Two weeks have passed since a massive mudslide devastated the seaside hot spring resort of Atami in Shizuoka Prefecture.

Suspicions are now being raised that a type of construction work known as “morido” may have contributed to the devastating collapse. Morido involves the use of a huge mass of fill dirt used to level the ground. If this turns out to be true, it suggests man-made factors could be behind the disaster and would warrant a serious investigation to clarify responsibility and craft an effective plan to prevent similar landslides.

The tract in question was purchased in 2006 by a real estate company in Kanagawa Prefecture. The following year, it submitted a morido plan to the Atami municipal government under a Shizuoka prefectural ordinance concerning such soil use. The company’s actions after that have raised many questions.

One baffling fact is that the ground level was raised by an estimated 50 meters, more than three times the maximum height permitted under the submitted plan. How was it possible that the local administration was unaware of such a large-scale change in the plan made without reporting it to the appropriate authority?

Industrial waste was also used. The prefectural and municipal governments say they instructed the company to take corrective action and stop bringing waste to the site. But many questions remain about how the company responded to these instructions and how the local authorities monitored its actions. There is also a possibility that a required earth-fill dam to prevent a landslide was not built as required under the plan.

If many overlooked violations and acts of negligence were a major factor contributing to the disaster, the local administrations should be held severely responsible for what happened. In 2007, a landslide at another site created by the same real estate company alarmed the Atami municipal assembly. The local governments missed out on that opportunity to tackle the problem.

Ownership of the land changed in 2011. The first step in the planned investigation should be to clarify who brought in the huge volume of dirt and when.

The prefectural government plans to set up a task force to identify the causes of the mudflow and determine whether administrative responses to the problems were appropriate. Outside experts should also be called in as exhaustive efforts are made to ascertain the facts.

Collecting images and videos of the construction work will be key. The team also needs to interview as many local residents as possible and question the company responsible for the morido work, as well as the current landowner. To learn why the prefectural and municipal administrations failed to handle the matter appropriately, it will be vital to interview the local government officials involved.

The disaster should herald a sweeping review of morido-related regulations.

There are different kinds of morido projects subject to different rules and regulations. When such work is done to create housing land, the project is subject to the law regulating housing land development, which requires building a retaining wall and drainage facilities. But morido projects for other purposes, such as the one in Atami, are not subject to such measures.

Some 50,000 tracts of land exist nationwide that were developed through large-scale morido work, according to the land ministry.

However, the ministry dose not have information about plots smaller than 3,000 square meters. It needs to work with other government organizations, including the farm ministry and the Environment Ministry, to identify dangerous locations and instruct the businesses involved to take steps to prevent a disaster while alerting local residents to the risk.

It is also necessary to rethink regulatory policies for dealing with these issues and determine the scope of coverage for related laws and ordnances.

In Atami, the search for survivors continues. Some 500 local residents are living in evacuation centers.

Governments at the national and local level must help the victims rebuild their lives while making all-out efforts to identify the causes of this disaster.

--The Asahi Shimbun, July 17