Semi-underground buildings

In recent years, from the viewpoint of effective use of land, there has been a lot of movement to use underground as part of parking lots, storerooms, and living rooms.
Flood damage to semi-underground buildings due to typhoons and torrential rainfalls is increasing, and it is important to prevent flooding in residential areas.

What's going on?
Typhoons and torrential rainfalls can cause a large amount of rainwater to flow from roads into buildings and underground parking lots, causing flooding.
Also, when a large amount of rainwater flows into the sewer, the water level of the sewer pipe rises sharply. Underground buildings have floors in the basement.
Because it is lower than roads and ground surfaces, if inundation measures are not sufficient, sewage may flow back from drains such as bathrooms and washrooms in the confluence area.

To protect life and property
Article 19 of the Building Standards Law stipulates that "the site of the building must have appropriate sewer pipes, drains, or other similar facilities for draining or treating rainwater and sewage." I am.
Please check again to make every effort to prevent flooding.
If drainage due to natural flow is difficult, the pump can be installed at the responsibility of the installer.
Rainwater pump drainage facilities are not eligible for the drainage plan confirmation application.