Saitama City Inland Water Hazard Map【English】

What is Inland Water Hazard Map?

This Inland Water Hazard Map shows the inundation area and depth of inundation that can be anticipated in the occurrence of inland water flooding caused by heavy rainfall that exceeds the drainage capacity of the sewerage system, based on inundation simulation.
It was prepared with the aim of promoting self-help and mutual-help among citizens by helping them prepare for everyday needs and evacuation.
On this map's surface, the assumed inundation depths from 20 cm to more than 5 m are color-coded in six levels and indicated by a 25 m × 25 m square.
Please check the depth of inundation in your area and make sure you have a safe evacuation route to move to.
Consider multiple evacuation routes, as the flooded area and depth of flooding may differ from the map due to rainfall and changes in the shape of the land.

Conditions under which the inland water hazard map was created.

This map was prepared based on a simulation of inundation assuming that the maximum possible rainfall (maximum 153 mm, total rainfall 249 mm) would fall on the entire city of Saitama and the water level in the river to be discharged would be high.
The information reflected in the inundation simulation is made based on topographical information such as ground elevation (based on the Geographical Survey Institute's laser surveying 5m mesh (elevation) " approved by the Director of the  Geographical Survey Institute of Japan (Use) R 2JHs 1206 based on the Survey Act") and reflecting major rivers and sewers in the city.
Furthermore, the information on sewerage storage facilities, pump stations, drainage pump stations, gates, etc. is as of the end of 2020.

Cautions for using the Inland Water Hazard Map.

Assumed inundation areas and inundation depths may vary depending on the type of rainfall, the shape of the land, and the maintenance situation of rivers and sewers.
Therefore, it does not mean that the areas indicated on this map always get flooded during heavy rains, but rather that even areas not expected to be inundated may be inundated depending on the situation, so please be very careful.
This map does not take class A rivers overflow (flooding) into account, so please  check the latest flood hazard map as well.