Government to subsidize river dredging work

The central government will subsidize the cost of removing silt from rivers controlled by local governments in an effort to prevent severe flooding, which has occurred many times in recent years following torrential rains.

Removing soil and sand sediment that accumulates at the bottom of rivers can help to prevent dikes from being breached, even when rivers have been swelled by heavy rains.

Depending on the amount of sediment deposited and the population living in the river basin, the central government will provide financial assistance to local governments for silt removal — which has until now been carried out independently by local governments.

A project to promote emergency dredging that was established this fiscal year by the Internal Affairs and Communications Ministry will be introduced under which 70% of the cost of sediment removal on rivers controlled by prefectural governments and municipalities will be covered by the tax revenue allocated to local governments.

The subsidy will also cover the cost of removing sediment that has accumulated at the bottom of an upstream dam.

The government plans to subsidize dredging projects that will take place over the next five years until fiscal 2024. It plans to set aside ¥90 billion to support the project for this fiscal year.

In recent disasters caused by torrential rains, so-called backwater flooding has occurred at points where rivers join.

Backwater flooding is a phenomenon that occurs when heavy rainfall excessively increases the amount of water in large rivers and their tributaries simultaneously, forcing water to flow back upstream.

Local governments have called for the central government to support flood control measures for rivers and tributaries that have experienced serious flooding in the past.

The recent heavy rain in the Kyushu region caused flooding at the Senjuen elderly care home in the village of Kuma, Kumamoto Prefecture, claiming many lives. The overflowing of a tributary running beside the facility is said to have been the cause of the flooding.

According to the land ministry, backwater flooding was observed in the wake of Typhoon No. 19 in October last year at several points along the Abukuma River, which runs through Fukushima and Miyagi prefectures.

Backwater flooding also destroyed dikes in Kurashiki, Okayama Prefecture, when heavy rains battered areas across western Japan in 2018.