Urgent measures needed to reduce risks from torrential rains

Torrential rain that is said to normally occur once every few decades has been causing frequent damage. Flood control measures and the construction of flood-resistant towns must be carried out in a planned manner.

The torrential rain that battered the Kyushu region triggered floods and landslides in widespread areas, causing enormous amounts of damage.

Floods caused by climate change will likely continue to occur in many places.

In the wake of torrential rain in western Japan in the summer of 2018, the government drew up a plan for a total of ¥7 trillion over three years to strengthen embankments and dams.

The Liberal Democratic Party insists that the period should be extended and that additional public works projects should be included.

In Kumamoto Prefecture, there had been a plan to build a dam on a tributary of the recently flooded Kuma River, but the administration of the Democratic Party of Japan, taking into account opposition from the prefectural government, decided to cancel the project.

Although it is uncertain whether a dam would have prevented flooding this time, it cannot be said that the prefecture was fully prepared for the recent torrential rains.

Many dam construction projects, such as Shitara Dam in Aichi Prefecture and Ishiki Dam in Nagasaki Prefecture, have been delayed due to concerns about their impact on the environment and their cost.

How can the risk be reduced for disasters that happen one after another? It is necessary for the central and local governments, as well as residents, to seriously discuss the situation while considering their own areas and taking concrete measures. In areas where levees could be breached, efforts should be sped up to improve rivers and raise residential land.

Given the fiscal constraints, there must be a limit to the improvement of infrastructure through spending a huge amount of money. Amid the continuing population decline, the cost-effectiveness of such measures remains questionable. The government should prioritize projects and improve dangerous areas intensively.

It is also important to broaden the scope of flood control to intangible aspects, such as land use that emphasizes disaster prevention and the strengthening of evacuation systems, rather than focusing too much on public works projects.

In the northern Kanto region, which was hit hard by typhoons last autumn, measures are being considered to allow water from upstream areas to flow into fields.

In the previous Diet session, a law was revised to prohibit the building of schools and opening of commercial facilities in areas where the lives of residents could be seriously endangered. In this fiscal year, the government has secured the budget to subsidize the relocation of hospitals and facilities for the elderly where flooding is predicted.

It is significant to support relocation, including of housing, and to consolidate local infrastructure in areas with low disaster risks.

Of course, many people are reluctant to move out of the homes in which they have spent a long time. The government should carefully explain the danger of disasters and seek understanding.

In recent torrential rain disasters, there have been a series of cases in which flood damage predictions on hazard maps coincided with actual flooded areas. It is essential to provide information on flood risks, as well as to secure evacuation facilities, and thoroughly let them be known.