Damage to Water Supply Infrastructure in the City Center

There was a water main break in central Kyoto, and just as I thought it was an isolated incident, a similar event occurred in Osaka as well. Judging from the news footage, the damage in Osaka seemed even more severe than that in Kyoto. Seeing sports grounds submerged and roads flooded sent chills down my spine.

The infrastructure laid during Japan’s period of rapid economic growth is now about 50 to 60 years old, assuming it hasn’t been updated since. Given this, it’s not surprising if such incidents start happening frequently—in fact, it would be wise to assume they will occur with a fairly high probability.

When it comes to natural disasters like floods or landslides, it’s possible to check hazard maps before purchasing a home. However, with water and sewer infrastructure, you can look up when it was installed, but there’s no way to gauge its risk level (or safety level?) from that information alone. At most, you can think about the potential impact of a water outage and how to deal with it.

By the way, did you know that there are multiple types of water supply systems for apartment buildings? Broadly speaking, there are two main types:

• Direct connection systems, which supply tap water straight from the public water mains, and
• Storage tank systems, where water is first stored in a tank and then supplied to the building.

Each of these can be further divided into two subtypes. For direct connection systems, there is the direct pressurized system, where a pump increases the water pressure to supply higher floors, since the standard water pressure isn’t sufficient. For storage tank systems, in addition to the standard type that pumps water from a lower tank to upper floors, there is the elevated tank system, where a tank is placed on the rooftop and water flows down from there.

In the event of a water main break like this one, buildings with a direct connection system will experience an immediate water outage. On the other hand, those with a storage tank system can continue using water for as long as there is water left in the tank.

The same applies during a power outage. Storage tank systems can provide water for a certain period, while direct systems—especially in mid- and high-rise buildings that rely on pumps for water pressure—may lose water supply, depending on the area and local conditions.

That said, even in direct connection systems, if there is an emergency power supply and the pump remains operational, water supply can continue. Conversely, even storage tank systems may suffer an outage if they rely on electrical equipment that becomes nonfunctional.

We take it for granted that water comes out when we turn on the tap—but that only happens because the water infrastructure is properly maintained. In addition to damage to the water mains, power outages or earthquakes can also disrupt the infrastructure.

Why not take this opportunity to check the water supply infrastructure of your own home?

For additional information or any questions please contact us here
Email: info@remax-apex.com