Japanese government decided to make the explanation of a risk of flood damage compulsory from this August 2020. Realtors shall analyse the risk and report it for customers.
In fact these past years abnormal weather increases all over the word.
In 2018 there was a large scale rainfall in west Japan. The above photo (Kyodo) is Okayama prefecture then. The heavy rain caused the river to overflow its banks. Its damage was not only one day. The houses flooded below the floor continued over one month.
I feel there were a lot of rainfall recent years in Osaka, too.
According to a UN report the frequency of abnormal weather is increasing with the years. It is very likely that heavy precipitation events will continue to become more frequent.
(Photo by weather news) West Japan torrential rain in 2018
(purple) above waist
(red) above knee
(yellow) above ankle
(blue) a big rain puddle
In case an individual house may be flooded above the floor. So a property had better be located on elevated ground. Otherwise a house is build on a ground raised by a stone wall like the house below.
In case an apartment when the elevator is flooded and stopped, the upper units of a high rise building will be cut off.
(Photo: Osaka city government’s flood hazard map)
I think Japanese government made the right decision.
After this house hunters should think about the risk of flood damage and realtors shall analyse and report for clients.