If you look at a map of Kitasenju in Tokyo’s Adachi Ward, you will see that it’s almost entirely surrounded by water.

The Arakawa River to the north and the Sumida River to the south come together and run side by side, just a few hundred meters apart, then diverge before meeting again, like the outline of a python digesting an egg.

Kitasenju is the egg, and last Saturday I discovered how fragile a place it can be to live in. As the rain from Typhoon Hagibis threatened to cause the Arakawa to overflow and flood the whole area, my family and I found ourselves sheltering overnight in the local primary school, fearing that our house would be deluged.

I have lived in Kitasenju for 13 years, and one of the things my family and I like most about it is the Arakawa. The banks are landscaped with parks, soccer fields and baseball diamonds. You can picnic there, or hunt for crabs and grasshoppers, or cycle for miles on flat, smooth paths.

I have always known it could also be dangerous. A friend of mine helped translate a special documentary by public broadcaster NHK on flooding projections in Tokyo, and he warned me that Kitasenju was particularly vulnerable. I tried not to listen. A work colleague wrote an article about the same topic. I gave it only a nervous skim read.

Living in Japan, with its ever-present threat of earthquakes, you are always aware that your life could change in an instant, but it’s not something you can carry around at the forefront of your mind every day. Sometimes, though, you just can’t avoid confronting it.

Like everyone else, I had seen reports that Typhoon Hagibis was coming, and that it was going to be the biggest storm to hit Japan for decades. I was mostly worried about potential damage to our two-story house, which is 40 years old, or losing electricity or water. We bought supplies, hunkered down on Saturday afternoon and prepared to close the storm shutters when the typhoon approached.

The rain had been falling hard all day, and at times I absent-mindedly wondered if there was any risk of the Arakawa overflowing. The levee separating the river from the town below is so high that I never really gave it any serious consideration, until I received an alert on my smartphone at around 3:30 p.m. saying the situation was looking critical.

It is remarkable how people can be so reluctant to sacrifice comfort for safety, even with danger staring you in the face. I had made pizza dough and I was looking forward to cooking dinner with it. I had beer in the fridge, and my kids were enjoying playing Nintendo.

I knew that if the Arakawa were to burst its banks, however, the flooding would be substantial and maybe even life-threatening. Leaving the house felt like an abandonment, but we quickly packed some things and walked five minutes to the local primary school, which had been set up as an evacuation center.

The line was long, and we were told it would take an hour or two before we could register and come in. I was struck by how well-organized everything was, and when we had finally checked in, we were given sheets, blankets, crackers, water, boiled rice and a room of our own to sleep in.

We were lucky compared with the people who had been given floor space in corridors or communal rooms, but the next four hours as we waited until bedtime were tetchy and tense.

My children are 7 and 4, and they had been cooped up inside all day and were restless and full of energy. They wrestled on the floor and banged into the walls, or played with magnets on the blackboard, giving off sharp metallic clacks that set everyone’s nerves on edge.

Others around the school seemed equally short-tempered, while some looked more at ease with the situation. Some chatted or read books, while others anxiously checked their smartphones for the latest news. One elderly woman, probably in her 80s, rubbed her back in preparation for a long night on a hard floor.

Now and then, a chain reaction of shrill alarms would break the low murmur of chatter, as phones throughout the school received alerts that other rivers had burst their banks. I tried to gather whatever information I could, feeling helpless that there was nothing I could do with it anyway.

I managed to get to sleep at 10 p.m., only to wake up an hour later. I looked out the window fearing the worst, only to find that the rain had stopped. The typhoon was supposed to be in full swing, but the trees outside were barely moving.

I woke up several times throughout the night, and each time I looked out the window gave me more confidence that the danger had passed. By the time everyone woke at 7 a.m., I didn’t even feel the need to check outside straight away. We got up and tidied the room, then walked home in brilliant sunshine through dry, undamaged streets.

I felt I had to see the Arakawa with my own eyes before I could relax properly, and the slopes leading up to the levee were busy with other people who apparently felt the same way.

I gasped when I saw the bloated, seething mass of brown water, which had spread its muddy wings over the playing fields on both sides. Gulls perched woozily on a half-submerged toilet block, while Joban Line trains skimmed over the bridge, just meters above the water.

I started to wonder if we might not be better off living somewhere else, in a place not so vulnerable to flooding. But then I began to consider that the flood barriers had been put through the worst-case scenario and still held up, and that we should be feeling more secure than ever.

I went home and watched the news on TV. Houses were flooded and belongings were damaged in Nagano, in Ibaraki, in Fukushima, in Kanagawa. I watched people sweeping mud from their homes and tossing out photos and other irreplaceable mementos that couldn’t be salvaged.

If the rain had kept up in Kitasenju for just a few hours longer, my family would have probably been doing the same.

In a time of both misinformation and too much information, quality journalism is more crucial than ever.
By subscribing, you can help us get the story right.