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Soka City

To Be a Flood-resistant City

Update : 2021-12-2

Prepare against Torrential Rain
Commitments to Drain, to Store and to Prepare

Flood Damage Considerably Decreased in the Typhoon No.19 in 2019

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Water intrusion area caused by the Typhoon No.26 in 2013
Water intrusion area caused by the Typhoon No.19 in 2019

  Typhoon No.26
October 16, 2013
Typhoon No.19
October 12, 2019
Total amount of rainfall 231.5mm 276.5mm
Maximum amount of rainfall in an hour 41.5mm 42.5mm
Number of roads closed 57 roads 3 roads
Number of roads flooded 70 places 14 places
Wetted surface area 312.6ha 18.07ha
Inundation above floor level 19 places 0 places
Inundation below floor level 138 places 2件 places

Soka City Prone to Flood Damage
Preparation against Torrential Rain Essential

  • The ground of Soka City is low, so torrential rain often causes flood on roads and inundation above or below floor level.
  • The flood damage is decreasing over years, due to the establishment of a drainage pump station, the reinforcement of pumps and the preparation of facilities for storage of rain water. But we still need to prepare against unanticipated torrential rain in daily life.

To Drain

In the drainage facilities in Soka City, the water gates are closed, preventing backward flow from rivers, and water is drained from small rivers to larger rivers with drainage pumps.

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Pumps Established along the River in the South of the Nissato Ground

In addition to the facilities indicated on the map, there are about 200 small-scale facilities in Soka City, and a new pump was established in the south of Nissato Bosai Hiroba (Nissato Ground) to drain water to the Kenaga River.

Nissato Ground image

To Store

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One of the largest facilities for storage of rain water in Soka City completed

This facility was established below the planned site of the Matsubara Tennis Court (tentative name) in Matsubara 4-chome.
The facility can temporarily store about 15,000 m3 of rain water (which would fill a 25-meter swimming pool about 22 times) in case of torrential rain, and can drain it gradually after the water level of rivers was lowered.

To Prepare

To mitigate flood damage to the minimum, we need to make preparation in daily life, such as actions we can take at home and information collection.

  • Clean lateral grooves and drain ditches.
  • Check the weather information frequently.
  • Read the hazard map.
  • Prepare against flood damage from unexpected places.
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Let's make our community flood-resistant.

Flood Fighting Activities to Be Conducted 24 Hours a Day
In Times of Emergency

  • In times of potential flood disaster, city employees will work 24hours a day on the operation of drainage pumps, on the patrol on roads and on the restriction of traffic.
  • Soka City will be engaged in flood fighting activities, collaborating with companies in the city which exchanged contract.

Times of Emergency image

Traffic Guide Markers of Balloon Sandbags to Be Given Trial

Rain- and wind-resistant and Eye-catching in the Height of People

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The flood on roads will be indicated by placing balloon sandbags, ensuring safety, even in dangerous situations of large-scale typhoons or torrential rain.



Kensetsu Kanri-ka (Public Works Management Section)
Tel.(048) 922-2069
FAX(048) 922-3152