article holds the state or a local public entity liable for damages caused when a public official, in the exercise of public power, illegally inflicts harm upon a citizen. Crucially, Japanese courts have long held that the "exercise of public power" includes not only wrongful actions but also the illegal failure to act when there was a duty to do so.

The central challenge for any plaintiff is to prove that the government's inaction was "illegal" (違法, ihō). This is a high bar. Courts recognize that regulators have discretion (sairyō) and cannot police every potential risk. A mere failure to act is not, by itself, illegal.

The standard established by the Japanese Supreme Court is that regulatory inaction is only illegal if the failure to exercise the vested authority "deviates from the permissible scope of discretion and is found to be grossly lacking in reasonableness."

This is an abstract standard, but through decades of case law, courts have developed a concrete, four-factor analysis to apply it to specific facts. A plaintiff must effectively demonstrate "yes" to each of the following four questions.

1. Was There a Grave and Specific Danger?

First, the court assesses the objective risk. The danger cannot be a vague, generalized concern. It must be a specific and serious threat to life, body, or property.

In our case study, this factor is clearly met. An enormous, unstable mass of earth piled on a slippery industrial sheet on a steep slope directly above a person's home constitutes a grave and highly specific danger of a landslide.

2. Was the Harm Foreseeable to the Regulator?

Second, the plaintiff must prove that the regulator knew, or should have known, about the specific danger. This is the foreseeability (予見可能性, yoken kanōsei) requirement.

Here, foreseeability was undeniable. The resident had provided explicit, written notification to the governor's office detailing the dangerous and unpermitted work. Furthermore, a prefectural official had visited the site and personally observed the hazardous conditions. The regulator was not just constructively aware of the risk; it was actually aware.

3. Was It Possible for the Regulator to Avert the Harm?

Third, the plaintiff must show that the regulator had the power to prevent the disaster. This possibility of aversion (回避可能性, kaihi kanōsei) has two components: legal possibility and factual possibility.

Legal Possibility: Did the regulator have the legal authority to intervene? This was the government's central defense. The governor claimed that because the intended use was a "parking lot," the land was not a "residential lot" (takuchi) as defined by the Takuzōhō, and therefore he had no jurisdiction.

This defense collapses under scrutiny. Article 2 of the Takuzōhō defines a takuchi very broadly as any land other than farmland, forest land, and land used for public facilities like roads and parks. A privately owned parking lot or materials yard clearly falls outside these exceptions and is, therefore, legally a takuchi subject to the Act's regulations. The governor's interpretation was a clear mistake of law. Because the construction was unpermitted and dangerous, the governor had the explicit legal authority under Article 14 of the Act to issue a stop-work order or an order to implement corrective safety measures.

Factual Possibility: If the governor had used his legal authority, could the landslide have been prevented? The answer is almost certainly yes. A stop-work order would have prevented the slope from becoming even more unstable. An order to implement proper engineering solutions, such as installing retaining walls and ensuring proper drainage, would have stabilized the existing earthworks.

4. Was Government Intervention Necessary?

Finally, the court considers whether the government's intervention was truly necessary, or if the victim could have reasonably been expected to protect themselves. This is a question of necessity/subsidiarity (補充性, hojūsei).

In the face of a potential landslide of this magnitude, there is no realistic self-help measure a private citizen can take. They cannot personally re-engineer their neighbor's hillside property. This is precisely the kind of large-scale public safety hazard that regulatory laws like the Takuzōhō are designed to address. Government intervention was not just an option; it was essential.

Conclusion

The law in Japan recognizes that when the government is given regulatory power to protect citizens from harm, that power can, under certain circumstances, become a legal duty. While regulators are afforded discretion, they cannot ignore clear, specific, and grave dangers that they have the power to prevent.

To hold the government liable for its inaction, a plaintiff must prove more than just a bad outcome. They must prove that the regulator knew of a foreseeable and serious danger, had the clear legal and factual ability to avert it, and that its failure to do so was not just a simple error but was "grossly lacking in reasonableness." A government's attempt to hide behind a mistaken interpretation of its own legal authority, especially when the law is clear, will not serve as a defense. This framework ensures that while regulators are not held responsible for every accident, they are held accountable when they abdicate their core responsibility to protect public safety in the face of a clear and preventable disaster.